1. Guide Overview

The purpose of this guide is to walk through the steps that need to be completed prior to booting up the Keycloak server for the first time. If you just want to test drive Keycloak, it pretty much runs out of the box with its own embedded and local-only database. For actual deployments that are going to be run in production you’ll need to decide how you want to manage server configuration at runtime (standalone or domain mode), configure a shared database for Keycloak storage, set up encryption and HTTPS, and finally set up Keycloak to run in a cluster. This guide walks through each and every aspect of any pre-boot decisions and setup you must do prior to deploying the server.

One thing to particularly note is that Keycloak is derived from the WildFly Application Server. Many aspects of configuring Keycloak revolve around WildFly configuration elements. Often this guide will direct you to documentation outside of the manual if you want to dive into more detail.

Keycloak is built on top of the WildFly application server and it’s sub-projects like Infinispan (for caching) and Hibernate (for persistence). This guide only covers basics for infrastructure-level configuration. It is highly recommended that you peruse the documentation for WildFly and its sub projects. Here is the link to the documentation:

2. Installation

Installing Keycloak is as simple as downloading it and unzipping it. This chapter reviews system requirements as well as the directory structure of the distribution.

2.1. System Requirements

These are the requirements to run the Keycloak authentication server:

  • Can run on any operating system that runs Java

  • Java 8 JDK

  • zip or gzip and tar

  • At least 512M of RAM

  • At least 1G of diskspace

  • A shared external database like Postgres, MySql, Oracle, etc. Keycloak requires an external shared database if you want to run in a cluster. Please see the database configuration section of this guide for more information.

  • Network multicast support on your machine if you want to run in a cluster. Keycloak can be clustered without multicast, but this requires a bunch of configuration changes. Please see the clustering section of this guide for more information.

  • On Linux, it is recommended to use /dev/urandom as a source of random data to prevent Keycloak hanging due to lack of available entropy, unless /dev/random usage is mandated by your security policy. To achieve that on Oracle JDK 8 and OpenJDK 8, set the java.security.egd system property on startup to file:/dev/urandom.

2.2. Installing Distribution Files

The Keycloak Server has three downloadable distributions:

  • 'keycloak-3.4.0.CR1.[zip|tar.gz]'

  • 'keycloak-overlay-3.4.0.CR1.[zip|tar.gz]'

  • 'keycloak-demo-3.4.0.CR1.[zip|tar.gz]'

The 'keycloak-3.4.0.CR1.[zip|tar.gz]' file is the server only distribution. It contains nothing other than the scripts and binaries to run the Keycloak Server. To unpack this file just run your operating system’s unzip or gunzip and tar utilities.

The 'keycloak-overlay-3.4.0.CR1.[zip|tar.gz]' file is a Wildfly add-on that allows you to install Keycloak Server on top of an existing WildFly distribution. We do not support users that want to run their applications and Keycloak on the same server instance. To install the Keycloak Service Pack, just unzip it in the root directory of your WildFly distribution, open the bin directory in a shell and run ./jboss-cli.[sh|bat] --file=keycloak-install.cli.

The 'keycloak-demo-3.4.0.CR1.[zip|tar.gz]' contains the server binaries, all documentation and all examples. It is preconfigured with both the OIDC and SAML client application adapters and can deploy any of the distribution examples out of the box with no configuration. This distribution is only recommended for those that want to test drive Keycloak. We do not support users that run the demo distribution in production.

To unpack of these files run the unzip or gunzip and tar utilities.

2.3. Distribution Directory Structure

This chapter walks you through the directory structure of the server distribution.

distribution directory structure


Let’s examine the purpose of some of the directories:


This contains various scripts to either boot the server or perform some other management action on the server.


This contains configuration files and working directory when running Keycloak in domain mode.


These are all the Java libraries used by the server.


If you are writing extensions to keycloak, you can put your extensions here. See the Server Developer Guide for more information on this.


This contains configuration files and working directory when running Keycloak in standalone mode.


This directory contains all the html, style sheets, javascript files, and images used to display any UI screen displayed by the server. Here you can modify an existing theme or create your own. See the Server Developer Guide for more information on this.

3. Choosing an Operating Mode

Before deploying Keycloak in a production environment you need to decide which type of operating mode you are going to use. Will you run Keycloak within a cluster? Do you want a centralized way to manage your server configurations? Your choice of operating mode effects how you configure databases, configure caching and even how you boot the server.

The Keycloak is built on top of the WildFly Application Server. This guide will only go over the basics for deployment within a specific mode. If you want specific information on this, a better place to go would be the WildFly 10 Documentation.

3.1. Standalone Mode

Standalone operating mode is only useful when you want to run one, and only one Keycloak server instance. It is not usable for clustered deployments and all caches are non-distributed and local-only. It is not recommended that you use standalone mode in production as you will have a single point of failure. If your standalone mode server goes down, users will not be able to log in. This mode is really only useful to test drive and play with the features of Keycloak

3.1.1. Standalone Boot Script

When running the server in standalone mode, there is a specific script you need to run to boot the server depending on your operating system. These scripts live in the bin/ directory of the server distribution.

Standalone Boot Scripts

standalone boot files

To boot the server:

$ .../bin/standalone.sh
> ...\bin\standalone.bat

3.1.2. Standalone Configuration

The bulk of this guide walks you through how to configure infrastructure level aspects of Keycloak. These aspects are configured in a configuration file that is specific to the application server that Keycloak is a derivative of. In the standalone operation mode, this file lives in …​/standalone/configuration/standalone.xml. This file is also used to configure non-infrastructure level things that are specific to Keycloak components.

Standalone Config File

standalone config file

Any changes you make to this file while the server is running will not take effect and may even be overwritten by the server. Instead use the the command line scripting or the web console of WildFly. See the WildFly 10 Documentation for more information.

3.2. Standalone Clustered Mode

Standalone clustered operation mode is for when you want to run Keycloak within a cluster. This mode requires that you have a copy of the Keycloak distribution on each machine you want to run a server instance. This mode can be very easy to deploy initially, but can become quite cumbersome. To make a configuration change you’ll have to modify each distribution on each machine. For a large cluster this can become time consuming and error prone.

3.2.1. Standalone Clustered Configuration

The distribution has a mostly pre-configured app server configuration file for running within a cluster. It has all the specific infrastructure settings for networking, databases, caches, and discovery. This file resides in …​/standalone/configuration/standalone-ha.xml. There’s a few things missing from this configuration. You can’t run Keycloak in a cluster without a configuring a shared database connection. You also need to deploy some type of load balancer in front of the cluster. The clustering and database sections of this guide walk you though these things.

Standalone HA Config

standalone ha config file

Any changes you make to this file while the server is running will not take effect and may even be overwritten by the server. Instead use the the command line scripting or the web console of WildFly. See the WildFly 10 Documentation for more information.

3.2.2. Standalone Clustered Boot Script

You use the same boot scripts to start Keycloak as you do in standalone mode. The difference is that you pass in an additional flag to point to the HA config file.

Standalone Clustered Boot Scripts

standalone boot files

To boot the server:

$ .../bin/standalone.sh --server-config=standalone-ha.xml
> ...\bin\standalone.bat --server-config=standalone-ha.xml

3.3. Domain Clustered Mode

Domain mode is a way to centrally manage and publish the configuration for your servers.

Running a cluster in standard mode can quickly become aggravating as the cluster grows in size. Every time you need to make a configuration change, you have perform it on each node in the cluster. Domain mode solves this problem by providing a central place to store and publish configuration. It can be quite complex to set up, but it is worth it in the end. This capability is built into the WildFly Application Server which Keycloak derives from.

The guide will go over the very basics of domain mode. Detailed steps on how to set up domain mode in a cluster should be obtained from the WildFly 10 Documentation.

Here are some of the basic concepts of running in domain mode.

domain controller

The domain controller is a process that is responsible for storing, managing, and publishing the general configuration for each node in the cluster. This process is the central point from which nodes in a cluster obtain their configuration.

host controller

The host controller is responsible for managing server instances on a specific machine. You configure it to run one or more server instances. The domain controller can also interact with the host controllers on each machine to manage the cluster. To reduce the number of running process, a domain controller also acts as a host controller on the machine it runs on.

domain profile

A domain profile is a named set of configuration that can be used by a server to boot from. A domain controller can define multiple domain profiles that are consumed by different servers.

server group

A server group is a collection of servers. They are managed and configured as one. You can assign a domain profile to a server group and every service in that group will use that domain profile as their configuration.

In domain mode, a domain controller is started on a master node. The configuration for the cluster resides in the domain controller. Next a host controller is started on each machine in the cluster. Each host controller deployment configuration specifies how many Keycloak server instances will be started on that machine. When the host controller boots up, it starts as many Keycloak server instances as it was configured to do. These server instances pull their configuration from the domain controller.

3.3.1. Domain Configuration

Various other chapters in this guide walk you through configuring various aspects like databases, HTTP network connections, caches, and other infrastructure related things. While standalone mode uses the standalone.xml file to configure these things, domain mode uses the …​/domain/configuration/domain.xml configuration file. This is where the domain profile and server group for the Keycloak server are defined.


domain file

Any changes you make to this file while the domain controller is running will not take effect and may even be overwritten by the server. Instead use the the command line scripting or the web console of WildFly. See the WildFly 10 Documentation for more information.

Let’s look at some aspects of this domain.xml file. The auth-server-standalone and auth-server-clustered profile XML blocks are where you are going to make the bulk of your configuration decisions. You’ll be configuring things here like network connections, caches, and database connections.

auth-server profile
        <profile name="auth-server-standalone">
       <profile name="auth-server-clustered">

The auth-server-standalone profile is a non-clustered setup. The auth-server-clustered profile is the clustered setup.

If you scroll down further, you’ll see various socket-binding-groups defined.

        <socket-binding-group name="standard-sockets" default-interface="public">
        <socket-binding-group name="ha-sockets" default-interface="public">
        <!-- load-balancer-sockets should be removed in production systems and replaced with a better softare or hardare based one -->
        <socket-binding-group name="load-balancer-sockets" default-interface="public">

This config defines the default port mappings for various connectors that are opened with each Keycloak server instance. Any value that contains ${…​} is a value that can be overriden on the command line with the -D switch, i.e.

$ domain.sh -Djboss.http.port=80

The definition of the server group for Keycloak resides in the server-groups XML block. It specifies the domain profile that is used (default) and also some default boot arguments for the Java VM when the host controller boots an instance. It also binds a socket-binding-group to the server group.

server group
        <!-- load-balancer-group should be removed in production systems and replaced with a better softare or hardare based one -->
        <server-group name="load-balancer-group" profile="load-balancer">
            <jvm name="default">
                <heap size="64m" max-size="512m"/>
            <socket-binding-group ref="load-balancer-sockets"/>
        <server-group name="auth-server-group" profile="auth-server-clustered">
            <jvm name="default">
                <heap size="64m" max-size="512m"/>
            <socket-binding-group ref="ha-sockets"/>

3.3.2. Host Controller Configuration

Keycloak comes with two host controller configuration files that reside in the …​/domain/configuration/ directory: host-master.xml and host-slave.xml. host-master.xml is configured to boot up a domain controller, a load balancer, and one Keycloak server instance. host-slave.xml is configured to talk to the domain controller and boot up one Keycloak server instance.

The load balancer is not a required service. It exists so that you can easily test drive clustering on your development machine. While usable in production, you have the option of replacing it if you have a different hardware or software based load balancer you want to use.
Host Controller Config

host files

To disable the load balancer server instance, edit host-master.xml and comment out or remove the "load-balancer" entry.

        <!-- remove or comment out next line -->
        <server name="load-balancer" group="loadbalancer-group"/>

Another interesting thing to note about this file is the declaration of the authentication server instance. It has a port-offset setting. Any network port defined in the domain.xml socket-binding-group or the server group will have the value of port-offset added to it. For this example domain setup we do this so that ports opened by the load balancer server don’t conflict with the authentication server instance that is started.

        <server name="server-one" group="auth-server-group" auto-start="true">
             <socket-bindings port-offset="150"/>

3.3.3. Server Instance Working Directories

Each Keycloak server instance defined in your host files creates a working directory under …​/domain/servers/{SERVER NAME}. Additional configuration can be put there, and any temporary, log, or data files the server instance needs or creates go there too. The structure of these per server directories ends up looking like any other WildFly booted server.

Working Directories

domain server dir

3.3.4. Domain Boot Script

When running the server in domain mode, there is a specific script you need to run to boot the server depending on your operating system. These scripts live in the bin/ directory of the server distribution.

Domain Boot Script

domain boot files

To boot the server:

$ .../bin/domain.sh --host-config=host-master.xml
> ...\bin\domain.bat --host-config=host-slave.xml

When running the boot script you will need pass in the host controlling configuration file you are going to use via the --host-config switch.

3.3.5. Clustered Domain Example

You can test drive clustering using the out-of-the-box domain.xml configuration. This example domain is meant to run on one machine and boots up:

  • a domain controller

  • an HTTP load balancer

  • 2 Keycloak server instances

To simulate running a cluster on two machines, you’ll run the domain.sh script twice to start two separate host controllers. The first will be the master host controller which will start a domain controller, an HTTP load balancer, and one Keycloak authentication server instance. The second will be a slave host controller that only starts up an authentication server instance.

Setup Slave Connection to Domain Controller

Before you can boot things up though, you have to configure the slave host controller so that it can talk securely to the domain controller. If you do not do this, then the slave host will not be able to obtain the centralized configuration from the domain controller. To set up a secure connection, you have to create a server admin user and a secret that will be shared between the master and the slave. You do this by running the …​/bin/add-user.sh script.

When you run the script select Management User and answer yes when it asks you if the new user is going to be used for one AS process to connect to another. This will generate a secret that you’ll need to cut and paste into the …​/domain/configuration/host-slave.xml file.

Add App Server Admin
$ add-user.sh
 What type of user do you wish to add?
  a) Management User (mgmt-users.properties)
  b) Application User (application-users.properties)
 (a): a
 Enter the details of the new user to add.
 Using realm 'ManagementRealm' as discovered from the existing property files.
 Username : admin
 Password recommendations are listed below. To modify these restrictions edit the add-user.properties configuration file.
  - The password should not be one of the following restricted values {root, admin, administrator}
  - The password should contain at least 8 characters, 1 alphabetic character(s), 1 digit(s), 1 non-alphanumeric symbol(s)
  - The password should be different from the username
 Password :
 Re-enter Password :
 What groups do you want this user to belong to? (Please enter a comma separated list, or leave blank for none)[ ]:
 About to add user 'admin' for realm 'ManagementRealm'
 Is this correct yes/no? yes
 Added user 'admin' to file '/.../standalone/configuration/mgmt-users.properties'
 Added user 'admin' to file '/.../domain/configuration/mgmt-users.properties'
 Added user 'admin' with groups to file '/.../standalone/configuration/mgmt-groups.properties'
 Added user 'admin' with groups to file '/.../domain/configuration/mgmt-groups.properties'
 Is this new user going to be used for one AS process to connect to another AS process?
 e.g. for a slave host controller connecting to the master or for a Remoting connection for server to server EJB calls.
 yes/no? yes
 To represent the user add the following to the server-identities definition <secret value="bWdtdDEyMyE=" />
The add-user.sh does not add user to Keycloak server but to the underlying JBoss Enterprise Application Platform. The credentials used and generated in the above script are only for example purpose. Please use the ones generated on your system.

Now cut and paste the secret value into the …​/domain/configuration/host-slave.xml file as follows:

             <security-realm name="ManagementRealm">
                     <secret value="bWdtdDEyMyE="/>
Run the Boot Scripts

Since we’re simulating a two node cluster on one development machine, you’ll run the boot script twice:

Boot up master
$ domain.sh --host-config=host-master.xml
Boot up slave
$ domain.sh --host-config=host-slave.xml

To try it out, open your browser and go to http://localhost:8080/auth

4. Manage Subsystem Configuration

Low-level configuration of Keycloak is done by editing the standalone.xml, standalone-ha.xml, or domain.xml file in your distribution. The location of this file depends on your operating mode.

While there are endless settings you can configure here, this section will focus on configuration of the keycloak-server subsystem. No matter which configuration file you are using, configuration of the keycloak-server subsystem is the same.

The keycloak-server subsystem is typically declared toward the end of the file like this:

<subsystem xmlns="urn:jboss:domain:keycloak-server:1.1">

Note that anything changed in this subsystem will not take effect until the server is rebooted.

4.1. Configure SPI Providers

The specifics of each configuration setting is discussed elsewhere in context with that setting. However, it is useful to understand the format used to declare settings on SPI providers.

Keycloak is a highly modular system that allows great flexibility. There are more than 50 service provider interfaces (SPIs), and you are allowed to swap out implementations of each SPI. An implementation of an SPI is known as a provider.

All elements in an SPI declaration are optional, but a full SPI declaration looks like this:

<spi name="myspi">
    <provider name="myprovider" enabled="true">
            <property name="foo" value="bar"/>
    <provider name="mysecondprovider" enabled="true">
            <property name="foo" value="foo"/>

Here we have two providers defined for the SPI myspi. The default-provider is listed as myprovider. However it is up to the SPI to decide how it will treat this setting. Some SPIs allow more than one provider and some do not. So default-provider can help the SPI to choose.

Also notice that each provider defines its own set of configuration properties. The fact that both providers above have a property called foo is just a coincidence.

The type of each property value is interpreted by the provider. However, there is one exception. Consider the jpa provider for the eventStore API:

<spi name="eventsStore">
    <provider name="jpa" enabled="true">
            <property name="exclude-events" value="[&quot;EVENT1&quot;,

We see that the value begins and ends with square brackets. That means that the value will be passed to the provider as a list. In this example, the system will pass the provider a list with two element values EVENT1 and EVENT2. To add more values to the list, just separate each list element with a comma. Unfortunately, you do need to escape the quotes surrounding each list element with &quot;.

4.2. Start the WildFly CLI

Besides editing the configuration by hand, you also have the option of changing the configuration by issuing commands via the jboss-cli tool. CLI allows you to configure servers locally or remotely. And it is especially useful when combined with scripting.

To start the WildFly CLI, you need to run jboss-cli.

$ .../bin/jboss-cli.sh
> ...\bin\jboss-cli.bat

This will bring you to a prompt like this:

[disconnected /]

If you wish to execute commands on a running server, you will first execute the connect command.

[disconnected /] connect
[standalone@localhost:9990 /]

You may be thinking to yourself, "I didn’t enter in any username or password!". If you run jboss-cli on the same machine as your running standalone server or domain controller and your account has appropriate file permissions, you do not have to setup or enter in a admin username and password. See the WildFly 10 Documentation for more details on how to make things more secure if you are uncomfortable with that setup.

4.3. CLI Embedded Mode

If you do happen to be on the same machine as your standalone server and you want to issue commands while the server is not active, you can embed the server into CLI and make changes in a special mode that disallows incoming requests. To do this, first execute the embed command with the config file you wish to change.

[disconnected /] embed-server --server-config=standalone.xml
[standalone@embedded /]

4.4. CLI GUI Mode

The CLI can also run in GUI mode. GUI mode launches a Swing application that allows you to graphically view and edit the entire management model of a running server. GUI mode is especially useful when you need help formatting your CLI commands and learning about the options available. The GUI can also retrieve server logs from a local or remote server.

Start in GUI mode
$ .../bin/jboss-cli.sh --gui

Note: to connect to a remote server, you pass the --connect option as well. Use the --help option for more details.

After launching GUI mode, you will probably want to scroll down to find the node, subsystem=keycloak-server. If you right-click on the node and click Explore subsystem=keycloak-server, you will get a new tab that shows only the keycloak-server subsystem.

cli gui

4.5. CLI Scripting

The CLI has extensive scripting capabilities. A script is just a text file with CLI commands in it. Consider a simple script that turns off theme and template caching.


To execute the script, I can follow the Scripts menu in CLI GUI, or execute the script from the command line as follows:

$ .../bin/jboss-cli.sh --file=turn-off-caching.cli

4.6. CLI Recipes

Here are some configuration tasks and how to perform them with CLI commands. Note that in all but the first example, we use the wildcard path ** to mean you should substitute or the path to the keycloak-server subsystem.

For standalone, this just means:

** = /subsystem=keycloak-server

For domain mode, this would mean something like:

** = /profile=auth-server-clustered/subsystem=keycloak-server

4.6.1. Change the web context of the server


4.6.2. Set the global default theme


4.6.3. Add a new SPI and a provider


4.6.4. Disable a provider


4.6.5. Change the default provider for an SPI


4.6.6. Configure the dblock SPI

**/spi=dblock/provider=jpa/:add(properties={lockWaitTimeout => "900"},enabled=true)

4.6.7. Add or change a single property value for a provider


4.6.8. Remove a single property from a provider


4.6.9. Set values on a provider property of type List


5. Profiles

Keycloak has a single profile, community, that enables most features by default, including features that are considered less mature. It is however possible to disable individual features.

The features that can be enabled and disabled are:

Name Description Enabled by default


Authorization Services



Docker Registry protocol



Ability for admins to impersonate users



Write custom authenticators using JavaScript


To enable a specific feature start the server with:

bin/standalone.sh|bat -Dkeycloak.profile.feature.<feature name>=disabled

For example to enable Docker use -Dkeycloak.profile.feature.docker=enabled.

To disable a specific feature start the server with:

bin/standalone.sh|bat -Dkeycloak.profile.feature.<feature name>=disabled

For example to disable Impersonation use -Dkeycloak.profile.feature.impersonation=disabled.

You can set this permanently in the profile.properties file by adding:


6. Relational Database Setup

Keycloak comes with its own embedded Java-based relational database called H2. This is the default database that Keycloak will use to persist data and really only exists so that you can run the authentication server out of the box. We highly recommend that you replace it with a more production ready external database. The H2 database is not very viable in high concurrency situations and should not be used in a cluster either. The purpose of this chapter is to show you how to connect Keycloak to a more mature database.

Keycloak uses two layered technologies to persist its relational data. The bottom layered technology is JDBC. JDBC is a Java API that is used to connect to a RDBMS. There are different JDBC drivers per database type that are provided by your database vendor. This chapter discusses how to configure Keycloak to use one of these vendor-specific drivers.

The top layered technology for persistence is Hibernate JPA. This is a object to relational mapping API that maps Java Objects to relational data. Most deployments of Keycloak will never have to touch the configuration aspects of Hibernate, but we will discuss how that is done if you run into that rare circumstance.

Datasource configuration is covered much more thoroughly in the datasource configuration chapter in the WildFly 10 Documentation.

6.1. RDBMS Setup Checklist

These are the steps you will need to perform to get an RDBMS configured for Keycloak.

  1. Locate and download a JDBC driver for your database

  2. Package the driver JAR into a module and install this module into the server

  3. Declare the JDBC driver in the configuration profile of the server

  4. Modify the datasource configuration to use your database’s JDBC driver

  5. Modify the datasource configuration to define the connection parameters to your database

This chapter will use PostgresSQL for all its examples. Other databases follow the same steps for installation.

6.2. Package the JDBC Driver

Find and download the JDBC driver JAR for your RDBMS. Before you can use this driver, you must package it up into a module and install it into the server. Modules define JARs that are loaded into the Keycloak classpath and the dependencies those JARs have on other modules. They are pretty simple to set up.

Within the …​/modules/ directory of your Keycloak distribution, you need to create a directory structure to hold your module definition. The convention is use the Java package name of the JDBC driver for the name of the directory structure. For PostgreSQL, create the directory org/postgresql/main. Copy your database driver JAR into this directory and create an empty module.xml file within it too.

Module Directory

db module

After you have done this, open up the module.xml file and create the following XML:

Module XML
<?xml version="1.0" ?>
<module xmlns="urn:jboss:module:1.3" name="org.postgresql">

        <resource-root path="postgresql-9.4.1212.jar"/>

        <module name="javax.api"/>
        <module name="javax.transaction.api"/>

The module name should match the directory structure of your module. So, org/postgresql maps to org.postgresql. The resource-root path attribute should specify the JAR filename of the driver. The rest are just the normal dependencies that any JDBC driver JAR would have.

6.3. Declare and Load JDBC Driver

The next thing you have to do is declare your newly packaged JDBC driver into your deployment profile so that it loads and becomes available when the server boots up. Where you perform this action depends on your operating mode. If you’re deploying in standard mode, edit …​/standalone/configuration/standalone.xml. If you’re deploying in standard clustering mode, edit …​/standalone/configuration/standalone-ha.xml. If you’re deploying in domain mode, edit …​/domain/configuration/domain.xml. In domain mode, you’ll need to make sure you edit the profile you are using: either auth-server-standalone or auth-server-clustered

Within the profile, search for the drivers XML block within the datasources subsystem. You should see a pre-defined driver declared for the H2 JDBC driver. This is where you’ll declare the JDBC driver for your external database.

JDBC Drivers
  <subsystem xmlns="urn:jboss:domain:datasources:4.0">
          <driver name="h2" module="com.h2database.h2">

Within the drivers XML block you’ll need to declare an additional JDBC driver. It needs to have a name which you can choose to be anything you want. You specify the module attribute which points to the module package you created earlier for the driver JAR. Finally you have to specify the driver’s Java class. Here’s an example of installing PostgreSQL driver that lives in the module example defined earlier in this chapter.

Declare Your JDBC Drivers
  <subsystem xmlns="urn:jboss:domain:datasources:4.0">
          <driver name="postgresql" module="org.postgresql">
          <driver name="h2" module="com.h2database.h2">

6.4. Modify the Keycloak Datasource

After declaring your JDBC driver, you have to modify the existing datasource configuration that Keycloak uses to connect it to your new external database. You’ll do this within the same configuration file and XML block that you registered your JDBC driver in. Here’s an example that sets up the connection to your new database:

Declare Your JDBC Drivers
  <subsystem xmlns="urn:jboss:domain:datasources:4.0">
       <datasource jndi-name="java:jboss/datasources/KeycloakDS" pool-name="KeycloakDS" enabled="true" use-java-context="true">

Search for the datasource definition for KeycloakDS. You’ll first need to modify the connection-url. The documentation for your vendor’s JDBC implementation should specify the format for this connection URL value.

Next define the driver you will use. This is the logical name of the JDBC driver you declared in the previous section of this chapter.

It is expensive to open a new connection to a database every time you want to perform a transaction. To compensate, the datasource implementation maintains a pool of open connections. The max-pool-size specifies the maximum number of connections it will pool. You may want to change the value of this depending on the load of your system.

Finally, with PostgreSQL at least, you need to define the database username and password that is needed to connect to the database. You may be worried that this is in clear text in the example. There are methods to obfuscate this, but this is beyond the scope of this guide.

For more information about datasource features, see the datasource configuration chapter in the WildFly 10 Documentation.

6.5. Database Configuration

The configuration for this component is found in the standalone.xml, standalone-ha.xml, or domain.xml file in your distribution. The location of this file depends on your operating mode.

Database Config
<subsystem xmlns="urn:jboss:domain:keycloak-server:1.1">
    <spi name="connectionsJpa">
     <provider name="default" enabled="true">
             <property name="dataSource" value="java:jboss/datasources/KeycloakDS"/>
             <property name="initializeEmpty" value="false"/>
             <property name="migrationStrategy" value="manual"/>
             <property name="migrationExport" value="${jboss.home.dir}/keycloak-database-update.sql"/>

Possible configuration options are:


JNDI name of the dataSource


boolean property to specify if datasource is JTA capable


Value of database dialect. In most cases you don’t need to specify this property as dialect will be autodetected by Hibernate.


Initialize database if empty. If set to false the database has to be manually initialized. If you want to manually initialize the database set migrationStrategy to manual which will create a file with SQL commands to initialize the database. Defaults to true.


Strategy to use to migrate database. Valid values are update, manual and validate. Update will automatically migrate the database schema. Manual will export the required changes to a file with SQL commands that you can manually execute on the database. Validate will simply check if the database is up-to-date.


Path for where to write manual database initialization/migration file.


Specify whether Hibernate should show all SQL commands in the console (false by default). This is very verbose!


Specify whether Hibernate should format SQL commands (true by default)


Will log global statistics from Hibernate about executed DB queries and other things. Statistics are always reported to server log at specified interval (in seconds) and are cleared after each report.


Specify the database schema to use

These configuration switches and more are described in the JBoss EAP Development Guide.

6.6. Unicode Considerations for Databases

Database schema in Keycloak only accounts for Unicode strings in the following special fields:

  • Realms: display name, HTML display name

  • Federation Providers: display name

  • Users: username, given name, last name, attribute names and values

  • Groups: name, attribute names and values

  • Roles: name

  • Descriptions of objects

Otherwise, characters are limited to those contained in database encoding which is often 8-bit. However, for some database systems, it is possible to enable UTF-8 encoding of Unicode characters and use full Unicode character set in all text fields. Often, this is counterbalanced by shorter maximum length of the strings than in case of 8-bit encodings.

Some of the databases require special settings to database and/or JDBC driver to be able to handle Unicode characters. Please find the settings for your database below. Note that if a database is listed here, it can still work properly provided it handles UTF-8 encoding properly both on the level of database and JDBC driver.

Technically, the key criterion for Unicode support for all fields is whether the database allows setting of Unicode character set for VARCHAR and CHAR fields. If yes, there is a high chance that Unicode will be plausible, usually at the expense of field length. If it only supports Unicode in NVARCHAR and NCHAR fields, Unicode support for all text fields is unlikely as Keycloak schema uses VARCHAR and CHAR fields extensively.

6.6.1. Oracle Database

Unicode characters are properly handled provided the database was created with Unicode support in VARCHAR and CHAR fields (e.g. by using AL32UTF8 character set as the database character set). No special settings is needed for JDBC driver.

If the database character set is not Unicode, then to use Unicode characters in the special fields, the JDBC driver needs to be configured with the connection property oracle.jdbc.defaultNChar set to true. It might be wise, though not strictly necessary, to also set the oracle.jdbc.convertNcharLiterals connection property to true. These properties can be set either as system properties or as connection properties. Please note that setting oracle.jdbc.defaultNChar may have negative impact on performance. For details, please refer to Oracle JDBC driver configuration documentation.

6.6.2. Microsoft SQL Server Database

Unicode characters are properly handled only for the special fields. No special settings of JDBC driver or database is necessary.

6.6.3. IBM DB2 Database

Unicode characters are properly handled for all fields, length reduction applies to non-special fields. No special settings of JDBC driver or database is necessary.

6.6.4. MySQL Database

Unicode characters are properly handled provided the database was created with Unicode support in VARCHAR and CHAR fields in the CREATE DATABASE command (e.g. by using utf8 character set as the default database character set in MySQL 5.5. Please note that utf8mb4 character set does not work due to different storage requirements to utf8 character set [1]). Note that in this case, length restriction to non-special fields does not apply because columns are created to accomodate given amount of characters, not bytes. If the database default character set does not allow storing Unicode, only the special fields allow storing Unicode values.

At the side of JDBC driver settings, it is necessary to add a connection property characterEncoding=UTF-8 to the JDBC connection settings.

6.6.5. PostgreSQL Database

Unicode is supported when the database character set is UTF8. In that case, Unicode characters can be used in any field, there is no reduction of field length for non-special fields. No special settings of JDBC driver is necessary.

7. Network Setup

Keycloak can run out of the box with some networking limitations. For one, all network endpoints bind to localhost so the auth server is really only usable on one local machine. For HTTP based connections, it does not use default ports like 80 and 443. HTTPS/SSL is not configured out of the box and without it, Keycloak has many security vulnerabilities. Finally, Keycloak may often need to make secure SSL and HTTPS connections to external servers and thus need a trust store set up so that endpoints can be validated correctly. This chapter discusses all of these things.

7.1. Bind Addresses

By default Keycloak binds to the localhost loopback address That’s not a very useful default if you want the authentication server available on your network. Generally, what we recommend is that you deploy a reverse proxy or load balancer on a public network and route traffic to individual Keycloak server instances on a private network. In either case though, you still need to set up your network interfaces to bind to something other than localhost.

Setting the bind address is quite easy and can be done on the command line with either the standalone.sh or domain.sh boot scripts discussed in the Choosing an Operating Mode chapter.

$ standalone.sh -b

The -b switch sets the IP bind address for any public interfaces.

Alternatively, if you don’t want to set the bind address at the command line, you can edit the profile configuration of your deployment. Open up the profile configuration file (standalone.xml or domain.xml depending on your operating mode) and look for the interfaces XML block.

        <interface name="management">
            <inet-address value="${jboss.bind.address.management:}"/>
        <interface name="public">
            <inet-address value="${jboss.bind.address:}"/>

The public interface corresponds to subsystems creating sockets that are available publicly. An example of one of these subsystems is the web layer which serves up the authentication endpoints of Keycloak. The management interface corresponds to sockets opened up by the management layer of the WildFly. Specifically the sockets which allow you to use the jboss-cli.sh command line interface and the WildFly web console.

In looking at the public interface you see that it has a special string ${jboss.bind.address:}. This string denotes a value that can be overriden on the command line by setting a Java system property, i.e.:

$ domain.sh -Djboss.bind.address=

The -b is just a shorthand notation for this command. So, you can either change the bind address value directly in the profile config, or change it on the command line when you boot up.

There are many more options available when setting up interface definitions. For more information, see the network interface in the WildFly 10 Documentation.

7.2. Socket Port Bindings

The ports opened for each socket have a pre-defined default that can be overriden at the command line or within configuration. To illustrate this configuration, let’s pretend you are running in standalone mode and open up the …​/standalone/configuration/standalone.xml. Search for socket-binding-group.

    <socket-binding-group name="standard-sockets" default-interface="public" port-offset="${jboss.socket.binding.port-offset:0}">
        <socket-binding name="management-http" interface="management" port="${jboss.management.http.port:9990}"/>
        <socket-binding name="management-https" interface="management" port="${jboss.management.https.port:9993}"/>
        <socket-binding name="ajp" port="${jboss.ajp.port:8009}"/>
        <socket-binding name="http" port="${jboss.http.port:8080}"/>
        <socket-binding name="https" port="${jboss.https.port:8443}"/>
        <socket-binding name="txn-recovery-environment" port="4712"/>
        <socket-binding name="txn-status-manager" port="4713"/>
        <outbound-socket-binding name="mail-smtp">
            <remote-destination host="localhost" port="25"/>

socket-bindings define socket connections that will be opened by the server. These bindings specify the interface (bind address) they use as well as what port number they will open. The ones you will be most interested in are:


Defines the port used for Keycloak HTTP connections


Defines the port used for Keycloak HTTPS connections


This socket binding defines the port used for the AJP protocol. This protocol is used by Apache HTTPD server in conjunction mod-cluster when you are using Apache HTTPD as a load balancer.


Defines the HTTP connection used by WildFly CLI and web console.

When running in domain mode setting the socket configurations is a bit trickier as the example domain.xml file has multiple socket-binding-groups defined. If you scroll down to the server-group definitions you can see what socket-binding-group is used for each server-group.

domain socket bindings
        <server-group name="load-balancer-group" profile="load-balancer">
            <socket-binding-group ref="load-balancer-sockets"/>
        <server-group name="auth-server-group" profile="auth-server-clustered">
            <socket-binding-group ref="ha-sockets"/>
There are many more options available when setting up socket-binding-group definitions. For more information, see the socket binding group in the WildFly 10 Documentation.

7.3. Setting up HTTPS/SSL

Keycloak is not set up by default to handle SSL/HTTPS. It is highly recommended that you either enable SSL on the Keycloak server itself or on a reverse proxy in front of the Keycloak server.

This default behavior is defined by the SSL/HTTPS mode of each Keycloak realm. This is discussed in more detail in the Server Administration Guide, but let’s give some context and a brief overview of these modes.

external requests

Keycloak can run out of the box without SSL so long as you stick to private IP addresses like localhost,, 10.0.x.x, 192.168.x.x, and 172..16.x.x. If you don’t have SSL/HTTPS configured on the server or you try to access Keycloak over HTTP from a non-private IP adress you will get an error.


Keycloak does not require SSL. This should really only be used in development when you are playing around with things.

all requests

Keycloak requires SSL for all IP addresses.

The SSL mode for each realm can be configured in the Keycloak admin console.

7.3.1. Enabling SSL/HTTPS for the Keycloak Server

If you are not using a reverse proxy or load balancer to handle HTTPS traffic for you, you’ll need to enable HTTPS for the Keycloak server. This involves

  1. Obtaining or generating a keystore that contains the private key and certificate for SSL/HTTP traffic

  2. Configuring the Keycloak server to use this keypair and certificate.

Creating the Certificate and Java Keystore

In order to allow HTTPS connections, you need to obtain a self signed or third-party signed certificate and import it into a Java keystore before you can enable HTTPS in the web container you are deploying the Keycloak Server to.

Self Signed Certificate

In development, you will probably not have a third party signed certificate available to test a Keycloak deployment so you’ll need to generate a self-signed one using the keytool utility that comes with the Java JDK.

$ keytool -genkey -alias localhost -keyalg RSA -keystore keycloak.jks -validity 10950
    Enter keystore password: secret
    Re-enter new password: secret
    What is your first and last name?
    [Unknown]:  localhost
    What is the name of your organizational unit?
    [Unknown]:  Keycloak
    What is the name of your organization?
    [Unknown]:  Red Hat
    What is the name of your City or Locality?
    [Unknown]:  Westford
    What is the name of your State or Province?
    [Unknown]:  MA
    What is the two-letter country code for this unit?
    [Unknown]:  US
    Is CN=localhost, OU=Keycloak, O=Test, L=Westford, ST=MA, C=US correct?
    [no]:  yes

You should answer What is your first and last name ? question with the DNS name of the machine you’re installing the server on. For testing purposes, localhost should be used. After executing this command, the keycloak.jks file will be generated in the same directory as you executed the keytool command in.

If you want a third-party signed certificate, but don’t have one, you can obtain one for free at cacert.org. You’ll have to do a little set up first before doing this though.

The first thing to do is generate a Certificate Request:

$ keytool -certreq -alias yourdomain -keystore keycloak.jks > keycloak.careq

Where yourdomain is a DNS name for which this certificate is generated for. Keytool generates the request:


Send this ca request to your CA. The CA will issue you a signed certificate and send it to you. Before you import your new cert, you must obtain and import the root certificate of the CA. You can download the cert from CA (ie.: root.crt) and import as follows:

$ keytool -import -keystore keycloak.jks -file root.crt -alias root

Last step is to import your new CA generated certificate to your keystore:

$ keytool -import -alias yourdomain -keystore keycloak.jks -file your-certificate.cer
Configure Keycloak to Use the Keystore

Now that you have a Java keystore with the appropriate certificates, you need to configure your Keycloak installation to use it. First step is to move the keystore file to the configuration/ directory of your deployment and to edit the standalone.xml, standalone-ha.xml or domain.xml file to use the keystore and enable HTTPS. (See operating mode).

In the standalone or domain configuration file, search for the security-realms element and add:

<security-realm name="UndertowRealm">
            <keystore path="keycloak.jks" relative-to="jboss.server.config.dir" keystore-password="secret" />

Find the element server name="default-server" (it’s a child element of subsystem xmlns="urn:jboss:domain:undertow:3.1") and add:

<subsystem xmlns="urn:jboss:domain:undertow:3.1">
   <buffer-cache name="default"/>
   <server name="default-server">
      <https-listener name="https" socket-binding="https" security-realm="UndertowRealm"/>

7.4. Outgoing HTTP Requests

The Keycloak server often needs to make non-browser HTTP requests to the applications and services it secures. The auth server manages these outgoing connections by maintaining an HTTP client connection pool. There are some things you’ll need to configure in standalone.xml, standalone-ha.xml, or domain.xml. The location of this file depends on your operating mode.

HTTP client Config example
<spi name="connectionsHttpClient">
    <provider name="default" enabled="true">
            <property name="connection-pool-size" value="256"/>

Possible configuration options are:


Timeout for establishing a socket connection.


If an outgoing request does not receive data for this amount of time, timeout the connection.


How many connections can be in the pool (128 by default).


How many connections can be pooled per host (64 by default).


Maximum connection time to live in milliseconds. Not set by default.


Maximum time the connection might stay idle in the connection pool (900 seconds by default). Will start background cleaner thread of Apache HTTP client. Set to -1 to disable this checking and the background thread.


true by default. When set to true, this will disable any cookie caching.


This is the file path to a Java keystore file. This keystore contains client certificate for two-way SSL.


Password for the client keystore. This is REQUIRED if client-keystore is set.


Password for the client’s key. This is REQUIRED if client-keystore is set.

7.4.1. Outgoing HTTPS Request Truststore

When Keycloak invokes on remote HTTPS endpoints, it has to validate the remote server’s certificate in order to ensure it is connecting to a trusted server. This is necessary in order to prevent man-in-the-middle attacks. The certificates of these remote server’s or the CA that signed these certificates must be put in a truststore. This truststore is managed by the Keycloak server.

The truststore is used when connecting securely to identity brokers, LDAP identity providers, when sending emails, and for backchannel communication with client applications.

By default, a truststore provider is not configured, and any https connections fall back to standard java truststore configuration as described in Java’s JSSE Reference Guide. If there is no trust establised, then these outgoing HTTPS requests will fail.

You can use keytool to create a new truststore file or add trusted host certificates to an existing one:

$ keytool -import -alias HOSTDOMAIN -keystore truststore.jks -file host-certificate.cer

The truststore is configured within the standalone.xml, standalone-ha.xml, or domain.xml file in your distribution. The location of this file depends on your operating mode. You can add your truststore configuration by using the following template:

<spi name="truststore">
    <provider name="file" enabled="true">
            <property name="file" value="path to your .jks file containing public certificates"/>
            <property name="password" value="password"/>
            <property name="hostname-verification-policy" value="WILDCARD"/>
            <property name="disabled" value="false"/>

Possible configuration options for this setting are:


The path to a Java keystore file. HTTPS requests need a way to verify the host of the server they are talking to. This is what the trustore does. The keystore contains one or more trusted host certificates or certificate authorities. This truststore file should only contain public certificates of your secured hosts. This is REQUIRED if disabled is not true.


Password for the truststore. This is REQUIRED if disabled is not true.


WILDCARD by default. For HTTPS requests, this verifies the hostname of the server’s certificate. ANY means that the hostname is not verified. WILDCARD Allows wildcards in subdomain names i.e. *.foo.com. STRICT CN must match hostname exactly.


If true (default value), truststore configuration will be ignored, and certificate checking will fall back to JSSE configuration as described. If set to false, you must configure file, and password for the truststore.

8. Clustering

This section covers configuring Keycloak to run in a cluster. There’s a number of things you have to do when setting up a cluster, specifically:

Picking an operation mode and configuring a shared database have been discussed earlier in this guide. In this chapter we’ll discuss setting up a load balancer and supplying a private network. We’ll also discuss some issues that you need to be aware of when booting up a host in the cluster.

It is possible to cluster Keycloak without IP Multicast, but this topic is beyond the scope of this guide. For more information, see JGroups chapter of the WildFly 10 Documentation.

The recommended network architecture for deploying Keycloak is to set up an HTTP/HTTPS load balancer on a public IP address that routes requests to Keycloak servers sitting on a private network. This isolates all clustering connections and provides a nice means of protecting the servers.

By default, there is nothing to prevent unauthorized nodes from joining the cluster and broadcasting multicast messages. This is why cluster nodes should be in a private network, with a firewall protecting them from outside attacks.

8.2. Clustering Example

Keycloak does come with an out of the box clustering demo that leverages domain mode. Review the Clustered Domain Example chapter for more details.

8.3. Setting Up a Load Balancer or Proxy

This section discusses a number of things you need to configure before you can put a reverse proxy or load balancer in front of your clustered Keycloak deployment. It also covers configuring the built in load balancer that was Clustered Domain Example.

8.3.1. Identifying Client IP Addresses

A few features in Keycloak rely on the fact that the remote address of the HTTP client connecting to the authentication server is the real IP address of the client machine. Examples include:

  • Event logs - a failed login attempt would be logged with the wrong source IP address

  • SSL required - if the SSL required is set to external (the default) it should require SSL for all external requests

  • Authentication flows - a custom authentication flow that uses the IP address to for example show OTP only for external requests

  • Dynamic Client Registration

This can be problematic when you have a reverse proxy or loadbalancer in front of your Keycloak authentication server. The usual setup is that you have a frontend proxy sitting on a public network that load balances and forwards requests to backend Keycloak server instances located in a private network. There is some extra configuration you have to do in this scenario so that the actual client IP address is forwarded to and processed by the Keycloak server instances. Specifically:

  • Configure your reverse proxy or loadbalancer to properly set X-Forwarded-For and X-Forwarded-Proto HTTP headers.

  • Configure your reverse proxy or loadbalancer to preserve the original 'Host' HTTP header.

  • Configure the authentication server to read the client’s IP address from X-Forwarded-For header.

Configuring your proxy to generate the X-Forwarded-For and X-Forwarded-Proto HTTP headers and preserving the original Host HTTP header is beyond the scope of this guide. Take extra precautions to ensure that the X-Forwared-For header is set by your proxy. If your proxy isn’t configured correctly, then rogue clients can set this header themselves and trick Keycloak into thinking the client is connecting from a different IP address than it actually is. This becomes really important if you are doing any black or white listing of IP addresses.

Beyond the proxy itself, there are a few things you need to configure on the Keycloak side of things. If your proxy is forwarding requests via the HTTP protocol, then you need to configure Keycloak to pull the client’s IP address from the X-Forwarded-For header rather than from the network packet. To do this, open up the profile configuration file (standalone.xml, standalone-ha.xml, or domain.xml depending on your operating mode) and look for the urn:jboss:domain:undertow:3.1 XML block.

X-Forwarded-For HTTP Config
<subsystem xmlns="urn:jboss:domain:undertow:3.1">
   <buffer-cache name="default"/>
   <server name="default-server">
      <ajp-listener name="ajp" socket-binding="ajp"/>
      <http-listener name="default" socket-binding="http" redirect-socket="https"

Add the proxy-address-forwarding attribute to the http-listener element. Set the value to true.

If your proxy is using the AJP protocol instead of HTTP to forward requests (i.e. Apache HTTPD + mod-cluster), then you have to configure things a little differently. Instead of modifying the http-listener, you need to add a filter to pull this information from the AJP packets.

X-Forwarded-For AJP Config
<subsystem xmlns="urn:jboss:domain:undertow:3.1">
     <buffer-cache name="default"/>
     <server name="default-server">
         <ajp-listener name="ajp" socket-binding="ajp"/>
         <http-listener name="default" socket-binding="http" redirect-socket="https"/>
         <host name="default-host" alias="localhost">
             <filter-ref name="proxy-peer"/>
         <filter name="proxy-peer"
                 module="io.undertow.core" />

8.3.2. Enable HTTPS/SSL with a Reverse Proxy

Assuming that your reverse proxy doesn’t use port 8443 for SSL you also need to configure what port HTTPS traffic is redirected to.

<subsystem xmlns="urn:jboss:domain:undertow:3.1">
    <http-listener name="default" socket-binding="http"
        proxy-address-forwarding="true" redirect-socket="proxy-https"/>

Add the redirect-socket attribute to the http-listener element. The value should be proxy-https which points to a socket binding you also need to define.

Then add a new socket-binding element to the socket-binding-group element:

<socket-binding-group name="standard-sockets" default-interface="public"
    <socket-binding name="proxy-https" port="443"/>

8.3.3. Verify Configuration

You can verify the reverse proxy or load balancer configuration by opening the path /auth/realms/master/.well-known/openid-configuration through the reverse proxy. For example if the reverse proxy address is https://acme.com/ then open the URL https://acme.com/auth/realms/master/.well-known/openid-configuration. This will show a JSON document listing a number of endpoints for Keycloak. Make sure the endpoints starts with the address (scheme, domain and port) of your reverse proxy or load balancer. By doing this you make sure that Keycloak is using the correct endpoint.

You should also verify that Keycloak sees the correct source IP address for requests. Do check this you can try to login to the admin console with an invalid username and/or password. This should show a warning in the server log something like this:

08:14:21,287 WARN  XNIO-1 task-45 [org.keycloak.events] type=LOGIN_ERROR, realmId=master, clientId=security-admin-console, userId=8f20d7ba-4974-4811-a695-242c8fbd1bf8, ipAddress=X.X.X.X, error=invalid_user_credentials, auth_method=openid-connect, auth_type=code, redirect_uri=http://localhost:8080/auth/admin/master/console/?redirect_fragment=%2Frealms%2Fmaster%2Fevents-settings, code_id=a3d48b67-a439-4546-b992-e93311d6493e, username=admin

Check that the value of ipAddress is the IP address of the machine you tried to login with and not the IP address of the reverse proxy or load balancer.

8.3.4. Using the Built-In Load Balancer

This section covers configuring the built in load balancer that is discussed in the Clustered Domain Example.

The Clustered Domain Example is only designed to run on one machine. To bring up a slave on another host, you’ll need to

  1. Edit the domain.xml file to point to your new host slave

  2. Copy the server distribution. You don’t need the domain.xml, host.xml, or host-master.xml files. Nor do you need the standalone/ directory.

  3. Edit the host-slave.xml file to change the bind addresses used or override them on the command line

Register a New Host With Load Balancer

Let’s look first at registering the new host slave with the load balancer configuration in domain.xml. Open this file and go to the undertow configuration in the load-balancer profile. Add a new host definition called remote-host3 within the reverse-proxy XML block.

domain.xml reverse-proxy config
<subsystem xmlns="urn:jboss:domain:undertow:3.1">
      <reverse-proxy name="lb-handler">
         <host name="host1" outbound-socket-binding="remote-host1" scheme="ajp" path="/" instance-id="myroute1"/>
         <host name="host2" outbound-socket-binding="remote-host2" scheme="ajp" path="/" instance-id="myroute2"/>
         <host name="remote-host3" outbound-socket-binding="remote-host3" scheme="ajp" path="/" instance-id="myroute3"/>

The output-socket-binding is a logical name pointing to a socket-binding configured later in the domain.xml file. the instance-id attribute must also be unique to the new host as this value is used by a cookie to enable sticky sessions when load balancing.

Next go down to the load-balancer-sockets socket-binding-group and add the outbound-socket-binding for remote-host3. This new binding needs to point to the host and port of the new host.

domain.xml outbound-socket-binding
<socket-binding-group name="load-balancer-sockets" default-interface="public">
    <outbound-socket-binding name="remote-host1">
        <remote-destination host="localhost" port="8159"/>
    <outbound-socket-binding name="remote-host2">
        <remote-destination host="localhost" port="8259"/>
    <outbound-socket-binding name="remote-host3">
        <remote-destination host="" port="8259"/>
Master Bind Addresses

Next thing you’ll have to do is to change the public and management bind addresses for the master host. Either edit the domain.xml file as discussed in the Bind Addresses chapter or specify these bind addresses on the command line as follows:

$ domain.sh --host-config=host-master.xml -Djboss.bind.address= -Djboss.bind.address.management=
Host Slave Bind Addresses

Next you’ll have to change the public, management, and domain controller bind addresses (jboss.domain.master-address). Either edit the host-slave.xml file or specify them on the command line as follows:

$ domain.sh --host-config=host-slave.xml

The values of jboss.bind.address and jboss.bind.addres.management pertain to the host slave’s IP address. The value of jboss.domain.master.address need to be the IP address of the domain controller which is the management address of the master host.

8.3.5. Configuring Other Load Balancers

See the load balancing section in the WildFly 10 Documentation for information how to use other software-based load balancers.

8.4. Sticky sessions

Typical cluster deployment consists of the load balancer (reverse proxy) and 2 or more Keycloak servers on private network. For performance purposes, it may be useful if load balancer forwards all requests related to particular browser session to the same Keycloak backend node.

The reason is, that Keycloak is using infinispan distributed cache under the covers for save data related to current authentication session and user session. The Infinispan distributed caches are configured with one owner by default. That means that particular session is saved just on one cluster node and the other nodes need to lookup the session remotely if they want to access it.

For example if authentication session with ID 123 is saved in the infinispan cache on node1, and then node2 needs to lookup this session, it needs to send the request to node1 over the network to return the particular session entity.

It is beneficial if particular session entity is always available locally, which can be done with the help of sticky sessions. The workflow in the cluster environment with the public frontend load balancer and two backend Keycloak nodes can be like this:

  • User sends initial request to see the Keycloak login screen

  • This request is served by the frontend load balancer, which forwards it to some random node (eg. node1). Strictly said, the node doesn’t need to be random, but can be chosen according to some other criterias (client IP address etc). It all depends on the implementation and configuration of underlying load balancer (reverse proxy).

  • Keycloak creates authentication session with random ID (eg. 123) and saves it to the Infinispan cache.

  • Infinispan distributed cache assigns the primary owner of the session based on the hash of session ID. See Infinispan documentation for more details around this. Let’s assume that infinispan assigned node2 to be the owner of this session.

  • Keycloak creates the cookie AUTH_SESSION_ID with the format like <session-id>.<owner-node-id> . In our example case, it will be 123.node2 .

  • Response is returned to the user with the Keycloak login screen and the AUTH_SESSION_ID cookie in the browser

From this point, it is beneficial if load balancer forwards all the next requests to the node2 as this is the node, who is owner of the authentication session with ID 123 and hence Infinispan can lookup this session locally. After authentication is finished, the authentication session is converted to user session, which will be also saved on node2 because it has same ID 123 .

The sticky session is not mandatory for the cluster setup, however it is good for performance for the reasons mentioned above. You need to configure your loadbalancer to sticky over the AUTH_SESSION_ID cookie. How exactly do this is dependent on your loadbalancer.

Some loadbalancers can be configured to add the route information by themselves instead of rely on the backend Keycloak node. However adding the route by the Keycloak is more clever as Keycloak knows, who is the owner of particular session entity and can route it to that node, which is not necessarily the local node. We plan to support the setup where the route info won’t be added to AUTH_SESSION_ID cookie by the Keycloak server, but instead by the load balancer. However adding the cookie by Keycloak would be still the preferred option.

8.4.1. Example cluster setup with mod_cluster

In the example, we will use Mod Cluster as load balancer. One of the key features of mod cluster is, that there is not much configuration on the load balancer side. Instead it requires support on the backend node side. Backend nodes communicate with the load balancer through the dedicated protocol called MCMP and they notify loadbalancer about various events (eg. node joined or left cluster, new application was deployed etc).

Example setup will consist of the one WildFly 10 load balancer node and two Keycloak nodes.

Clustering example require MULTICAST to be enabled on machine’s loopback network interface. This can be done by running the following commands under root privileges (on linux):

route add -net netmask dev lo
ifconfig lo multicast
Load Balancer Configuration

Unzip the WildFly 10 server somewhere. Assumption is location EAP_LB

Edit EAP_LB/standalone/configuration/standalone.xml file. In the undertow subsystem add the mod_cluster configuration under filters like this:

<subsystem xmlns="urn:jboss:domain:undertow:4.0">
  <mod-cluster name="modcluster" advertise-socket-binding="modcluster"
      management-socket-binding="http" enable-http2="true"/>

and filter-ref under default-host like this:

<host name="default-host" alias="localhost">
    <filter-ref name="modcluster"/>

Then under socket-binding-group add this group:

<socket-binding name="modcluster" port="0"

Save the file and run the server:

cd $WILDFLY_LB/bin
Backend node configuration

Unzip the Keycloak server distribution to some location. Assuming location is RHSSO_NODE1 .

Edit RHSSO_NODE1/standalone/configuration/standalone-ha.xml and configure datasource against the shared database. See Database chapter for more details.

In the undertow subsystem, add the session-config under the servlet-container element:

<servlet-container name="default">
    <session-cookie name="AUTH_SESSION_ID" http-only="true" />

Then you can configure proxy-address-forwarding as described in the chapter Load Balancer . Note that mod_cluster uses AJP connector by default, so you need to configure that one.

That’s all as mod_cluster is already configured.

The node name of the Keycloak can be detected automatically based on the hostname of current server. However for more fine grained control, it is recommended to use system property jboss.node.name to specify the node name directly. It is especially useful in case that you test with 2 backend nodes on same physical server etc. So you can run the startup command like this:

./standalone.sh -c standalone-ha.xml -Djboss.socket.binding.port-offset=100 -Djboss.node.name=node1

Configure the second backend server in same way and run with different port offset and node name.

./standalone.sh -c standalone-ha.xml -Djboss.socket.binding.port-offset=200 -Djboss.node.name=node2

Access the server on http://localhost:8080/auth . Creation of admin user is possible just from local address and without load balancer (proxy) access, so you first need to access backend node directly on http://localhost:8180/auth to create admin user.

8.5. Multicast Network Setup

Out of the box clustering support needs IP Multicast. Multicast is a network broadcast protocol. This protocol is used at boot time to discover and join the cluster. It is also used to broadcast messages for the replication and invalidation of distributed caches used by Keycloak.

The clustering subsystem for Keycloak runs on the JGroups stack. Out of the box, the bind addresses for clustering are bound to a private network interface with as default IP address. You have to edit your the standalone-ha.xml or domain.xml sections discussed in the Bind Address chapter.

private network config
        <interface name="private">
            <inet-address value="${jboss.bind.address.private:}"/>
    <socket-binding-group name="standard-sockets" default-interface="public" port-offset="${jboss.socket.binding.port-offset:0}">
        <socket-binding name="jgroups-mping" interface="private" port="0" multicast-address="${jboss.default.multicast.address:}" multicast-port="45700"/>
        <socket-binding name="jgroups-tcp" interface="private" port="7600"/>
        <socket-binding name="jgroups-tcp-fd" interface="private" port="57600"/>
        <socket-binding name="jgroups-udp" interface="private" port="55200" multicast-address="${jboss.default.multicast.address:}" multicast-port="45688"/>
        <socket-binding name="jgroups-udp-fd" interface="private" port="54200"/>
        <socket-binding name="modcluster" port="0" multicast-address="" multicast-port="23364"/>

Things you’ll want to configure are the jboss.bind.address.private and jboss.default.multicast.address as well as the ports of the services on the clustering stack.

It is possible to cluster Keycloak without IP Multicast, but this topic is beyond the scope of this guide. For more information, see JGroups in the WildFly 10 Documentation.

8.6. Securing Cluster Communication

When cluster nodes are isolated on a private network it requires access to the private network to be able to join a cluster or to view communication in the cluster. In addition you can also enable authentication and encryption for cluster communication. As long as your private network is secure it is not necessary to enable authentication and encryption. Keycloak does not send very sensitive information on the cluster in either case.

If you want to enable authentication and encryption for clustering communication see Securing a Cluster in the JBoss EAP Configuration Guide.

8.7. Serialized Cluster Startup

Keycloak cluster nodes are allowed to boot concurrenty. When Keycloak server instance boots up it may do some database migration, importing, or first time initializations. A DB lock is used to prevent start actions from conflicting with one another when cluster nodes boot up concurrently.

By default, the maximum timeout for this lock is 900 seconds. If a node is waiting on this lock for more than the timeout it will fail to boot. Typically you won’t need to increase/decrease the default value, but just in case it’s possible to configure it in standalone.xml, standalone-ha.xml, or domain.xml file in your distribution. The location of this file depends on your operating mode.

<spi name="dblock">
    <provider name="jpa" enabled="true">
            <property name="lockWaitTimeout" value="900"/>

8.8. Booting the Cluster

Booting Keycloak in a cluster depends on your operating mode

Standalone Mode
$ bin/standalone.sh --server-config=standalone-ha.xml
Domain Mode
$ bin/domain.sh --host-config=host-master.xml
$ bin/domain.sh --host-config=host-slave.xml

8.9. Troubleshooting

Note that when you run cluster, you should see message similar to this in the log of both cluster nodes:

INFO  [org.infinispan.remoting.transport.jgroups.JGroupsTransport] (Incoming-10,shared=udp)
ISPN000094: Received new cluster view: [node1/keycloak|1] (2) [node1/keycloak, node2/keycloak]

If you see just one node mentioned, it’s possible that your cluster hosts are not joined together.

Usually it’s best practice to have your cluster nodes on private network without firewall for communication among them. Firewall could be enabled just on public access point to your network instead. If for some reason you still need to have firewall enabled on cluster nodes, you will need to open some ports. Default values are UDP port 55200 and multicast port 45688 with multicast address Note that you may need more ports opened if you want to enable additional features like diagnostics for your JGroups stack. Keycloak delegates most of the clustering work to Infinispan/JGroups. For more information, see JGroups in the WildFly 10 Documentation.

9. Server Cache Configuration

Keycloak has two types of caches. One type of cache sits in front of the database to decrease load on the DB and to increase overall response times by keeping data in memory. Realm, client, role, and user metadata is kept in this type of cache. This cache is a local cache. Local caches do not use replication even if you are in the cluster with more Keycloak servers. Instead, they only keep copies locally and if the entry is updated an invalidation message is sent to the rest of the cluster and the entry is evicted. There is separate replicated cache work, which task is to send the invalidation messages to the whole cluster about what entries should be evicted from local caches. This greatly reduces network traffic, makes things efficient, and avoids transmitting sensitive metadata over the wire.

The second type of cache handles managing user sessions, offline tokens, and keeping track of login failures so that the server can detect password phishing and other attacks. The data held in these caches is temporary, in memory only, but is possibly replicated across the cluster.

This chapter discusses some configuration options for these caches for both clustered a non-clustered deployments.

More advanced configuration of these caches can be found in the Infinispan section of the WildFly 10 Documentation.

9.1. Eviction and Expiration

There are multiple different caches configured for Keycloak. There is a realm cache that holds information about secured applications, general security data, and configuration options. There is also a user cache that contains user metadata. Both caches default to a maximum of 10000 entries and use a least recently used eviction strategy. Each of them is also tied to an object revisions cache that controls eviction in a clustered setup. This cache is created implicitely and has twice the configured size. There are also separate caches for user sessions, offline tokens, and login failures. These caches are unbounded in size as well.

The eviction policy and max entries for these caches can be configured in the standalone.xml, standalone-ha.xml, or domain.xml depending on your operating mode.

<subsystem xmlns="urn:jboss:domain:infinispan:4.0">
    <cache-container name="keycloak" jndi-name="infinispan/Keycloak">
        <local-cache name="realms">
            <eviction max-entries="10000" strategy="LRU"/>
        <local-cache name="users">
            <eviction max-entries="10000" strategy="LRU"/>
        <local-cache name="sessions"/>
        <local-cache name="offlineSessions"/>
        <local-cache name="loginFailures"/>
        <local-cache name="work"/>
        <local-cache name="authorization">
           <eviction strategy="LRU" max-entries="100"/>
        <local-cache name="keys">
            <eviction strategy="LRU" max-entries="1000"/>
            <expiration max-idle="3600000"/>
<subsystem xmlns="urn:jboss:domain:infinispan:4.0">
    <cache-container name="keycloak" jndi-name="infinispan/Keycloak">
        <transport lock-timeout="60000"/>
        <local-cache name="realms">
            <eviction max-entries="10000" strategy="LRU"/>
        <local-cache name="users">
            <eviction max-entries="10000" strategy="LRU"/>
        <distributed-cache name="sessions" mode="SYNC" owners="1"/>
        <distributed-cache name="offlineSessions" mode="SYNC" owners="1"/>
        <distributed-cache name="loginFailures" mode="SYNC" owners="1"/>
        <distributed-cache name="authorization" mode="SYNC" owners="1"/>
        <replicated-cache name="work" mode="SYNC"/>
        <local-cache name="keys">
            <eviction max-entries="1000" strategy="LRU"/>
            <expiration max-idle="3600000"/>

To limit or expand the number of allowed entries simply add or edit the eviction element or the expiration element of particular cache configuration.

9.2. Replication and Failover

The sessions, authenticationSessions, offlineSessions and loginFailures caches are the only caches that may perform replication. Entries are not replicated to every single node, but instead one or more nodes is chosen as an owner of that data. If a node is not the owner of a specific cache entry it queries the cluster to obtain it. What this means for failover is that if all the nodes that own a piece of data go down, that data is lost forever. By default, Keycloak only specifies one owner for data. So if that one node goes down that data is lost. This usually means that users will be logged out and will have to login again.

You can change the number of nodes that replicate a piece of data by change the owners attribute in the distributed-cache declaration.

<subsystem xmlns="urn:jboss:domain:infinispan:4.0">
   <cache-container name="keycloak" jndi-name="infinispan/Keycloak">
       <distributed-cache name="sessions" mode="SYNC" owners="2"/>

Here we’ve changed it so at least two nodes will replicate one specific user login session.

The number of owners recommended is really dependent on your deployment. If you do not care if users are logged out when a node goes down, then one owner is good enough and you will avoid replication.

9.3. Disabling Caching

To disable the realm or user cache, you must edit the standalone.xml, standalone-ha.xml, or domain.xml file in your distribution. The location of this file depends on your operating mode. Here’s what the config looks like initially.

    <spi name="userCache">
        <provider name="default" enabled="true"/>

    <spi name="realmCache">
        <provider name="default" enabled="true"/>

To disable the cache set the enabled attribute to false for the cache you want to disable. You must reboot your server for this change to take effect.

9.4. Clearing Caches at Runtime

To clear the realm or user cache, go to the Keycloak admin console Realm Settings→Cache Config page. On this page you can clear the realm cache, the user cache or cache of external public keys.

The cache will be cleared for all realms!

10. Keycloak Security Proxy

Keycloak has an HTTP(S) proxy that you can put in front of web applications and services where it is not possible to install the Keycloak adapter. You can set up URL filters so that certain URLs are secured either by browser login and/or bearer token authentication. You can also define role constraints for URL patterns within your applications.

10.1. Proxy Install and Run

Download the Keycloak proxy distribution from the Keycloak download pages and unzip it.

$ unzip keycloak-proxy-dist.zip

To run it you must have a proxy config file (which we’ll discuss in a moment).

$ java -jar bin/launcher.jar [your-config.json]

If you do not specify a path to the proxy config file, the launcher will look in the current working directory for the file named proxy.json

10.2. Proxy Configuration

Here’s an example configuration file.

    "target-url": "http://localhost:8082",
    "send-access-token": true,
    "bind-address": "localhost",
    "http-port": "8080",
    "https-port": "8443",
    "keystore": "classpath:ssl.jks",
    "keystore-password": "password",
    "key-password": "password",
    "applications": [
            "base-path": "/customer-portal",
            "error-page": "/error.html",
            "adapter-config": {
                "realm": "demo",
                "resource": "customer-portal",
                "realm-public-key": "MIGfMA0GCSqGSIb",
                "auth-server-url": "http://localhost:8081/auth",
                "ssl-required" : "external",
                "principal-attribute": "name",
                "credentials": {
                    "secret": "password"
            "constraints": [
                    "pattern": "/users/*",
                    "roles-allowed": [
                    "pattern": "/admins/*",
                    "roles-allowed": [
                    "pattern": "/users/permit",
                    "permit": true
                    "pattern": "/users/deny",
                    "deny": true

10.2.1. Basic Config

The basic configuration options for the server are as follows:


The URL this server is proxying REQUIRED..


Boolean flag. If true, this will send the access token via the KEYCLOAK_ACCESS_TOKEN header to the proxied server. OPTIONAL.. Default is false.


DNS name or IP address to bind the proxy server’s sockets to. OPTIONAL.. The default value is localhost


Port to listen for HTTP requests. If you do not specify this value, then the proxy will not listen for regular HTTP requests. OPTIONAL..


Port to listen for HTTPS requests. If you do not specify this value, then the proxy will not listen for HTTPS requests. OPTIONAL..


Path to a Java keystore file that contains private key and certificate for the server to be able to handle HTTPS requests. Can be a file path, or, if you prefix it with classpath: it will look for this file in the classpath. OPTIONAL.. If you have enabled HTTPS, but have not defined a keystore, the proxy will auto-generate a self-signed certificate and use that.


HTTP server socket buffer size. Usually the default is good enough. OPTIONAL..


HTTP server socket buffers per region. Usually the default is good enough. OPTIONAL..


Number of threads to handle IO. Usually default is good enough. OPTIONAL.. The default is the number of available processors * 2.


Number of threads to handle requests. Usually the default is good enough. OPTIONAL.. The default is the number of available processors * 16.

10.3. Application Config

Next under the applications array attribute, you can define one or more applications per host you are proxying.


The base context root for the application. Must start with '/' REQUIRED..


If the proxy has an error, it will display the target application’s error page relative URL OPTIONAL.. This is a relative path to the base-path. In the example above it would be /customer-portal/error.html.


REQUIRED.. Same configuration as any other Keycloak adapter.

10.3.1. Constraint Config

Next under each application you can define one or more constraints in the constraints array attribute. A constraint defines a URL pattern relative to the base-path. You can deny, permit, or require authentication for a specific URL pattern. You can specify roles allowed for that path as well. More specific constraints will take precedence over more general ones.


URL pattern to match relative to the base-path of the application. Must start with '/' REQUIRED. You may only have one wildcard and it must come at the end of the pattern.

  • Valid: /foo/bar/* and /foo/*.txt

  • Not valid: /*/foo/*.


Array of strings of roles allowed to access this url pattern. OPTIONAL..


Array of strings of HTTP methods that will exclusively match this pattern and HTTP request. OPTIONAL..


Array of strings of HTTP methods that will be ignored when match this pattern. OPTIONAL..


Deny all access to this URL pattern. OPTIONAL..


Permit all access without requiring authentication or a role mapping. OPTIONAL..


Permit all access, but inject the headers, if user is already authenticated.OPTIONAL..


Require authentication for this pattern, but no role mapping. OPTIONAL..

10.3.2. Header Names Config

Next under the list of applications you can override the defaults for the names of the header fields injected by the proxy (see Keycloak Identity Headers). This mapping is optional.











10.4. Keycloak Identity Headers

When forwarding requests to the proxied server, Keycloak Proxy will set some additional headers with values from the OIDC identity token it received for authentication.


User id. Corresponds to JWT sub and will be the user id Keycloak uses to store this user.


Username. Corresponds to JWT preferred_username


Email address of user if set.


Full name of user if set.


Send the access token in this header if the proxy was configured to send it. This token can be used to make bearer token requests. Header field names can be configured using a map of header-names in configuration file:

    "header-names" {
        "keycloak-subject": "MY_SUBJECT"

1. Tracked as https://issues.jboss.org/browse/KEYCLOAK-3873