org.keycloak.models.dblock

Interface DBLockProvider

All Superinterfaces:

Provider

All Known Implementing Classes:

LiquibaseDBLockProvider

public interface DBLockProvider
extends Provider

Global database lock to ensure that some actions in DB can be done just be one cluster node at a time.

There are different namespaces that can be locked. The same DBLockProvider (same session in keycloack) can only be used to lock one namespace, a second attempt will throw a RuntimeException. The hasLock method returns the local namespace locked by this provider.

Different DBLockProvider instances can be used to lock in different threads. Note that the DBLockProvider is associated to the session (so in order to have different lock providers different sessions are needed).

Author:

Marek Posolda

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	DBLockProvider.Namespace Lock namespace to have different lock types or contexts.

Method Summary

Modifier and Type	Method and Description
void	destroyLockInfo() Will destroy whole state of DB lock (drop table/collection to track locking).
DBLockProvider.Namespace	getCurrentLock() Returns the current provider namespace locked or null
void	releaseLock() Release previously acquired lock by this provider.
boolean	supportsForcedUnlock()
void	waitForLock(DBLockProvider.Namespace lock) Try to retrieve DB lock or wait if retrieve was unsuccessful.

Methods inherited from interface org.keycloak.provider.Provider

close

Method Detail

waitForLock

void waitForLock(DBLockProvider.Namespace lock)

Try to retrieve DB lock or wait if retrieve was unsuccessful. Throw exception if lock can't be retrieved within specified timeout (900 seconds by default) Throw exception if a different namespace has already been locked by this provider.

Parameters:

lock - The namespace to lock

releaseLock

void releaseLock()

Release previously acquired lock by this provider.

getCurrentLock

DBLockProvider.Namespace getCurrentLock()

Returns the current provider namespace locked or null

Returns:

The namespace locked or null if there is no lock

supportsForcedUnlock

boolean supportsForcedUnlock()

Returns:

true if provider supports forced unlock at startup

destroyLockInfo

void destroyLockInfo()

Will destroy whole state of DB lock (drop table/collection to track locking).