DBLockProvider (Keycloak Docs Distribution 21.1.1 API)

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 Description

static class DBLockProvider.Namespace
Lock namespace to have different lock types or contexts.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	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).