Package net.javacrumbs.shedlock.provider.hazelcast4

Class HazelcastLockProvider

java.lang.Object

net.javacrumbs.shedlock.provider.hazelcast4.HazelcastLockProvider

All Implemented Interfaces:

LockProvider

public class HazelcastLockProvider
extends Object
implements LockProvider

HazelcastLockProvider.

Implementation of LockProvider using Hazelcast for storing and sharing lock information and mechanisms between a cluster's members

Below, the mechanisms : - The Lock, an instance of HazelcastLock, is obtained / created when : -- the lock is not already locked by other process (lock - referenced by its name - is not present in the Hazelcast locks store OR unlockable) -- the lock is expired : Instant.now() > HazelcastLock.timeToLive where unlockTime have by default the same value of HazelcastLock.lockAtMostUntil and can have the value of HazelcastLock.lockAtLeastUntil if unlock action is used --- expired object is removed -- the lock is owned by not available member of Hazelcast cluster member --- no owner object is removed - Unlock action : -- removes lock object when HazelcastLock.lockAtLeastUntil is not come -- override value of HazelcastLock.timeToLive with HazelcastLock.lockAtLeastUntil (its default value is the same of HazelcastLock.lockAtLeastUntil

Constructor Summary

Constructors

Constructor	Description
HazelcastLockProvider(com.hazelcast.core.HazelcastInstance hazelcastInstance)	Instantiate the provider.
HazelcastLockProvider(com.hazelcast.core.HazelcastInstance hazelcastInstance, String lockStoreKey)	Instantiate the provider.
HazelcastLockProvider(com.hazelcast.core.HazelcastInstance hazelcastInstance, String lockStoreKey, Duration lockLeaseTime)	Instantiate the provider.

Method Summary

Modifier and Type	Method	Description
Optional<SimpleLock>	lock(LockConfiguration lockConfiguration)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

HazelcastLockProvider

public HazelcastLockProvider(com.hazelcast.core.HazelcastInstance hazelcastInstance)

Instantiate the provider.

Parameters:

hazelcastInstance - The Hazelcast engine used by the application.

HazelcastLockProvider

public HazelcastLockProvider(com.hazelcast.core.HazelcastInstance hazelcastInstance,
 String lockStoreKey)

Instantiate the provider.

Parameters:

hazelcastInstance - The Hazelcast engine used by the application

lockStoreKey - The key where the locks are stored (by default LOCK_STORE_KEY_DEFAULT).

HazelcastLockProvider

public HazelcastLockProvider(com.hazelcast.core.HazelcastInstance hazelcastInstance,
 String lockStoreKey,
 Duration lockLeaseTime)

Instantiate the provider.

Parameters:

hazelcastInstance - The com.hazelcast.core.Hazelcast engine used by the application

lockStoreKey - The key where the locks are stored (by default LOCK_STORE_KEY_DEFAULT).

lockLeaseTime - When lock is being obtained there is a Hazelcast lock used to make it thread-safe. This lock should be released quite fast but if the process dies while holding the lock, it is held forever. lockLeaseTime is used as a safety-net for such situations.

Method Details

lock

public Optional<SimpleLock> lock(LockConfiguration lockConfiguration)

Specified by:

lock in interface LockProvider