public final class RedisLockRegistry extends Object implements LockRegistry
LockRegistry providing a distributed lock using Redis.
Locks are stored under the key registryKey:lockKey. Locks expire after
(default 60) seconds. Threads unlocking an
expired lock will get an IllegalStateException. This should be
considered as a critical error because it is possible the protected
resources were compromised.
Locks are reentrant.
However, locks are scoped by the registry; a lock from a different registry with the same key (even if the registry uses the same 'registryKey') are different locks, and the second cannot be acquired by the same thread while the first is locked.
Note: This is not intended for low latency applications. It is intended for resource locking across multiple JVMs. When a lock is released by a remote system, waiting threads may take up to 100ms to acquire the lock. A more performant version would need to get notifications from the Redis stores of key changes. This is currently only available using the SYNC command.
This limitation will usually not apply when a lock is released within this registry,
unless another system takes the lock after the local lock is acquired here.
A DefaultLockRegistry is used internally to achieve this optimization.
Conditions are not supported.
| Constructor and Description |
|---|
RedisLockRegistry(RedisConnectionFactory connectionFactory,
String registryKey)
Constructs a lock registry with the default (60 second) lock expiration.
|
RedisLockRegistry(RedisConnectionFactory connectionFactory,
String registryKey,
long expireAfter)
Constructs a lock registry with the supplied lock expiration.
|
public RedisLockRegistry(RedisConnectionFactory connectionFactory, String registryKey)
connectionFactory - The connection factory.registryKey - The key prefix for locks.public RedisLockRegistry(RedisConnectionFactory connectionFactory, String registryKey, long expireAfter)
connectionFactory - The connection factory.registryKey - The key prefix for locks.expireAfter - The expiration in milliseconds.public Lock obtain(Object lockKey)
LockRegistryobtain in interface LockRegistrylockKey - The object with which the lock is associated.public Collection<Lock> listLocks()