jedis-lock

Jedis Lock Config

JedisLockConfigs lockConfig = JedisLockConfigs.builder()
    .keyTTL(5000) // Lock key expiration time (mils). Default 30000
    .updateTTLScheduleTime(1000) // Watchdog schedule time (mils). Default 10000
    .multiLockWaitingTime(300) // Internal lock waiting time. Using for RedLock
    .build();

JedisLockManager (Singleton)

If the used Redis configuration is Pool or JedisCluster, single-reentrant lock is used by default. If the input configuration is List of Pools, red-lock is used for locking.

• Single Reentrant Lock

For single Redis node (Single Pool)

JedisPoolConfig poolConfig = new JedisPoolConfig();
poolConfig.setMinIdle(10);
poolConfig.setMaxIdle(50);
poolConfig.setMaxTotal(100);
poolConfig.setMaxWaitMillis(1000);
	
JedisLockManager lockManager = new JedisLockManager(new JedisPool(poolConfig, "127.0.0.1", 6379), lockConfig);

For cluster Redis (JedisCluster)

JedisPoolConfig poolConfig = new JedisPoolConfig();
poolConfig.setMinIdle(10);
poolConfig.setMaxIdle(50);
poolConfig.setMaxTotal(100);
poolConfig.setMaxWaitMillis(1000);

JedisLockManager lockManager = new JedisLockManager(new JedisCluster(new HostAndPort("127.0.0.1", 6379), poolConfig), lockConfig);

• Red Lock

Requires number of redis nodes greater or equals 3 (should be odd number) and these nodes must be deployed independently, with no state between each node, and no master-slave copy or cluster management.

JedisPoolConfig poolConfig = new JedisPoolConfig();
poolConfig.setMinIdle(10);
poolConfig.setMaxIdle(50);
poolConfig.setMaxTotal(100);
poolConfig.setMaxWaitMillis(1000);

JedisLockManager lockManager = new JedisLockManager(Arrays.asList(
    new JedisPool(poolConfig, "127.0.0.1", 6379),
    new JedisPool(poolConfig, "127.0.0.1", 6380),
    new JedisPool(poolConfig, "127.0.0.1", 6381)), lockConfig);

API Usage

• Lock Object

JedisLock lock = lockManager.getLock("lock_name");

• Operations

/*
 * Acquire the lock. If lock cannot be acquired, the thread will be blocked (Blocking lock)
 */

try {
    lock.lock();
    //...
} catch () {
    //...
} finally {
    lock.unlock(); //Release lock
}

/*
 * Try to acquire the lock, and return immediately if unable to acquire the lock (Non-blocking lock)
 */

if (lock.tryLock()) {
    try {
	//...
    } catch () {
        //...
    } finally {
        lock.unlock(); //Release lock
    }
}

/*
 * Try to acquire lock with maximum waiting time
 */

if (lock.tryLock(1, TimeUnit.SECONDS)) {
    try {
	//...
    } catch () {
        //...
    } finally {
        lock.unlock(); //Release lock
    }
}

/*
 * Force unlocking
 */

lock.forceUnlock();

SpringBoot Integration

Beans Configuration

@ComponentScan("com.github.example.spring.jedis.lock")
@Configuration
class JedisLockConfiguration {

    @Bean
    public JedisPool jedisPool() {
        JedisPoolConfig poolConfig = new JedisPoolConfig();
        poolConfig.setMinIdle(10);
        poolConfig.setMaxIdle(50);
        poolConfig.setMaxTotal(100);
        poolConfig.setMaxWaitMillis(1000);
        return new JedisPool(poolConfig, "127.0.0.1", 6379);
    }

    @Bean
    public JedisLockConfigs jedisLockConfigs() {
        return JedisLockConfigs.builder()
            .keyTTL(5000) // Lock key expiration time (mils). Default 30000
            .updateTTLScheduleTime(1000) // Watchdog schedule time (mils). Default 10000
            .multiLockWaitingTime(300) // Internal lock waiting time. Using for RedLock
            .build();
    }

    @Bean
    public JedisLockManager jedisLockManager() {
        return new JedisLockManager(jedisPool(), jedisLockConfigs());
    }
}

Annotation Usage

@DistributedLock(keyFormat = "lockName", method = DistributedLock.Method.LOCK)
public void foo() {}

@DistributedLock(keyType = DistributedLock.KeyType.ARGUMENTS, keyFormat = "lockName|%s", method = DistributedLock.Method.TRY_LOCK)
public void foo(Object... args) {}

@DistributedLock(keyType = DistributedLock.KeyType.ARGUMENTS, keyFormat = "lockName|%s", method = DistributedLock.Method.TRY_LOCK, waitTime = 1000L, timeUnit = TimeUnit.MILLISECONDS)
public void foo(Object... args) {}

• keyType: Lock key type (CONSTANT | ARGUMENTS)
• keyFormat: Lock key format. (Using method parameters as arguments if keyType is ARGUMENTS)
• method: LOCK | TRY_LOCK. (It will throw exception in TRY_LOCK case if lock cannot be acquired)
• waitTime: Try lock with waiting time
• timeUnit: Time unit of waitTime