Two different threads have reported acquiring a lock with the same key at the same time

[OuDale]

Redisson version :

<dependency>
    <groupId>org.redisson</groupId>
    <artifactId>redisson-spring-boot-starter</artifactId>
    <version>3.17.4</version>
</dependency>

Here is my code:

private void generate() {
        RLock lock = redisson.getLock(key);
        try {
            String threadName = Thread.currentThread().getName();
            boolean locked = lock.tryLock();
            if (locked && shouldGenerateTask() {
                log.info("locked by key:{} with thread：{}", key, threadName);
                saveTask();
            }
        } catch (Exception e) {
            Thread.currentThread().interrupt();
        } finally {
            if (lock.isHeldByCurrentThread()) {
                lock.unlock();
            }
        }
    }

2024-01-12T12:00:07.514288425Z 2024-01-12 12:00:07.514 INFO 7 --- [ XNIO-1 task-4] .s.p.a.t.c.h.i.test : locked by key:App:Procurement:PENDING_PRICING:1400_65_2 with thread：XNIO-1 task-4

2024-01-12T12:00:07.542088285Z 2024-01-12 12:00:07.541 INFO 7 --- [ XNIO-1 task-2] .s.p.a.t.c.h.i.test : locked by key:App:Procurement:PENDING_PRICING:1400_65_2 with thread：XNIO-1 task-2

[mrniko]

Please share the code to reproduce the issue.

[mrniko]

Make sure that the lock wasn't unlocked by the time when the second thread acquired it.

[OuDale]

Make sure that the lock wasn't unlocked by the time when the second thread acquired it.

Thanks reply,

1. the log shows that the two threads acquired the lock in a very short period of time. I don't think it is the case of releasing and acquiring the lock again.
2. I didn't assigned a leaseTime and unlocked in finally body.

private void generate() {
        RLock lock = redisson.getLock(key);
        try {
            String threadName = Thread.currentThread().getName();
            boolean locked = lock.tryLock();
            if (locked && shouldGenerateTask() {
                log.info("locked by key:{} with thread：{}", key, threadName);
                saveTask();
            }
        } catch (Exception e) {
            Thread.currentThread().interrupt();
        } finally {
            if (lock.isHeldByCurrentThread()) {
                lock.unlock();
            }
        }
    }

2024-01-12T12:00:07.514288425Z 2024-01-12 12:00:07.514 INFO 7 --- [ XNIO-1 task-4] .s.p.a.t.c.h.i.test : locked by key:App:Procurement:PENDING_PRICING:1400_65_2 with thread：XNIO-1 task-4

2024-01-12T12:00:07.542088285Z 2024-01-12 12:00:07.541 INFO 7 --- [ XNIO-1 task-2] .s.p.a.t.c.h.i.test : locked by key:App:Procurement:PENDING_PRICING:1400_65_2 with thread：XNIO-1 task-2

[OuDale]

This is occurring in a concurrent scenario where the real situation involves listening to a database change data capture (CDC). Then, two threads simultaneously acquire the lock and save two separate task data.

[mrniko]

Can you add log.info("unlocked1 by key:{} with thread：{}", key, threadName); after if (lock.isHeldByCurrentThread()) {

add log.info("unlocked2 by key:{} with thread：{}", key, threadName); after lock.unlock();

[OuDale]

thanks for your help