Error executing DELETE_UNLOCK_SCRIPT on RedisPubSubLock

[nhmarujo]

In what version(s) of Spring Integration are you seeing this issue?

Between 6.4.9 and 6.5.6

Describe the bug

While releasing a lock, it tried to execute UNLINK_UNLOCK_REDIS_SCRIPT, but it timed out. For that reason, it fallback to execute DELETE_UNLOCK_REDIS_SCRIPT, but looking at that script it seems that a bug was introduced on the PUBLISH, so we are getting the following error:

Caused by: io.lettuce.core.RedisCommandExecutionException: ERR Lua redis lib command arguments must be strings or integers script: 4d7192f70618a620282e427698f9cde890151e58, on @user_script:3.

We believe this is happening because that call is being done like redis.call('PUBLISH', KEYS[2], KEYS[1]), while it should be like redis.call('PUBLISH', ARGV[2], KEYS[1]) (as it is done on UNLINK_UNLOCK_SCRIPT).

Since a failure to call unlink will mark unlinkAvailable = false, all subsequent unlocks will immediately try the DEL and fail on the publish.

We understand that this is fixed on the 7.x baseline (since that fallback got removed), but would be important to release a fix for this bug on the 6.x baseline, as many of us won't be able to bump to Spring Boot 4 in a near future.

To Reproduce

Hard to reproduce, needs to force unlink to fail. Perhaps reducing read timeout drastically?

Expected behavior

Publish would work as expected and application would continue to run normally using the delete.

[artembilan]

OK. So, the problem is here on 6.5.x branch:

		private static final String UNLINK_UNLOCK_SCRIPT = """
				local lockClientId = redis.call('GET', KEYS[1])
				if (lockClientId == ARGV[1] and redis.call('UNLINK', KEYS[1]) == 1) then
					redis.call('PUBLISH', ARGV[2], KEYS[1])
					return true
				end
				return false
				""";

		private static final String DELETE_UNLOCK_SCRIPT = """
				local lockClientId = redis.call('GET', KEYS[1])
				if (lockClientId == ARGV[1] and redis.call('DEL', KEYS[1]) == 1) then
					redis.call('PUBLISH', KEYS[2], KEYS[1])
					return true
				end
				return false
				""";

The UNLINK scripts uses ARGV[2], but DEL non-existing KEYS[2].

This was a result of this fix: #10570.
Where we just back-ported whatever we did in 7.0.x after removing DEL fallback.
So, the fix in 6.x was applied only for UNLINK.

Fixing this one quickly.

Sorry about that and thank you for sharing your pain!

[artembilan]

Fixed via 9aa0fc1

[nhmarujo]

Thank you @artembilan for the prompt answer 🙇 I was checking the calendar, but I don't think 6.5.7 release was planned. Can you please let us know if there is any due date for it? Thank you so much

[artembilan]

We’ve just released 6.5.6 couple days ago. The 6.5.7 will be in a month .

[nhmarujo]

Thank you @artembilan . I can see it on the calendar now. Have a nice weekend