apache / apache/kvrocks

XREAD got unexpected empty response

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#1,377 5 comments 1 reaction 0 assignees View on GitHub
bug
Dominant language
C++
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Forks
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Avg merge
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Merged PRs (30d)
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Description

### Search before asking

- [X] I had searched in the [issues](https://github.com/apache/incubator-kvrocks/issues) and found no similar issues.

### Version

OS:centos6.9
KVRocks:2.3.0
redis-cli:6.2.6/4.0.10

### Minimal reproduce step

I have a kvrocks cluster with 3 masters and 3 slaves.

Connect and blocking read the queue on master-A

```shell
redis-cli -c -h {Master A's IP} -p {Master A's Port} -a password
XREAD BLOCK 10000 STREAMS test-mq $
```

then publish a new message on master-B

```
redis-cli -c -h {Master B's IP} -p {Master B's Port} -a password
XADD test-mq * key1 value1
```

### What did you expect to see?

I would like to see normal consumption data, for example.
1) 1) "test-mq"
2) 1) 1) "1681209941456-0"
2) 1) "key1"
2) "value1"
(3.51s)

### What did you see instead?

I can see that the consume command in step 1 is unable to see the data and only sees an empty message.
(nil)
(10.00s)

### Anything Else?

_No response_

### Are you willing to submit a PR?

- [ ] I'm willing to submit a PR!

Contributor guide

No contributing guide indexed for this repository

Research direction

Reproduce the behavior with the provided redis-cli XREAD BLOCK and XADD commands against separate cluster masters, using the stated Kvrocks and Redis CLI versions. Trace the XREAD blocking behavior across the three-master cluster; done means a message added on master-B is returned to the blocked reader on master-A instead of nil after the timeout.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp, redis
Domain
databases, distributed-systems
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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