changefeed resolvedTs lag increase after pausing to write data upstream
Open
Nobody has claimed this yet.
severity/moderate
type/bug
- Dominant language
- Go
- Stars
- 56
- Forks
- 63
- Avg merge
- 2d 20h
- Merged PRs (30d)
- 34
Description
What did you do?
- start a changefeed with mysql
- write data upstream
- start 50 changefeed with blackhole
- pause to write data upstream
What did you expect to see?
No response
What did you see instead?
The changefeed resovledTs lag increase.
The sink writes zero bytes, which means all data should be replicated to the downstream.
Versions of the cluster
Upstream TiDB cluster version (execute SELECT tidb_version(); in a MySQL client):
(paste TiDB cluster version here)
Upstream TiKV version (execute tikv-server --version):
(paste TiKV version here)
TiCDC version (execute cdc version):
release-8.5
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
No source file, test, or entry point is named. Reproduce the release-8.5 scenario with MySQL, 50 blackhole changefeeds, and upstream writes while paused; inspect resolvedTs lag and sink byte metrics. Done means the resolvedTs lag does not increase when the sink writes zero bytes, with a regression test or clear diagnostic evidence.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- go
- Domain
- data-engineering, distributed-systems
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Quiet
- Clarity
- Needs clarification
- Newbie friendliness
- 35/100