event service received resolved-ts lag should not spike if the downstream sink is the bottleneck
Open
Nobody has claimed this yet.
severity/moderate
type/enhancement
- Dominant language
- Go
- Stars
- 56
- Forks
- 63
- Avg merge
- 2d 20h
- Merged PRs (30d)
- 34
Description
run kafka sink changefeed, and inject network latency chaos, the latency is around 10 ~ 20 ms
- The checkpoint lag increase is expected, since write to the downstream is too slow now.
- resolved-ts lag also increased, this is not expected. resolved-ts should only relevant to receive data from the upstream.
- event store resolved-ts lag is stable, this is expected.
- event service received resolved-ts lag is almost identical to the changefeed resolved-ts. It also spikes, it's not expected.
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
Reproduce the Kafka sink changefeed with injected network latency and compare checkpoint lag, changefeed resolved-ts lag, event store resolved-ts lag, and event service received resolved-ts lag. Trace how resolved-ts moves through the event service and confirm that downstream sink latency no longer causes the received resolved-ts metric to spike.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- go, kafka
- Domain
- observability, stream-processing
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 35/100