Jun Rao created KAFKA-1430:
------------------------------
Summary: Purgatory redesign
Key: KAFKA-1430
URL: https://issues.apache.org/jira/browse/KAFKA-1430
Project: Kafka
Issue Type: Improvement
Components: core
Affects Versions: 0.8.2
Reporter: Jun Rao
We have seen 2 main issues with the Purgatory.
1. There is no atomic checkAndWatch functionality. So, a client typically first
checks whether a request is satisfied or not and then register the watcher.
However, by the time the watcher is registered, the registered item could
already be satisfied. This item won't be satisfied until the next update
happens or the delayed time expires, which means the watched item could be
delayed.
2. FetchRequestPurgatory doesn't quite work. This is because the current design
tries to incrementally maintain the accumulated bytes ready for fetch. However,
this is difficult since the right time to check whether a fetch (for regular
consumer) request is satisfied is when the high watermark moves. At that point,
it's hard to figure out how many bytes we should incrementally add to each
pending fetch request.
The problem has been reported in KAFAK-1150 and KAFKA-703.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
