jiajunwang commented on issue #331: CallbackHandler async re-subscribe watcher can potentially miss events URL: https://github.com/apache/helix/issues/331#issuecomment-513984628 The root cause of the issue is a race condition in Helix cache refresh logic. Basically, Helix relies on the ZK notification path to set up 2 things: 1. If the current assignment is still valid. 2. If the data cache needs to be refreshed. The race condition causes these 2 checks to have a different result. The assignment was not invalidated. But the cache was updated. As a result, the rebalancer refused to calculate a new mapping even knows the latest IdealState. The impact is limited in the CUSTOM rebalance mode only. Because the fist check is done for custom rebalancer only.
---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
