zookeeper-notifications mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From GitBox <...@apache.org>
Subject [GitHub] [zookeeper] lvfangmin opened a new pull request #1047: [ZOOKEEPER-3500] Improving the ZAB UPTODATE semantic to only issue it to learner when there is limited lagging
Date Thu, 08 Aug 2019 18:15:09 GMT
lvfangmin opened a new pull request #1047: [ZOOKEEPER-3500] Improving the ZAB UPTODATE semantic
to only issue it to learner when there is limited lagging
URL: https://github.com/apache/zookeeper/pull/1047
 
 
   With large snapshot and high write RPS, when learner is having SNAP syncing with leader,
there will be lots of txns need to be replayed between NEWLEADER and UPTODATE packet.
    
   Depends how big the snapshot and traffic is, from our benchmark, it may take more than
30s to replay all those txns, which means when we process the UPTODATE packet, it's still
30s lagging behind, with 10K/s txn that's 300K txns lagging. 
    
   And we start to serve client traffic just after we received UPTODATE packet, which means
client will see lots of stale data.
    
   The idea here is trying to check and only send UPTODATE packet when there is limited txns
lagging behind from leader side. It doesn't change the ZAB protocol, but changed the time
when ZK is applying the txns between NEWLEADER and UPTODATE. 
    
   We haven't merged this change internally, we'd like to hear some feedback here, please
help review and let us know if there is any red flag of doing this.

----------------------------------------------------------------
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:
users@infra.apache.org


With regards,
Apache Git Services

Mime
View raw message