On Tue, Nov 27, 2012 at 4:40 AM, Brian Tarbox <[email protected]> wrote: > Does this warning mean a: the log is too big, b: zk is competing with another > process for disk access, c: other? >
That's timing how long the fsync takes on the txnlog, typically it runs log because the disk is busy, or the OS has a large number of dirty pages on the volume (ext3 esp), etc... > How should one respond to the warning? The admin and troubleshooting guides both provide some insight, but in particular the txnlog should be on a dedicated spindle (non-vm obv) if you care about performance (latency). Any fsync timing that's large than/near your session timeout is going to be trouble. Patrick > On Nov 27, 2012, at 2:47 AM, Patrick Hunt <[email protected]> wrote: > >> On Mon, Nov 26, 2012 at 11:43 PM, Narayanan A R >> <[email protected]> wrote: >>> Have you seen this before? >>> >>> 2012-11-25 16:01:08,074 [myid:1] - WARN [SyncThread:1:FileTxnLog@321] - >>> fsync-ing the write ahead log in SyncThread:1 took 1470ms which will >>> adversely effect operation latency. See the ZooKeeper troubleshooting guide >>> >>> I am running ZK cluster of size 3 in a VM. >> >> Yes, I added it recently to highlight situations where environment >> could adversely effect ZK latency. >> >> Patrick
