Zookeeper fsyncs the write requests to disk before acknowledging the writes as successful. Isn't that preventing what you described from happening?
No, we don't use RAID, I don't know about the non-volatile cache, I would have to check on that. > From: [email protected] > To: [email protected] > Subject: Re: Running zookeeper with journaling disabled on an ext4 > Date: Wed, 21 Oct 2015 17:59:33 +0000 > > If 3 of the 5 servers were to shutdown and the files on those servers were to > become corrupted, you would assuredly have data loss. > > Do you have your disks behind a raid controller with non-volatile cache (aka > write back cache)? > > Brian > > > > On Oct 21, 2015, at 9:49 AM, Adrian Hamza <[email protected]> wrote: > > > > Hi, > > What's your opinion on running Zookeeper with file system journaling > > disabled on an EXT4 file system? > > We need every ounce of performance out of it, and I believe given the > > Zookeeper implementation (operations are logged, majority quorum is > > required for succeeding, checkpoints are swapped only after being complete) > > I feel that EXT4 journaling is redundant. Disabling EXT4 journaling could > > improve performance. We have 5 servers in a Zookeeper ensemble. Am I > > missing something or this should be fine? > > Thank you, > > Adrian > > >
