On Wed, Oct 3, 2012 at 9:12 PM, Jun Rao <[EMAIL PROTECTED]> wrote:
> Thanks for the info. Does each ZK write wait for log being flushed to disk?
Yes (it's necessary for the guarantees we provide), although the
servers do batching of writes to improve throughput. This doc gives
some insight: http://zookeeper.apache.org/doc/r3.4.4/zookeeperOver.html#Performance
> On Wed, Oct 3, 2012 at 6:13 PM, Patrick Hunt <[EMAIL PROTECTED]> wrote:
>> My experience with SSDs and ZK has been discouraging. SSDs have some
>> really terrible corner cases for latency. I've seen them take 40+
>> seconds (that's not a mistake - seconds) for fsync to complete. When
>> this happened (every few hours) all of the sessions would timeout.
>> See this article:
>> On Wed, Oct 3, 2012 at 9:59 AM, Jun Rao <[EMAIL PROTECTED]> wrote:
>> > Hi,
>> > Will storing the ZK commit log on SSD improve ZK write latency? Does a ZK
>> > write wait until data is flushed to disk?
>> > Thanks,
>> > Jun