Hi Ibrahim, In async tests, could you give the details like:
* number of clients * number of threads * data size storing in each znode Also, it would be good to monitor : 1) JVM stats(one way is through JMX) like heap, gc activities. This is to see if latency spike corresponds to gc activity or not. 2) Since you are doubting fsync, I think $ iostat would be helpful to see disk statistics. For example, $ iostat -d -x 2 10 and collects the disk latency. 3) CPU usage through top or sar unix commands. I didn't use sar , but I could see it gives more details like percent of CPU running idle with a process waiting for block I/O etc. -Rakesh On Thu, Oct 23, 2014 at 6:44 PM, Alexander Shraer <[email protected]> wrote: > Maybe due to queueing at the leader in asynchronous mode - if in your > experiment you have one client in sync mode the leader has just one op in > the queue at a time > On Oct 23, 2014 1:57 PM, "Ibrahim" <[email protected]> wrote: > > > Hi folks, > > > > I am testing ZooKeeper latency in Asynchronous mode. I am sending update > > (write) requests to Zookeeper cluster that consists of 5 physical > > Zookeeper. > > > > So, when I run the stat command I get high latency like: > > Latency min/avg/max: 7/339/392 > > Latency min/avg/max: 1/371/627 > > Latency min/avg/max: 1/371/627 > > Latency min/avg/max: 1/364/674 > > I guess such high latency correspond to fsync (batch requests). But I > wish > > if someone could help me and explain this behaviour. > > > > However, testing Zookeeper using Synchronous mode, it gives me reasonable > > result like: > > Latency min/avg/max: 6/24/55 > > Latency min/avg/max: 7/22/61 > > Latency min/avg/max: 7/30/65 > > > > Note that the latency measures in milliseconds. > > > > I look forward to hearing from you. > > > > Ibrahim > > > > > > > > > > > > > > > > -- > > View this message in context: > > > http://zookeeper-user.578899.n2.nabble.com/Latency-in-asynchronous-mode-tp7580446.html > > Sent from the zookeeper-user mailing list archive at Nabble.com. > > >
