We can reproduce this issue, have a theory as to the cause, and are working on a fix. Here is the ticket to track it: https://issues.apache.org/jira/browse/KAFKA-1952
I would recommend people hold off on 0.8.2 upgrades until we have a handle on this. -Jay On Fri, Feb 13, 2015 at 1:47 PM, Solon Gordon <so...@knewton.com> wrote: > The partitions nearly all have replication factor 2 (a few stray ones have > 1), and our producers use request.required.acks=-1. However, I should note > there were hardly any messages being produced when I did the upgrade and > observed the high CPU load. > > I should have time to do some profiling on Monday and will get back to you > with the results. > > On Fri, Feb 13, 2015 at 1:00 PM, Jun Rao <j...@confluent.io> wrote: > > > Solon, > > > > What's the replication factor you used for those partitions? What's the > > producer ack that you used? Also, could you do a bit of profiling on the > > broker to see which methods used the most CPU? > > > > Thanks, > > > > Jun > > > > On Thu, Feb 12, 2015 at 3:19 PM, Solon Gordon <so...@knewton.com> wrote: > > > > > I saw a very similar jump in CPU usage when I tried upgrading from > > 0.8.1.1 > > > to 0.8.2.0 today in a test environment. The Kafka cluster there is two > > > m1.larges handling 2,000 partitions across 32 topics. CPU usage rose > from > > > 40% into the 150%–190% range, and load average from under 1 to over 4. > > > Downgrading to 0.8.1.1 brought the CPU and load back to the previous > > > values. > > > > > > If there's more info that would be helpful, please let me know. > > > > > > On Thu, Feb 12, 2015 at 4:17 PM, Mathias Söderberg < > > > mathias.soederb...@gmail.com> wrote: > > > > > > > Jun, > > > > > > > > Pardon the radio silence. I booted up a new broker, created a topic > > with > > > > three (3) partitions and replication factor one (1) and used the > > > > *kafka-producer-perf-test.sh > > > > *script to generate load (using messages of roughly the same size as > > > ours). > > > > There was a slight increase in CPU usage (~5-10%) on 0.8.2.0-rc2 > > compared > > > > to 0.8.1.1, but that was about it. > > > > > > > > I upgraded our staging cluster to 0.8.2.0 earlier this week or so, > and > > > had > > > > to add an additional broker due to increased load after the upgrade > > (note > > > > that the incoming load on the cluster has been pretty much > consistent). > > > > Since the upgrade we've been seeing an 2-3x increase in latency as > > well. > > > > I'm considering downgrading to 0.8.1.1 again to see if it resolves > our > > > > issues. > > > > > > > > Best regards, > > > > Mathias > > > > > > > > On Tue Feb 03 2015 at 6:44:36 PM Jun Rao <j...@confluent.io> wrote: > > > > > > > > > Mathias, > > > > > > > > > > The new hprof doesn't reveal anything new to me. We did fix the > logic > > > in > > > > > using Purgatory in 0.8.2, which could potentially drive up the CPU > > > usage > > > > a > > > > > bit. To verify that, could you do your test on a single broker > (with > > > > > replication factor 1) btw 0.8.1 and 0.8.2 and see if there is any > > > > > significant difference in cpu usage? > > > > > > > > > > Thanks, > > > > > > > > > > Jun > > > > > > > > > > On Tue, Feb 3, 2015 at 5:09 AM, Mathias Söderberg < > > > > > mathias.soederb...@gmail.com> wrote: > > > > > > > > > > > Jun, > > > > > > > > > > > > I re-ran the hprof test, for about 30 minutes again, for > > 0.8.2.0-rc2 > > > > with > > > > > > the same version of snappy that 0.8.1.1 used. Attached the logs. > > > > > > Unfortunately there wasn't any improvement as the node running > > > > > 0.8.2.0-rc2 > > > > > > still had a higher load and CPU usage. > > > > > > > > > > > > Best regards, > > > > > > Mathias > > > > > > > > > > > > On Tue Feb 03 2015 at 4:40:31 AM Jaikiran Pai < > > > > jai.forums2...@gmail.com> > > > > > > wrote: > > > > > > > > > > > >> On Monday 02 February 2015 11:03 PM, Jun Rao wrote: > > > > > >> > Jaikiran, > > > > > >> > > > > > > >> > The fix you provided in probably unnecessary. The channel that > > we > > > > use > > > > > in > > > > > >> > SimpleConsumer (BlockingChannel) is configured to be blocking. > > So > > > > even > > > > > >> > though the read from the socket is in a loop, each read blocks > > if > > > > > there > > > > > >> is > > > > > >> > no bytes received from the broker. So, that shouldn't cause > > extra > > > > CPU > > > > > >> > consumption. > > > > > >> Hi Jun, > > > > > >> > > > > > >> Of course, you are right! I forgot that while reading the thread > > > dump > > > > in > > > > > >> hprof output, one has to be aware that the thread state isn't > > shown > > > > and > > > > > >> the thread need not necessarily be doing any CPU activity. > > > > > >> > > > > > >> -Jaikiran > > > > > >> > > > > > >> > > > > > >> > > > > > > >> > Thanks, > > > > > >> > > > > > > >> > Jun > > > > > >> > > > > > > >> > On Mon, Jan 26, 2015 at 10:05 AM, Mathias Söderberg < > > > > > >> > mathias.soederb...@gmail.com> wrote: > > > > > >> > > > > > > >> >> Hi Neha, > > > > > >> >> > > > > > >> >> I sent an e-mail earlier today, but noticed now that it > didn't > > > > > >> actually go > > > > > >> >> through. > > > > > >> >> > > > > > >> >> Anyhow, I've attached two files, one with output from a 10 > > minute > > > > run > > > > > >> and > > > > > >> >> one with output from a 30 minute run. Realized that maybe I > > > > should've > > > > > >> done > > > > > >> >> one or two runs with 0.8.1.1 as well, but nevertheless. > > > > > >> >> > > > > > >> >> I upgraded our staging cluster to 0.8.2.0-rc2, and I'm seeing > > the > > > > > same > > > > > >> CPU > > > > > >> >> usage as with the beta version (basically pegging all cores). > > If > > > I > > > > > >> manage > > > > > >> >> to find the time I'll do another run with hprof on the rc2 > > > version > > > > > >> later > > > > > >> >> today. > > > > > >> >> > > > > > >> >> Best regards, > > > > > >> >> Mathias > > > > > >> >> > > > > > >> >> On Tue Dec 09 2014 at 10:08:21 PM Neha Narkhede < > > > n...@confluent.io > > > > > > > > > > >> wrote: > > > > > >> >> > > > > > >> >>> The following should be sufficient > > > > > >> >>> > > > > > >> >>> java > > > > > >> >>> -agentlib:hprof=cpu=samples,depth=100,interval=20,lineno= > > > > > >> >>> y,thread=y,file=kafka.hprof > > > > > >> >>> <classname> > > > > > >> >>> > > > > > >> >>> You would need to start the Kafka server with the settings > > above > > > > for > > > > > >> >>> sometime until you observe the problem. > > > > > >> >>> > > > > > >> >>> On Tue, Dec 9, 2014 at 3:47 AM, Mathias Söderberg < > > > > > >> >>> mathias.soederb...@gmail.com> wrote: > > > > > >> >>> > > > > > >> >>>> Hi Neha, > > > > > >> >>>> > > > > > >> >>>> Yeah sure. I'm not familiar with hprof, so any particular > > > > options I > > > > > >> >>> should > > > > > >> >>>> include or just run with defaults? > > > > > >> >>>> > > > > > >> >>>> Best regards, > > > > > >> >>>> Mathias > > > > > >> >>>> > > > > > >> >>>> On Mon Dec 08 2014 at 7:41:32 PM Neha Narkhede < > > > > n...@confluent.io> > > > > > >> >>> wrote: > > > > > >> >>>>> Thanks for reporting the issue. Would you mind running > hprof > > > and > > > > > >> >>> sending > > > > > >> >>>>> the output? > > > > > >> >>>>> > > > > > >> >>>>> On Mon, Dec 8, 2014 at 1:25 AM, Mathias Söderberg < > > > > > >> >>>>> mathias.soederb...@gmail.com> wrote: > > > > > >> >>>>> > > > > > >> >>>>>> Good day, > > > > > >> >>>>>> > > > > > >> >>>>>> I upgraded a Kafka cluster from v0.8.1.1 to v0.8.2-beta > and > > > > > noticed > > > > > >> >>>> that > > > > > >> >>>>>> the CPU usage on the broker machines went up by roughly > > 40%, > > > > from > > > > > >> >>> ~60% > > > > > >> >>>> to > > > > > >> >>>>>> ~100% and am wondering if anyone else has experienced > > > something > > > > > >> >>>> similar? > > > > > >> >>>>>> The load average also went up by 2x-3x. > > > > > >> >>>>>> > > > > > >> >>>>>> We're running on EC2 and the cluster currently consists > of > > > four > > > > > >> >>>>> m1.xlarge, > > > > > >> >>>>>> with roughly 1100 topics / 4000 partitions. Using Java 7 > > > > > (1.7.0_65 > > > > > >> >>> to > > > > > >> >>>> be > > > > > >> >>>>>> exact) and Scala 2.9.2. Configurations can be found over > > > here: > > > > > >> >>>>>> https://gist.github.com/mthssdrbrg/7df34a795e07eef10262. > > > > > >> >>>>>> > > > > > >> >>>>>> I'm assuming that this is not expected behaviour for > > > > 0.8.2-beta? > > > > > >> >>>>>> > > > > > >> >>>>>> Best regards, > > > > > >> >>>>>> Mathias > > > > > >> >>>>>> > > > > > >> >>>>> > > > > > >> >>>>> > > > > > >> >>>>> -- > > > > > >> >>>>> Thanks, > > > > > >> >>>>> Neha > > > > > >> >>>>> > > > > > >> >>> > > > > > >> >>> > > > > > >> >>> -- > > > > > >> >>> Thanks, > > > > > >> >>> Neha > > > > > >> >>> > > > > > >> > > > > > >> > > > > > > > > > > > > > > >
