Hmm it is highly unlikely that that is the culprit... There is lots of bandwidth available for me to use. I will definitely keep that in mind though. I was working on this today and have some tidbits of additional information and thoughts that you might be able to shed some light on:
- I mentioned I have 2 consumers, but each consumer is running with 8 threads for this topic (and each consumer has 8 cores available). - When I initially asked for help the brokers were configured with num.partitions=1, I've since tried higher numbers (3, 64) and haven't seen much of an improvement aside from forcing both consumer apps to handle messages (with the overall performance not changing much). - I ran into this article http://riccomini.name/posts/kafka/2012-10-05-kafka-consumer-memory-tuning/and tried a variety of options of queuedchunks.max and fetch.size with no significant results (simply meaning it did not achieve the goal of me constantly processing hundreds or thousands of messages per second, which is similar to the rate of input). I would not be surprised if I'm wrong but this made me start to think that the problem may lie outside of the consumers - Would the combination of a high number of partitions (64) and a high log.flush.interval (10k) prevent logs from flushing as often as they need to for my desired rate of consumption (even with log.default.flush.interval.ms=1000?) Despite the changes I mentioned the behaviour is still the consumers receiving larger spikes of messages mixed with periods of complete inactivity and overall a long delay between messages being written and messages being read (about 2 minutes). Anyway... as always I greatly appreciate any help. On Sun, Apr 21, 2013 at 8:50 PM, Jun Rao <jun...@gmail.com> wrote: > Is your network shared? Is so, another possibility is that some other apps > are consuming the bandwidth. > > Thanks, > > Jun > > > On Sun, Apr 21, 2013 at 12:23 PM, Andrew Neilson <arsneil...@gmail.com > >wrote: > > > Thanks very much for the reply Neha! So I swapped out the consumer that > > processes the messages with one that just prints them. It does indeed > > achieve a much better rate at peaks but can still nearly zero out (if not > > completely zero out). I plotted the messages printed in graphite to show > > the behaviour I'm seeing (this is messages printed per second): > > > > > > > https://www.dropbox.com/s/7u7uyrefw6inetu/Screen%20Shot%202013-04-21%20at%2011.44.38%20AM.png > > > > The peaks are over ten thousand per second and the troughs can go below > 10 > > per second just prior to another peak. I know that there are plenty of > > messages available because the ones currently being processed are still > > from Friday afternoon, so this may or may not have something to do with > > this pattern. > > > > Is there anything I can do to avoid the periods of lower performance? > > Ideally I would be processing messages as soon as they are written. > > > > > > On Sun, Apr 21, 2013 at 8:49 AM, Neha Narkhede <neha.narkh...@gmail.com > > >wrote: > > > > > Some of the reasons a consumer is slow are - > > > 1. Small fetch size > > > 2. Expensive message processing > > > > > > Are you processing the received messages in the consumer ? Have you > > > tried running console consumer for this topic and see how it performs > > > ? > > > > > > Thanks, > > > Neha > > > > > > On Sun, Apr 21, 2013 at 1:59 AM, Andrew Neilson <arsneil...@gmail.com> > > > wrote: > > > > I am currently running a deployment with 3 brokers, 3 ZK, 3 > producers, > > 2 > > > > consumers, and 15 topics. I should first point out that this is my > > first > > > > project using Kafka ;). The issue I'm seeing is that the consumers > are > > > only > > > > processing about 15 messages per second from what should be the > largest > > > > topic it is consuming (we're sending 200-400 ~300 byte messages per > > > second > > > > to this topic). I should note that I'm using a high level ZK consumer > > and > > > > ZK 3.4.3. > > > > > > > > I have a strong feeling I have not configured things properly so I > > could > > > > definitely use some guidance. Here is my broker configuration: > > > > > > > > brokerid=1 > > > > port=9092 > > > > socket.send.buffer=1048576 > > > > socket.receive.buffer=1048576 > > > > max.socket.request.bytes=104857600 > > > > log.dir=/home/kafka/data > > > > num.partitions=1 > > > > log.flush.interval=10000 > > > > log.default.flush.interval.ms=1000 > > > > log.default.flush.scheduler.interval.ms=1000 > > > > log.retention.hours=168 > > > > log.file.size=536870912 > > > > enable.zookeeper=true > > > > zk.connect=XXX > > > > zk.connectiontimeout.ms=1000000 > > > > > > > > Here is my producer config: > > > > > > > > zk.connect=XXX > > > > producer.type=async > > > > compression.codec=0 > > > > > > > > Here is my consumer config: > > > > > > > > zk.connect=XXX > > > > zk.connectiontimeout.ms=100000 > > > > groupid=XXX > > > > autooffset.reset=smallest > > > > socket.buffersize=1048576 > > > > fetch.size=10485760 > > > > queuedchunks.max=10000 > > > > > > > > Thanks for any assistance you can provide, > > > > > > > > Andrew > > > > > >
