Thanks for the reply. You're definitely on to something with the ever-increasing number of sinks. :)
I scaled it back to 16 AvroSinks, and used a MemoryChannel.transactionCapacity of 1000, and AvroSink.batch-size of 1000. My ExecSource.batchSize is 100 (I chose this smaller number because there are so many of them (124), I didn't want 10s of thousands of events getting dropped on the MemoryChannel at once, rather just 1000s). With those settings, things are keeping the MemoryChannel drained. Finally getting somewhere! :) Much appreciate the prompt response. If anything else comes to mind, please do let me know. Thanks again. Chris On Tue, Mar 12, 2013 at 4:12 PM, Roshan Naik <[email protected]> wrote: > i meant 640,000 not 64,000 > > On Tue, Mar 12, 2013 at 2:10 PM, Roshan Naik <[email protected]> > wrote: > > beyond a certain # of sinks it wont help adding more. my suspicion is > > you may have gone way overboard. > > > > if your sink-side batch size is that large and you have 64 sinks in > > the round-robin.. it will take a lot of events (64,000) to be pumped > > in by the source order before the first event can start trickling out > > of any sink. Also memory consumption will be quite high.. each sink > > will open a transaction and hold on to 10000 events. This the cause > > for the Memory channel filling up. Until the sink side transaction is > > committed (i.e 10k events are pulled), the memory reservation on the > > channel is not relinquished. So your memory channel size will have to > > really high to support so manch sinks each with such a big batch size. > > > > My gut feel is that your source-side batch size is not much of an > > issue and can be smaller. Increasing the number of sinks will only > > help if the sink is indeed the bott > > > > On Tue, Mar 12, 2013 at 1:43 PM, Chris Neal <[email protected]> wrote: > >> Hi all. > >> > >> I've been working on this for quite some time, and need some advice > from the > >> experts. I have a two tiered Flume architecture: > >> > >> App Tier (all on one server): > >> 124 ExecSources -> MemoryChannel -> AvroSinks > >> > >> HDFS Tier (on two servers): > >> AvroSource -> FileChannel -> HDFSSinks > >> > >> When I run the agents, the HDFS tier is keeping up fine with the App > Tier. > >> queue sizes stay between 0-10000 (I have a batch size of 10000). All is > >> good. > >> > >> On the App Tier, when I view the JMX data through jconsole, I watch the > size > >> of the MemoryChannel grow steadily until it reaches the max, then it > starts > >> throwing exceptions about not being able to put the batch on the > channel as > >> expected. > >> > >> There seems to be two basic ways to increase the throughput of the App > Tier: > >> 1. Increase the MemoryChannel's transactionCapacity and the > corresponding > >> AvroSink's batch-size. Both are set to 10000 for me. > >> 2. Increase the number of AvroSinks to drain the MemoryChannel. I'm > up to > >> 64 Sinks now which round-robin between the two Flume Agents on the HDFS > >> tier. > >> > >> Both of those values seem quite high to me (batch size and number of > sinks). > >> > >> Am I missing something as far as tuning? > >> Which would allow for greater increase to throughput, more Sinks or > larger > >> batch size? > >> > >> I'm stumped here. I still think I can get this to work. :) > >> > >> Any suggestions are most welcome. > >> Thanks for your time. > >> Chris > >> >
