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Flume, mail # user - Best way to increase throughput of Exec->Memory->Avro agent.


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Re: Best way to increase throughput of Exec->Memory->Avro agent.
Chris Neal 2013-03-12, 21:40
Beautiful.  Will try 4 channels in one Agent first.
Thanks!
On Tue, Mar 12, 2013 at 4:35 PM, Roshan Naik <[EMAIL PROTECTED]> wrote:

> Even 16 on a single channel might be on the higher side IMHO.
>
> Try instead splitting into four channels with 4 sinks each... or even
> four agents with one channel and 4 sinks each ..... it will reduce
> contention. be careful to ensure your capacity of each channel is not
> too high since you now have many channels.
> -roshan
>
> On Tue, Mar 12, 2013 at 2:24 PM, Chris Neal <[EMAIL PROTECTED]> wrote:
> > 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).