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From Jonathan Ellis <>
Subject Re: batch mutates & throughput
Date Mon, 08 Aug 2011 13:14:15 GMT
Hmm, can you create a ticket with a simple way to reproduce that?  We
should be giving back an InvalidRequestException for
multiple-mutations-on-same-key instead of erroring out later and
causing timeouts.

On Mon, Aug 8, 2011 at 12:34 AM, Philippe <> wrote:
> Hi Boris,
> Thanks for the suggestion, I didn't know there was one.
> I believe have finally figured it out and it turns out my last two questions
> are related.
> First, my batch loading was ignoring a bunch of rows when reading the first
> file (so it took hundreds of potential mutations for the problem to show up)
> and secondly, the ReplicateOnWriteStage error was generated by the batch
> mutations themselves and explained the TimedOutException : I was doing
> multiple mutations on the same key in one batch
> 2011/8/8 Boris Yen <>
>> Maybe you could try to adjust the setting "cassandraThriftSocketTimeout"
>> of hector.
>> On Mon, Aug 8, 2011 at 6:54 AM, Philippe <> wrote:
>>> Quick followup.
>>> I have pushed the RPC timeout to 30s. Using Hector, I'm doing 1 thread
>>> doing batches of 10 mutates at a time so that's even slower than when I was
>>> doing 16 threads in parallel doing non-batched mutations.
>>> After a couple hundred execute() calls, I get a timeout for every node; I
>>> have a 15 second grace period between retries. tpstats indicate no pendings
>>> on any of the nodes. I never recover from that
>>> I then set the batch size to one and it seems to work a lot better. The
>>> only difference I note is that the Mutator.execute() method returns a result
>>> than sometimes has a null host and 0 microsecond time in the batch sizes of
>>> ten but never in batch sizes of 1.
>>> I'm stumped ! Any ideas ?
>>> Thanks

Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of DataStax, the source for professional Cassandra support

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