Hi Ilya,
You will always blow up if you use consistancy level zero to write
gigs of data. The safe minimum for writes is ONE. Zero is meant for
small non batched writes.
Also look into batch_mutation call to write lots of data at once, in a
series of chunks. this helps save on network back and forth.
-Jake
On Apr 6, 2010, at 3:18 AM, Ilya Maykov <ivmay...@gmail.com> wrote:
Right, I meant 4GB heap vs. the standard 1GB. And all other options in
cassandra.in.sh at their defaults.
Sorry I am a bit new to JVM tuning, and very new to Cassandra :)
-- Ilya
On Tue, Apr 6, 2010 at 12:16 AM, Benjamin Black <b...@b3k.us> wrote:
I am specifically suggesting you NOT use a heap that large with your
8GB machines. Please test with 4GB first.
On Tue, Apr 6, 2010 at 12:13 AM, Ilya Maykov <ivmay...@gmail.com>
wrote:
That does sound similar. It's possible that the difference I'm
seeing
between ConsistencyLevel.ZERO and ConsistencyLevel.ALL is simply due
to the fact that using ALL slows down the writers enough that the GC
can keep up. I could do a test with multiple clients writing at
ALL in
parallel tomorrow. If there are still no problems writing at ALL
even
with extra load from additional clients, that might point to
problems
in how async writes are handled vs. sync writes.
I will also do some profiling of the server processes with both ZERO
and ALL writer behaviors and report back.
RE: JVM_OPTS, I will try running with the "more sane" options (but a
larger heap) as well.
-- Ilya
On Mon, Apr 5, 2010 at 11:59 PM, Rob Coli <rc...@digg.com> wrote:
On 4/5/10 11:48 PM, Ilya Maykov wrote:
No, the disks on all nodes have about 750GB free space. Also as
mentioned in my follow-up email, writing with ConsistencyLevel.ALL
makes the slowdowns / crashes go away.
I am not sure if the above is consistent with the cause of #896,
but the
other symptoms ("I inserted a bunch of data really fast via
Thrift and GC
melted my machine!") sound like it..
https://issues.apache.org/jira/browse/CASSANDRA-896
=Rob
