Hi, ZK uses a quorum protocol (similar but not the same as paxos) for
writes, as a result it's sensitive to inter-server latency. (however
reads are always local and therefore not effected) Running a cluster
fully w/in a colo you can achieve 15k writes/second, with a cluster
distributed across
Agree with David, it's not there and thinking about how the data is laid
out on disk, it can't be done without changing core code or harming
something else.
if this is a performance concern
It's not, it was to supply an administrative function on SuperColumns,
but it would be good to not
Hi Benjamin.
Ok.
Thank's for your anwser.
-Message d'origine-
De : Benjamin Black [mailto:b...@b3k.us]
Envoyé : lundi 17 mai 2010 00:08
À : user@cassandra.apache.org
Objet : Re: Nodes Levels of Hierarchy in Cassandra.
Not in Cassandra.
Your description of the levels is not quite
At any given moment at least half of those threads are in the following
state; what does it represent?
Name: ROW-READ-STAGE:6
State: WAITING on
java.util.concurrent.locks.abstractqueuedsynchronizer$conditionobj...@fea6030
Total blocked: 44 Total waited: 479
Stack trace:
There is only one partitioner, and that alone is what determines key
- token mapping. CF has nothing to do with it.
On Mon, May 17, 2010 at 4:55 AM, Miriam Allalouf
miriam.allal...@gmail.com wrote:
Hi,
I have a basic question regarding key ranges and partitions.
Assuming we have two CF column
On Fri, 2010-05-14 at 14:52 -0600, David Wellman wrote:
Does anyone have a good link or example code that we can use to spike on Avro
with Cassandra?
If you're using Python, the best place to look is the functional tests
(see test/system), otherwise, Patrick's quick start
I had this happen when I changed the seed node in a running cluster, and
then started and stopped various nodes. I fixed it by restarting
the seed node(s) (and waiting for it to be fully up), then restarting
all the other nodes.
-Anthony
On Fri, May 14, 2010 at 05:11:40PM -0700, David Koblas
I spent the weekend working with avro and some java junit tests. I
still have a lot of learning to do, but if others would like to use,
add to or improve upon the tests then I would appricate the feedback
and help.
David Wellman
On May 17, 2010, at 10:16 AM, Eric Evans
Hello,
We are getting our feet wet with Cassandra and have a test environment
set up to do some heavy data insertion. [Heavy is relative: we are
talking about 1M inserts in a 3 hours test.
Twice while running these tests, when we've tried to use 'nodetool'
about an hour or so into the test,
Moving to the user@ list.
http://wiki.apache.org/cassandra/HadoopSupport should be useful.
On Mon, May 17, 2010 at 2:41 PM, Yan Virin jan.vi...@gmail.com wrote:
Hi,
Can someone explain how this works? As long as I know, there is no execution
engine in Cassandra alone, so I assume that Hadoop
do both nodes see each other in nodetool ring?
On Fri, May 14, 2010 at 4:47 PM, li wei liwei...@yahoo.com wrote:
Hi, Guys,
I have a lasted cassandra -0.6.0.-rc1.
Connect one node1 from java. Node 1 is OK, node 2 has this error:
(if Connect one node2 from java. Node 2 is OK, node 1 has same
Brandon Williams wrote:
On Mon, May 17, 2010 at 2:44 PM, Ronald Park ronald.p...@cbs.com
mailto:ronald.p...@cbs.com wrote:
Hello,
We are getting our feet wet with Cassandra and have a test
environment set up to do some heavy data insertion. [Heavy is
relative: we are talking
Jonathan,
Curious how many people have signed up?
I hope you will do another one soon!
On Tue, May 11, 2010 at 12:42 PM, Vick Khera vi...@khera.org wrote:
On Fri, May 7, 2010 at 6:56 AM, Matt Revelle mreve...@gmail.com wrote:
Reston, VA is a good spot in the DC metro area for tech events.
Hi!
Which JMX metrics do you use for Cassandra monitoring ? Which values can
be used for alerts ?
Can you provide us with the current JVM args? Also, what type of work load
you are giving the ring (op/s)?
On Mon, May 17, 2010 at 6:39 PM, Curt Bererton c...@zipzapplay.com wrote:
Hello Cassandra users+experts,
Hopefully someone will be able to point me in the correct direction. We
have
On Mon, May 17, 2010 at 6:02 PM, Curt Bererton c...@zipzapplay.com wrote:
So pretty much the defaults aside from the 7Gig max heap. CPU is totally
hammered right now, and it is receiving 0 ops/sec from me since I
disconnected it from our application right now until I can figure out what's
What are your storage-conf settings for Memtable thresholds? One thing that
could cause lots of CPU usage is dumping the memtables too frequently and
then having to do lots of compaction. With that much available heap space
you could definitely go larger than the default thresholds. Also, do
Also, I am using batch_mutate for all of my writes.
Lee Parker
On Mon, May 17, 2010 at 7:11 PM, Lee Parker l...@socialagency.com wrote:
What are your storage-conf settings for Memtable thresholds? One thing
that could cause lots of CPU usage is dumping the memtables too frequently
and then
On Mon, May 17, 2010 at 4:12 PM, Vick Khera vi...@khera.org wrote:
On Mon, May 17, 2010 at 3:46 PM, Jonathan Ellis jbel...@gmail.com wrote:
Moving to the user@ list.
http://wiki.apache.org/cassandra/HadoopSupport should be useful.
That document doesn't really answer the is data locality
Thanks for the help guys:
First answering the first question: both cores are pegged:
Cpu0 : 43.8%us, 34.0%sy, 0.0%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.0%si,
22.1%st
Cpu1 : 40.5%us, 36.2%sy, 0.0%ni, 0.4%id, 0.0%wa, 0.0%hi, 0.2%si,
22.6%st
Mem: 7872040k total, 3620180k used, 4251860k
Agreed, and I just saw that in storage conf that a higher value for the
MemtableFlushAfterMinutes is suggested otherwise you might get a flush
storm: of all your memtables flushing at once. I've changed that as well.
--
Curt, ZipZapPlay Inc., www.PlayCrafter.com,
After upgrading my cluster from 0.5.1 to the 0.6 branch (commit 1206bcf in
git). I am seeing lots of IO errors in the log output.
Two questions:
1. Is this a sign that I have corrupt data? Is there some way for me to
recover it or at the very least remove the bad data?
2. If this is an
There are many, but here's what I found useful so far:
Per CF you have:
- Recent read/write latency
- PendingTasks
- Read/Write count
Globally you have, for each of the stages
(e.g. org.apache.cassandra.concurrent:type=ROW-READ-STAGE):
- PendingTasks
- ActiveCount
... and as you go you'll find
I found out what was wrong. The schema file had gotten changed but not
deployed to the cluster recently. During the migration the new schema was
used. A column family got switched from a normal column family to a super
column family.
Stephen Hamer
On Mon, May 17, 2010 at 6:16 PM, Stephen Hamer
Hi all,
Recently we have a 5 nodes running cassandra, 4 X 1.5TB drives for each,
I installed os(Ubuntu 9.10 Server Edition) on one of them, and make entrie
disk as 1 partition for others, then I put 4 paths with DataFileDirectory,
my question is what's going to happen when one of the disk
After performing nodetool compact command the disk usage was doubled.
nodetool info reports that the load is 74G (same as before compaction) while
the size of the data folder on disk is 133GB (was about 74G before compaction).
I'm currently moving my existing mysql database to cassandra. One particular
problem I have is to migrate all those integer auto-increment ids to
cassandra's code generated keys (like UUID). One way I can do is to dump all
the existing records into Cassandra and start with UUID for new records,
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