incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jonathan Ellis <jbel...@gmail.com>
Subject Re: repeated timeouts on quorum reads
Date Tue, 20 Oct 2009 01:01:24 GMT
are there many rows like this?

did you check the logs on the other nodes for exceptions?

On Mon, Oct 19, 2009 at 7:40 PM, Edmond Lau <edmond@ooyala.com> wrote:
> Usually I'm trying to read 500 columns (~250KB) out of the 30K columns
> (~15MB) of the supercolumn.  But the same issues happen when I drop
> down to 100 (~50KB) columns.  The columns I request from get_slice()
> are named, i.e. I'm not reading 500 consecutive columns.
>
> Edmond
>
> On Mon, Oct 19, 2009 at 5:36 PM, Jonathan Ellis <jbellis@gmail.com> wrote:
>> How much of the row that fails are you trying to read at once?
>>
>> On Mon, Oct 19, 2009 at 7:30 PM, Edmond Lau <edmond@ooyala.com> wrote:
>>> Whenever I try to do a quorum read on a row with a particularly large
>>> supercolumn with get_slice under high load, cassandra throws timeouts.
>>>  The reads for that row repeatedly fail until load decreases, but
>>> smaller reads still succeed during that time.  bin/nodeprobe info
>>> shows that the read latency for the column family spikes to up 6-8
>>> seconds.  I've run into this issue since I started to play with
>>> cassandra, but thought that it might go away with beefier nodes.  I've
>>> since gotten more powerful machines, but the timeouts still happen.
>>>
>>> Some details:
>>> - cassandra 0.4.1
>>> - 5 nodes, each with 12-core 800MHz with 8GB RAM, 5GB heap size
>>> - replication factor of 3
>>> - RandomPartitioner
>>> - row that fails has a supercolumn with ~30K subcolumns, ~500 bytes
>>> per cell, ~15MB total
>>> - my failed quorum read lists 500 columns to read in the get_slice
>>> call, but the same happens even when I read 100.
>>>
>>> The nodes either timeout with 0 or 1 responses (2 of 3 required for a
>>> quorum read):
>>>
>>> ERROR [pool-1-thread-24] 2009-10-20 00:07:43,851 Cassandra.java (line
>>> 679) Internal error processing get_slice
>>> java.lang.RuntimeException: java.util.concurrent.TimeoutException:
>>> Operation timed out - received only 0 responses from  .
>>>        at org.apache.cassandra.service.CassandraServer.readColumnFamily(CassandraServer.java:108)
>>>        at org.apache.cassandra.service.CassandraServer.getSlice(CassandraServer.java:182)
>>>        at org.apache.cassandra.service.CassandraServer.multigetSliceInternal(CassandraServer.java:251)
>>>        at org.apache.cassandra.service.CassandraServer.get_slice(CassandraServer.java:220)
>>>        at org.apache.cassandra.service.Cassandra$Processor$get_slice.process(Cassandra.java:671)
>>>        at org.apache.cassandra.service.Cassandra$Processor.process(Cassandra.java:627)
>>>        at org.apache.thrift.server.TThreadPoolServer$WorkerProcess.run(TThreadPoolServer.java:253)
>>>        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
>>>        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
>>>        at java.lang.Thread.run(Thread.java:619)
>>> Caused by: java.util.concurrent.TimeoutException: Operation timed out
>>> - received only 0 responses from  .
>>>        at org.apache.cassandra.service.QuorumResponseHandler.get(QuorumResponseHandler.java:88)
>>>        at org.apache.cassandra.service.StorageProxy.strongRead(StorageProxy.java:395)
>>>        at org.apache.cassandra.service.StorageProxy.readProtocol(StorageProxy.java:317)
>>>        at org.apache.cassandra.service.CassandraServer.readColumnFamily(CassandraServer.java:100)
>>>        ... 9 more
>>>
>>> ERROR [pool-1-thread-32] 2009-10-19 23:47:21,045 Cassandra.java (line
>>> 679) Internal error processing get_slice
>>> java.lang.RuntimeException: java.util.concurrent.TimeoutException:
>>> Operation timed out - received only 1 responses from
>>> 172.16.129.75:7000 .
>>>        at org.apache.cassandra.service.CassandraServer.readColumnFamily(CassandraServer.java:108)
>>>        at org.apache.cassandra.service.CassandraServer.getSlice(CassandraServer.java:182)
>>>        at org.apache.cassandra.service.CassandraServer.multigetSliceInternal(CassandraServer.java:251)
>>>        at org.apache.cassandra.service.CassandraServer.get_slice(CassandraServer.java:220)
>>>        at org.apache.cassandra.service.Cassandra$Processor$get_slice.process(Cassandra.java:671)
>>>        at org.apache.cassandra.service.Cassandra$Processor.process(Cassandra.java:627)
>>>        at org.apache.thrift.server.TThreadPoolServer$WorkerProcess.run(TThreadPoolServer.java:253)
>>>        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
>>>        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
>>>        at java.lang.Thread.run(Thread.java:619)
>>> Caused by: java.util.concurrent.TimeoutException: Operation timed out
>>> - received only 1 responses from 172.16.129.75:7000 .
>>>        at org.apache.cassandra.service.QuorumResponseHandler.get(QuorumResponseHandler.java:88)
>>>        at org.apache.cassandra.service.StorageProxy.strongRead(StorageProxy.java:395)
>>>        at org.apache.cassandra.service.StorageProxy.readProtocol(StorageProxy.java:317)
>>>        at org.apache.cassandra.service.CassandraServer.readColumnFamily(CassandraServer.java:100)
>>>        ... 9 more
>>>
>>> Any ideas what the issue might be?
>>>
>>> Edmond
>>>
>>
>

Mime
View raw message