The problem is you have a few MB of actual data and a few hundred MB of tombstones (data marked deleted). So what happens is get_key_range spends a long, long time iterating through the tombstoned rows, looking for keys that actually still exist.
We're going to redesign this for CASSANDRA-344, but for the 0.4 series, you should restart with GCGraceSeconds much lower (e.g. 3600), delete your old data files, and reload your data fresh. (Instead of reloading, you can use "nodeprobe compact" on each node to force a major compaction but it will take much longer since you have so many tombstones). -Jonathan On Mon, Oct 19, 2009 at 10:45 PM, Ramzi Rabah <rra...@playdom.com> wrote: > Hi Jonathan: > > Here is the storage_conf.xml for one of the servers > http://email.slicezero.com/storage-conf.xml > > and here is the zipped data: > http://email.slicezero.com/datastoreDeletion.tgz > > Thanks > Ray > > > > > On Mon, Oct 19, 2009 at 8:30 PM, Jonathan Ellis <jbel...@gmail.com> wrote: >> Yes, please. You'll probably have to use something like >> http://www.getdropbox.com/ if you don't have a public web server to >> stash it temporarily. >> >> On Mon, Oct 19, 2009 at 10:28 PM, Ramzi Rabah <rra...@playdom.com> wrote: >>> Hi Jonathan the data is about 60 MB. Would you like me to send it to you? >>> >>> >>> On Mon, Oct 19, 2009 at 8:20 PM, Jonathan Ellis <jbel...@gmail.com> wrote: >>>> Is the data on 6, 9, or 10 small enough that you could tar.gz it up >>>> for me to use to reproduce over here? >>>> >>>> On Mon, Oct 19, 2009 at 10:17 PM, Ramzi Rabah <rra...@playdom.com> wrote: >>>>> So my cluster has 4 nodes node6, node8, node9 and node10. I turned >>>>> them all off. >>>>> 1- I started node6 by itself and still got the problem. >>>>> 2- I started node8 by itself and it ran fine (returned no keys) >>>>> 3- I started node9 by itself and still got the problem. >>>>> 4- I started node10 by itself and still got the problem. >>>>> >>>>> Ray >>>>> >>>>> >>>>> >>>>> On Mon, Oct 19, 2009 at 7:44 PM, Jonathan Ellis <jbel...@gmail.com> wrote: >>>>>> That's really strange... Can you reproduce on a single-node cluster? >>>>>> >>>>>> On Mon, Oct 19, 2009 at 9:34 PM, Ramzi Rabah <rra...@playdom.com> wrote: >>>>>>> The rows are very small. There are a handful of columns per row >>>>>>> (approximately about 4-5 columns per row). >>>>>>> Each column has a name which is a String (20-30 characters long), and >>>>>>> the value is an empty array of bytes (new byte[0]). >>>>>>> I just use the names of the columns, and don't need to store any >>>>>>> values in this Column Family. >>>>>>> >>>>>>> -- Ray >>>>>>> >>>>>>> On Mon, Oct 19, 2009 at 7:24 PM, Jonathan Ellis <jbel...@gmail.com> >>>>>>> wrote: >>>>>>>> Can you tell me anything about the nature of your rows? Many/few >>>>>>>> columns? Large/small column values? >>>>>>>> >>>>>>>> On Mon, Oct 19, 2009 at 9:17 PM, Ramzi Rabah <rra...@playdom.com> >>>>>>>> wrote: >>>>>>>>> Hi Jonathan >>>>>>>>> I actually spoke too early. Now even if I restart the servers it still >>>>>>>>> gives a timeout exception. >>>>>>>>> As far as the sstable files are, not sure which ones are the sstables, >>>>>>>>> but here is the list of files in the data directory that are prepended >>>>>>>>> with the column family name: >>>>>>>>> DatastoreDeletionSchedule-1-Data.db >>>>>>>>> DatastoreDeletionSchedule-1-Filter.db >>>>>>>>> DatastoreDeletionSchedule-1-Index.db >>>>>>>>> DatastoreDeletionSchedule-5-Data.db >>>>>>>>> DatastoreDeletionSchedule-5-Filter.db >>>>>>>>> DatastoreDeletionSchedule-5-Index.db >>>>>>>>> DatastoreDeletionSchedule-7-Data.db >>>>>>>>> DatastoreDeletionSchedule-7-Filter.db >>>>>>>>> DatastoreDeletionSchedule-7-Index.db >>>>>>>>> DatastoreDeletionSchedule-8-Data.db >>>>>>>>> DatastoreDeletionSchedule-8-Filter.db >>>>>>>>> DatastoreDeletionSchedule-8-Index.db >>>>>>>>> >>>>>>>>> I am not currently doing any system stat collection. >>>>>>>>> >>>>>>>>> On Mon, Oct 19, 2009 at 6:41 PM, Jonathan Ellis <jbel...@gmail.com> >>>>>>>>> wrote: >>>>>>>>>> How many sstable files are in the data directories for the >>>>>>>>>> columnfamily you are querying? >>>>>>>>>> >>>>>>>>>> How many are there after you restart and it is happy? >>>>>>>>>> >>>>>>>>>> Are you doing system stat collection with munin or ganglia or some >>>>>>>>>> such? >>>>>>>>>> >>>>>>>>>> On Mon, Oct 19, 2009 at 8:25 PM, Ramzi Rabah <rra...@playdom.com> >>>>>>>>>> wrote: >>>>>>>>>>> Hi Jonathan I updated to 4.1 and I still get the same exception >>>>>>>>>>> when I >>>>>>>>>>> call get_key_range. >>>>>>>>>>> I checked all the server logs, and there is only one exception being >>>>>>>>>>> thrown by whichever server I am connecting to. >>>>>>>>>>> >>>>>>>>>>> Thanks >>>>>>>>>>> Ray >>>>>>>>>>> >>>>>>>>>>> On Mon, Oct 19, 2009 at 4:52 PM, Jonathan Ellis <jbel...@gmail.com> >>>>>>>>>>> wrote: >>>>>>>>>>>> No, it's smart enough to avoid scanning. >>>>>>>>>>>> >>>>>>>>>>>> On Mon, Oct 19, 2009 at 6:49 PM, Ramzi Rabah <rra...@playdom.com> >>>>>>>>>>>> wrote: >>>>>>>>>>>>> Hi Jonathan thanks for the reply, I will update the code to 0.4.1 >>>>>>>>>>>>> and >>>>>>>>>>>>> will check all the logs on all the machines. >>>>>>>>>>>>> Just a simple question, when you do a get_key_range and you >>>>>>>>>>>>> specify "" >>>>>>>>>>>>> and "" for start and end, and the limit is 25, if there are too >>>>>>>>>>>>> many >>>>>>>>>>>>> entries, does it do a scan to find out the start or is it smart >>>>>>>>>>>>> enough >>>>>>>>>>>>> to know what the start key is? >>>>>>>>>>>>> >>>>>>>>>>>>> On Mon, Oct 19, 2009 at 4:42 PM, Jonathan Ellis >>>>>>>>>>>>> <jbel...@gmail.com> wrote: >>>>>>>>>>>>>> You should check the other nodes for potential exceptions >>>>>>>>>>>>>> keeping them >>>>>>>>>>>>>> from replying. >>>>>>>>>>>>>> >>>>>>>>>>>>>> Without seeing that it's hard to say if this is caused by an old >>>>>>>>>>>>>> bug, >>>>>>>>>>>>>> but you should definitely upgrade to 0.4.1 either way :) >>>>>>>>>>>>>> >>>>>>>>>>>>>> On Mon, Oct 19, 2009 at 5:51 PM, Ramzi Rabah >>>>>>>>>>>>>> <rra...@playdom.com> wrote: >>>>>>>>>>>>>>> Hello all, >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> I am running into problems with get_key_range. I have >>>>>>>>>>>>>>> OrderPreservingPartitioner defined in storage-conf.xml and I am >>>>>>>>>>>>>>> using >>>>>>>>>>>>>>> a columnfamily that looks like >>>>>>>>>>>>>>> <ColumnFamily CompareWith="BytesType" >>>>>>>>>>>>>>> Name="DatastoreDeletionSchedule" >>>>>>>>>>>>>>> /> >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> My command is client.get_key_range("Keyspace1", >>>>>>>>>>>>>>> "DatastoreDeletionSchedule", >>>>>>>>>>>>>>> "", "", 25, ConsistencyLevel.ONE); >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> It usually works fine but after a day or so from server writes >>>>>>>>>>>>>>> into >>>>>>>>>>>>>>> this column family, I started getting >>>>>>>>>>>>>>> ERROR [pool-1-thread-36] 2009-10-19 17:24:28,223 Cassandra.java >>>>>>>>>>>>>>> (line >>>>>>>>>>>>>>> 770) Internal error processing get_key_range >>>>>>>>>>>>>>> java.lang.RuntimeException: >>>>>>>>>>>>>>> java.util.concurrent.TimeoutException: >>>>>>>>>>>>>>> Operation timed out. >>>>>>>>>>>>>>> at >>>>>>>>>>>>>>> org.apache.cassandra.service.StorageProxy.getKeyRange(StorageProxy.java:560) >>>>>>>>>>>>>>> at >>>>>>>>>>>>>>> org.apache.cassandra.service.CassandraServer.get_key_range(CassandraServer.java:595) >>>>>>>>>>>>>>> at >>>>>>>>>>>>>>> org.apache.cassandra.service.Cassandra$Processor$get_key_range.process(Cassandra.java:766) >>>>>>>>>>>>>>> at >>>>>>>>>>>>>>> org.apache.cassandra.service.Cassandra$Processor.process(Cassandra.java:609) >>>>>>>>>>>>>>> at >>>>>>>>>>>>>>> org.apache.thrift.server.TThreadPoolServer$WorkerProcess.run(TThreadPoolServer.java:253) >>>>>>>>>>>>>>> at >>>>>>>>>>>>>>> java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:885) >>>>>>>>>>>>>>> at >>>>>>>>>>>>>>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907) >>>>>>>>>>>>>>> at java.lang.Thread.run(Thread.java:619) >>>>>>>>>>>>>>> Caused by: java.util.concurrent.TimeoutException: Operation >>>>>>>>>>>>>>> timed out. >>>>>>>>>>>>>>> at >>>>>>>>>>>>>>> org.apache.cassandra.net.AsyncResult.get(AsyncResult.java:97) >>>>>>>>>>>>>>> at >>>>>>>>>>>>>>> org.apache.cassandra.service.StorageProxy.getKeyRange(StorageProxy.java:556) >>>>>>>>>>>>>>> ... 7 more >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> I still get the timeout exceptions even though the servers have >>>>>>>>>>>>>>> been >>>>>>>>>>>>>>> idle for 2 days. When I restart the cassandra servers, it seems >>>>>>>>>>>>>>> to >>>>>>>>>>>>>>> work fine again. Any ideas what could be wrong? >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> By the way, I am using >>>>>>>>>>>>>>> version:apache-cassandra-incubating-0.4.0-rc2 >>>>>>>>>>>>>>> Not sure if this is fixed in the 0.4.1 version >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> Thanks >>>>>>>>>>>>>>> Ray >>>>>>>>>>>>>>> >>>>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> >
