On Dec 14, 2010, at 18:45, Nate McCall wrote:
> Timo,
> Apologies if I missed it above, but how big is the batch size you are
> sending to batch_mutate?
Actually only a single row at a time for now (hector 0.7-21):
final Cluster cluster = HFactory.getOrCreateCluster("Test",
cassandraHostConfigurator);
final Keyspace ks = HFactory.createKeyspace("test", cluster);
final Mutator<String> mutator = HFactory.createMutator(ks,
StringSerializer.get());
mutator.addInsertion(id, "tracking", HFactory.createStringColumn("key",
name))
.addInsertion(id, "tracking", HFactory.createStringColumn("value",
value))
.execute();
Thinking of CASSANDRA-475 (this was also OOM, IIRC), is it possibly a
hector/thrift bug?
> On Tue, Dec 14, 2010 at 9:15 AM, Timo Nentwig <timo.nent...@toptarif.de>
> wrote:
>> On Dec 14, 2010, at 15:31, Timo Nentwig wrote:
>>
>>> On Dec 14, 2010, at 14:41, Jonathan Ellis wrote:
>>>
>>>> This is "A row has grown too large" section from that troubleshooting
>>>> guide.
>>>
>>> Why? This is what a typical "row" (?) looks like:
>>>
>>> [defa...@test] list tracking limit 1;
>>> -------------------
>>> RowKey: 123
>>> => (column=key, value=foo, timestamp=1292238005886000)
>>> => (column=value, value=bar, timestamp=1292238005886000)
>>>
>>> I'm importing the data from a RDBMS so I can say for sure that none of the
>>> 2 columns will contain more than 255 chars.
>>
>> Started all over again. Deleleted /var/lib/cassandra/*, started 4 nodes
>> (2x2G+2x1G heap, actual RAM twice as much, swap off) and my stress test:
>> first node (1GB) crashed after 212s (!). Wrote roughly about 200k rows like
>> the one above (data wasn't even flushed to disk!).
>>
>> INFO [main] 2010-12-14 15:58:23,938 CassandraDaemon.java (line 119)
>> Listening for thrift clients...
>> INFO [GossipStage:1] 2010-12-14 15:58:24,410 Gossiper.java (line 569)
>> InetAddress /192.168.68.80 is now UP
>> INFO [HintedHandoff:1] 2010-12-14 15:58:24,410 HintedHandOffManager.java
>> (line 191) Started hinted handoff for endpoint /192.168.68.80
>> INFO [HintedHandoff:1] 2010-12-14 15:58:24,412 HintedHandOffManager.java
>> (line 247) Finished hinted handoff of 0 rows to endpoint /192.168.68.80
>> INFO [GossipStage:1] 2010-12-14 15:58:26,335 Gossiper.java (line 577) Node
>> /192.168.68.69 is now part of the cluster
>> INFO [GossipStage:1] 2010-12-14 15:58:27,319 Gossiper.java (line 569)
>> InetAddress /192.168.68.69 is now UP
>> INFO [HintedHandoff:1] 2010-12-14 15:58:27,319 HintedHandOffManager.java
>> (line 191) Started hinted handoff for endpoint /192.168.68.69
>> INFO [HintedHandoff:1] 2010-12-14 15:58:27,320 HintedHandOffManager.java
>> (line 247) Finished hinted handoff of 0 rows to endpoint /192.168.68.69
>> INFO [GossipStage:1] 2010-12-14 15:58:29,446 Gossiper.java (line 577) Node
>> /192.168.68.70 is now part of the cluster
>> INFO [GossipStage:1] 2010-12-14 15:58:29,620 Gossiper.java (line 569)
>> InetAddress /192.168.68.70 is now UP
>> INFO [HintedHandoff:1] 2010-12-14 15:58:29,621 HintedHandOffManager.java
>> (line 191) Started hinted handoff for endpoint /192.168.68.70
>> INFO [HintedHandoff:1] 2010-12-14 15:58:29,621 HintedHandOffManager.java
>> (line 247) Finished hinted handoff of 0 rows to endpoint /192.168.68.70
>> INFO [MigrationStage:1] 2010-12-14 16:01:16,535 ColumnFamilyStore.java
>> (line 639) switching in a fresh Memtable for Migrations at
>> CommitLogContext(file='/var/lib/cassandra/commitlog/CommitLog-1292338703483.log',
>> position=15059)
>> INFO [MigrationStage:1] 2010-12-14 16:01:16,536 ColumnFamilyStore.java
>> (line 943) Enqueuing flush of memtable-migrati...@768974140(9092 bytes, 1
>> operations)
>> INFO [MigrationStage:1] 2010-12-14 16:01:16,536 ColumnFamilyStore.java
>> (line 639) switching in a fresh Memtable for Schema at
>> CommitLogContext(file='/var/lib/cassandra/commitlog/CommitLog-1292338703483.log',
>> position=15059)
>> INFO [MigrationStage:1] 2010-12-14 16:01:16,536 ColumnFamilyStore.java
>> (line 943) Enqueuing flush of memtable-sch...@591783334(3765 bytes, 3
>> operations)
>> INFO [FlushWriter:1] 2010-12-14 16:01:16,541 Memtable.java (line 155)
>> Writing memtable-migrati...@768974140(9092 bytes, 1 operations)
>> INFO [FlushWriter:1] 2010-12-14 16:01:16,633 Memtable.java (line 162)
>> Completed flushing /var/lib/cassandra/data/system/Migrations-e-1-Data.db
>> (9225 bytes)
>> INFO [FlushWriter:1] 2010-12-14 16:01:16,634 Memtable.java (line 155)
>> Writing memtable-sch...@591783334(3765 bytes, 3 operations)
>> INFO [FlushWriter:1] 2010-12-14 16:01:16,706 Memtable.java (line 162)
>> Completed flushing /var/lib/cassandra/data/system/Schema-e-1-Data.db (4053
>> bytes)
>> INFO [Create index Indexed1.626972746864617465] 2010-12-14 16:01:16,718
>> ColumnFamilyStore.java (line 325) Creating index
>> org.apache.cassandra.db.ta...@354d581b.indexed1.626972746864617465
>> INFO [MigrationStage:1] 2010-12-14 16:01:16,725 ColumnFamilyStore.java
>> (line 639) switching in a fresh Memtable for Migrations at
>> CommitLogContext(file='/var/lib/cassandra/commitlog/CommitLog-1292338703483.log',
>> position=27559)
>> INFO [MigrationStage:1] 2010-12-14 16:01:16,726 ColumnFamilyStore.java
>> (line 943) Enqueuing flush of memtable-migrati...@1922556837(7973 bytes, 1
>> operations)
>> INFO [Create index Indexed1.626972746864617465] 2010-12-14 16:01:16,729
>> ColumnFamilyStore.java (line 339) Index Indexed1.626972746864617465 complete
>> INFO [MigrationStage:1] 2010-12-14 16:01:16,730 ColumnFamilyStore.java
>> (line 639) switching in a fresh Memtable for Schema at
>> CommitLogContext(file='/var/lib/cassandra/commitlog/CommitLog-1292338703483.log',
>> position=27559)
>> INFO [FlushWriter:1] 2010-12-14 16:01:16,730 Memtable.java (line 155)
>> Writing memtable-migrati...@1922556837(7973 bytes, 1 operations)
>> INFO [MigrationStage:1] 2010-12-14 16:01:16,730 ColumnFamilyStore.java
>> (line 943) Enqueuing flush of memtable-sch...@1373806697(4029 bytes, 4
>> operations)
>> INFO [Create index Indexed1.626972746864617465] 2010-12-14 16:01:16,733
>> ColumnFamilyStore.java (line 639) switching in a fresh Memtable for
>> IndexInfo at
>> CommitLogContext(file='/var/lib/cassandra/commitlog/CommitLog-1292338703483.log',
>> position=27707)
>> INFO [Create index Indexed1.626972746864617465] 2010-12-14 16:01:16,734
>> ColumnFamilyStore.java (line 943) Enqueuing flush of
>> memtable-indexi...@1972467582(42 bytes, 1 operations)
>> INFO [FlushWriter:1] 2010-12-14 16:01:16,808 Memtable.java (line 162)
>> Completed flushing /var/lib/cassandra/data/system/Migrations-e-2-Data.db
>> (8106 bytes)
>> INFO [FlushWriter:1] 2010-12-14 16:01:16,816 Memtable.java (line 155)
>> Writing memtable-sch...@1373806697(4029 bytes, 4 operations)
>> INFO [FlushWriter:1] 2010-12-14 16:01:16,902 Memtable.java (line 162)
>> Completed flushing /var/lib/cassandra/data/system/Schema-e-2-Data.db (4317
>> bytes)
>> INFO [FlushWriter:1] 2010-12-14 16:01:16,904 Memtable.java (line 155)
>> Writing memtable-indexi...@1972467582(42 bytes, 1 operations)
>> INFO [FlushWriter:1] 2010-12-14 16:01:16,968 Memtable.java (line 162)
>> Completed flushing /var/lib/cassandra/data/system/IndexInfo-e-1-Data.db (170
>> bytes)
>> ERROR [MutationStage:22] 2010-12-14 16:02:00,283
>> AbstractCassandraDaemon.java (line 90) Fatal exception in thread
>> Thread[MutationStage:22,5,main]
>> java.lang.OutOfMemoryError: Java heap space
>> at java.nio.HeapByteBuffer.<init>(HeapByteBuffer.java:39)
>> at java.nio.ByteBuffer.allocate(ByteBuffer.java:312)
>> at
>> org.apache.cassandra.utils.FBUtilities.readByteArray(FBUtilities.java:261)
>> at
>> org.apache.cassandra.db.ColumnSerializer.deserialize(ColumnSerializer.java:76)
>> at
>> org.apache.cassandra.db.ColumnSerializer.deserialize(ColumnSerializer.java:35)
>> at
>> org.apache.cassandra.db.ColumnFamilySerializer.deserializeColumns(ColumnFamilySerializer.java:129)
>> at
>> org.apache.cassandra.db.ColumnFamilySerializer.deserialize(ColumnFamilySerializer.java:120)
>> at
>> org.apache.cassandra.db.RowMutationSerializer.defreezeTheMaps(RowMutation.java:383)
>> at
>> org.apache.cassandra.db.RowMutationSerializer.deserialize(RowMutation.java:393)
>> at
>> org.apache.cassandra.db.RowMutationSerializer.deserialize(RowMutation.java:351)
>> at
>> org.apache.cassandra.db.RowMutationVerbHandler.doVerb(RowMutationVerbHandler.java:52)
>> at
>> org.apache.cassandra.net.MessageDeliveryTask.run(MessageDeliveryTask.java:63)
>> 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:662)
>>
>> gc:
>>
>> 210.919: [GC 210.919: [ParNew
>> Desired survivor size 2162688 bytes, new threshold 1 (max 1)
>> - age 1: 1833480 bytes, 1833480 total
>> : 16139K->4221K(38336K), 0.0377710 secs]210.957: [CMS:
>> 690490K->171727K(1006016K), 1.0604710 secs] 702251K->171727K(1044352K), [CMS
>> Perm : 17750K->17734K(21248K)], 1.0985490 secs] [Times: user=1.11 sys=0.01,
>> real=1.10 secs]
>> 212.017: [Full GC 212.017: [CMS: 171727K->171315K(1006016K), 1.0312260 secs]
>> 171727K->171315K(1044352K), [CMS Perm : 17734K->17504K(29560K)], 1.0314660
>> secs] [Times: user=1.03 sys=0.00, real=1.03 secs]
>> Total time for which application threads were stopped: 2.1309030 seconds
>> Total time for which application threads were stopped: 4.4463770 seconds
>> Heap
>> par new generation total 38336K, used 15546K [0x00000000bae00000,
>> 0x00000000bd790000, 0x00000000bd790000)
>> eden space 34112K, 45% used [0x00000000bae00000, 0x00000000bbd2ebb8,
>> 0x00000000bcf50000)
>> from space 4224K, 0% used [0x00000000bd370000, 0x00000000bd370000,
>> 0x00000000bd790000)
>> to space 4224K, 0% used [0x00000000bcf50000, 0x00000000bcf50000,
>> 0x00000000bd370000)
>> concurrent mark-sweep generation total 1006016K, used 171315K
>> [0x00000000bd790000, 0x00000000fae00000, 0x00000000fae00000)
>> concurrent-mark-sweep perm gen total 29560K, used 17572K
>> [0x00000000fae00000, 0x00000000fcade000, 0x0000000100000000)
>>
>>
>> During this short time I experienced 4 times (mentioned this already on the
>> dev list):
>>
>> me.prettyprint.hector.api.exceptions.HCassandraInternalException: Cassandra
>> encountered an internal error processing this request: TApplicationError
>> type: 6 message:Internal error processing batch_mutate
>> at
>> me.prettyprint.cassandra.service.ExceptionsTranslatorImpl.translate(ExceptionsTranslatorImpl.java:27)
>> at
>> me.prettyprint.cassandra.service.KeyspaceServiceImpl$1.execute(KeyspaceServiceImpl.java:95)
>> at
>> me.prettyprint.cassandra.service.KeyspaceServiceImpl$1.execute(KeyspaceServiceImpl.java:1)
>> at
>> me.prettyprint.cassandra.service.Operation.executeAndSetResult(Operation.java:89)
>> at
>> me.prettyprint.cassandra.connection.HConnectionManager.operateWithFailover(HConnectionManager.java:142)
>> at
>> me.prettyprint.cassandra.service.KeyspaceServiceImpl.operateWithFailover(KeyspaceServiceImpl.java:129)
>> at
>> me.prettyprint.cassandra.service.KeyspaceServiceImpl.batchMutate(KeyspaceServiceImpl.java:100)
>> at
>> me.prettyprint.cassandra.service.KeyspaceServiceImpl.batchMutate(KeyspaceServiceImpl.java:106)
>> at
>> me.prettyprint.cassandra.model.MutatorImpl$2.doInKeyspace(MutatorImpl.java:149)
>> at
>> me.prettyprint.cassandra.model.MutatorImpl$2.doInKeyspace(MutatorImpl.java:1)
>> at
>> me.prettyprint.cassandra.model.KeyspaceOperationCallback.doInKeyspaceAndMeasure(KeyspaceOperationCallback.java:20)
>> at
>> me.prettyprint.cassandra.model.ExecutingKeyspace.doExecute(ExecutingKeyspace.java:65)
>> at
>> me.prettyprint.cassandra.model.MutatorImpl.execute(MutatorImpl.java:146)
>> at Trackr$3.run(Trackr.java:133)
>> at Trackr$BoundedExecutor$1.run(Trackr.java:167)
>> at
>> java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
>> at
>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
>> at java.lang.Thread.run(Thread.java:680)
>>
>>> That row warning seems to be a 0.6 option, don't find it in 0.7 docs.
>>> Didn't find any related WARNs for some default value in the log also.
>>>
>>>> On Tue, Dec 14, 2010 at 5:27 AM, Timo Nentwig <timo.nent...@toptarif.de>
>>>> wrote:
>>>>
>>>> On Dec 12, 2010, at 17:21, Jonathan Ellis wrote:
>>>>
>>>>> http://www.riptano.com/docs/0.6/troubleshooting/index#nodes-are-dying-with-oom-errors
>>>>
>>>> I can rule out the first 3. I was running cassandra with default settings,
>>>> i.e. 1GB heap and 256M memtable. So, with 3 memtables+1GB the JVM should
>>>> run with >1.75G (although
>>>> http://wiki.apache.org/cassandra/MemtableThresholds considers to increase
>>>> heap size only gently). Did so. 4GB machine with 2GB 64bit-JVM seemed to
>>>> run stable for quite some time but then also crashed with OOM. Looking at
>>>> the heap dump it's always the same: all memory nearly always bound in
>>>> CompactionExecutor (ColumnFamilyStore/ConcurrentSkipListMap, respectively).
>>>>
>>>> This looks like somebody else recently have had a similar problem
>>>> (->Bottom line: more heap - which is okay, but I'd like to understand why):
>>>> http://www.mail-archive.com/user@cassandra.apache.org/msg07516.html
>>>>
>>>> This is my only CF currently in use (via JMX):
>>>>
>>>> - column_families:
>>>> - column_type: Standard
>>>> comment: tracking column family
>>>> compare_with: org.apache.cassandra.db.marshal.UTF8Type
>>>> default_validation_class: org.apache.cassandra.db.marshal.UTF8Type
>>>> gc_grace_seconds: 864000
>>>> key_cache_save_period_in_seconds: 3600
>>>> keys_cached: 200000.0
>>>> max_compaction_threshold: 32
>>>> memtable_flush_after_mins: 60
>>>> min_compaction_threshold: 4
>>>> name: tracking
>>>> read_repair_chance: 1.0
>>>> row_cache_save_period_in_seconds: 0
>>>> rows_cached: 0.0
>>>> name: test
>>>> replica_placement_strategy: org.apache.cassandra.locator.SimpleStrategy
>>>> replication_factor: 3
>>>>
>>>>
>>>> In addition...actually there is plenty of free memory on the heap (?):
>>>>
>>>> 3605.478: [GC 3605.478: [ParNew
>>>> Desired survivor size 2162688 bytes, new threshold 1 (max 1)
>>>> - age 1: 416112 bytes, 416112 total
>>>> : 16887K->553K(38336K), 0.0209550 secs]3605.499: [CMS:
>>>> 1145267K->447565K(2054592K), 1.9143630 secs] 1161938K->447565K(2092928K),
>>>> [CMS Perm : 18186K->18158K(30472K)], 1.9355340 secs] [Times: user=1.95
>>>> sys=0.00, real=1.94 secs]
>>>> 3607.414: [Full GC 3607.414: [CMS: 447565K->447453K(2054592K), 1.9694960
>>>> secs] 447565K->447453K(2092928K), [CMS Perm : 18158K->18025K(30472K)],
>>>> 1.9696450 secs] [Times: user=1.92 sys=0.00, real=1.97 secs]
>>>> Total time for which application threads were stopped: 3.9070380 seconds
>>>> Total time for which application threads were stopped: 7.3388640 seconds
>>>> Total time for which application threads were stopped: 0.0560610 seconds
>>>> 3616.931: [GC 3616.931: [ParNew
>>>> Desired survivor size 2162688 bytes, new threshold 1 (max 1)
>>>> - age 1: 474264 bytes, 474264 total
>>>> : 34112K->747K(38336K), 0.0098680 secs] 481565K->448201K(2092928K),
>>>> 0.0099690 secs] [Times: user=0.00 sys=0.00, real=0.01 secs]
>>>> Total time for which application threads were stopped: 0.0108670 seconds
>>>> 3617.035: [GC 3617.035: [ParNew
>>>> Desired survivor size 2162688 bytes, new threshold 1 (max 1)
>>>> - age 1: 63040 bytes, 63040 total
>>>> : 34859K->440K(38336K), 0.0065950 secs] 482313K->448455K(2092928K),
>>>> 0.0066880 secs] [Times: user=0.00 sys=0.00, real=0.00 secs]
>>>> Total time for which application threads were stopped: 0.0075850 seconds
>>>> 3617.133: [GC 3617.133: [ParNew
>>>> Desired survivor size 2162688 bytes, new threshold 1 (max 1)
>>>> - age 1: 23016 bytes, 23016 total
>>>> : 34552K->121K(38336K), 0.0042920 secs] 482567K->448193K(2092928K),
>>>> 0.0043650 secs] [Times: user=0.01 sys=0.00, real=0.00 secs]
>>>> Total time for which application threads were stopped: 0.0049630 seconds
>>>> 3617.228: [GC 3617.228: [ParNew
>>>> Desired survivor size 2162688 bytes, new threshold 1 (max 1)
>>>> - age 1: 16992 bytes, 16992 total
>>>> : 34233K->34K(38336K), 0.0043180 secs] 482305K->448122K(2092928K),
>>>> 0.0043910 secs] [Times: user=0.00 sys=0.00, real=0.00 secs]
>>>> Total time for which application threads were stopped: 0.0049150 seconds
>>>> 3617.323: [GC 3617.323: [ParNew
>>>> Desired survivor size 2162688 bytes, new threshold 1 (max 1)
>>>> - age 1: 18456 bytes, 18456 total
>>>> : 34146K->29K(38336K), 0.0038930 secs] 482234K->448127K(2092928K),
>>>> 0.0039810 secs] [Times: user=0.00 sys=0.00, real=0.00 secs]
>>>> Total time for which application threads were stopped: 0.0055390 seconds
>>>> Heap
>>>> par new generation total 38336K, used 17865K [0x000000077ae00000,
>>>> 0x000000077d790000, 0x000000077d790000)
>>>> eden space 34112K, 52% used [0x000000077ae00000, 0x000000077bf6afb0,
>>>> 0x000000077cf50000)
>>>> from space 4224K, 0% used [0x000000077cf50000, 0x000000077cf57720,
>>>> 0x000000077d370000)
>>>> to space 4224K, 0% used [0x000000077d370000, 0x000000077d370000,
>>>> 0x000000077d790000)
>>>> concurrent mark-sweep generation total 2054592K, used 448097K
>>>> [0x000000077d790000, 0x00000007fae00000, 0x00000007fae00000)
>>>> concurrent-mark-sweep perm gen total 30472K, used 18125K
>>>> [0x00000007fae00000, 0x00000007fcbc2000, 0x0000000800000000)
>>>>
>>>>>
>>>>> On Sun, Dec 12, 2010 at 9:52 AM, Timo Nentwig <timo.nent...@toptarif.de>
>>>>> wrote:
>>>>>
>>>>> On Dec 10, 2010, at 19:37, Peter Schuller wrote:
>>>>>
>>>>>> To cargo cult it: Are you running a modern JVM? (Not e.g. openjdk b17
>>>>>> in lenny or some such.) If it is a JVM issue, ensuring you're using a
>>>>>> reasonably recent JVM is probably much easier than to start tracking
>>>>>> it down...
>>>>>
>>>>> I had OOM problems with OpenJDK, switched to Sun/Oracle's recent 1.6.0_23
>>>>> and...still have the same problem :-\ Stack trace always looks the same:
>>>>>
>>>>> java.lang.OutOfMemoryError: Java heap space
>>>>> at java.nio.HeapByteBuffer.<init>(HeapByteBuffer.java:57)
>>>>> at java.nio.ByteBuffer.allocate(ByteBuffer.java:329)
>>>>> at
>>>>> org.apache.cassandra.utils.FBUtilities.readByteArray(FBUtilities.java:261)
>>>>> at
>>>>> org.apache.cassandra.db.ColumnSerializer.deserialize(ColumnSerializer.java:76)
>>>>> at
>>>>> org.apache.cassandra.db.ColumnSerializer.deserialize(ColumnSerializer.java:35)
>>>>> at
>>>>> org.apache.cassandra.db.ColumnFamilySerializer.deserializeColumns(ColumnFamilySerializer.java:129)
>>>>> at
>>>>> org.apache.cassandra.db.ColumnFamilySerializer.deserialize(ColumnFamilySerializer.java:120)
>>>>> at
>>>>> org.apache.cassandra.db.RowMutationSerializer.defreezeTheMaps(RowMutation.java:383)
>>>>> at
>>>>> org.apache.cassandra.db.RowMutationSerializer.deserialize(RowMutation.java:393)
>>>>> at
>>>>> org.apache.cassandra.db.RowMutationSerializer.deserialize(RowMutation.java:351)
>>>>> at
>>>>> org.apache.cassandra.db.RowMutationVerbHandler.doVerb(RowMutationVerbHandler.java:52)
>>>>> at
>>>>> org.apache.cassandra.net.MessageDeliveryTask.run(MessageDeliveryTask.java:63)
>>>>> at
>>>>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
>>>>> at
>>>>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
>>>>> at java.lang.Thread.run(Thread.java:636)
>>>>>
>>>>> I'm writing from 1 client with 50 threads to a cluster of 4 machines
>>>>> (with hector). With QUORUM and ONE 2 machines quite reliably will soon
>>>>> die with OOM. What may cause this? Won't cassandra block/reject when
>>>>> memtable is full and being flushed to disk but grow and if flushing to
>>>>> disk isn't fast enough will run out of memory?
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Jonathan Ellis
>>>>> Project Chair, Apache Cassandra
>>>>> co-founder of Riptano, the source for professional Cassandra support
>>>>> http://riptano.com
>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Jonathan Ellis
>>>> Project Chair, Apache Cassandra
>>>> co-founder of Riptano, the source for professional Cassandra support
>>>> http://riptano.com
>>>
>>
>>
