Sudden errors with backed

[Giuseppe Profiti]

Hello everyone,

I was happily working with a local installation of Titan 0.5.0 up until two days ago. I got exceptions about the backed, then I tried using version 0.5.1 to no avail.

Accessing the graph via Rexter and the dog house is possible, so I suppose there are no problems with my configuration. Also, all the operations went well up until a couple of days ago.

I'm loading a huge amount of edges using the batch mode, but I get exceptions when committing them.

Example:

1    [main] ERROR com.thinkaurelius.titan.graphdb.database.StandardTitanGraph  - Could not commit transaction [1] due to exception
com.thinkaurelius.titan.core.TitanException: Could not execute operation due to backend exception
        at com.thinkaurelius.titan.diskstorage.util.BackendOperation.execute(BackendOperation.java:44)
        at com.thinkaurelius.titan.diskstorage.keycolumnvalue.cache.CacheTransaction.persist(CacheTransaction.java:86)
        at com.thinkaurelius.titan.diskstorage.keycolumnvalue.cache.CacheTransaction.flushInternal(CacheTransaction.java:134)
        at com.thinkaurelius.titan.diskstorage.keycolumnvalue.cache.CacheTransaction.mutate(CacheTransaction.java:81)
        at com.thinkaurelius.titan.diskstorage.keycolumnvalue.cache.KCVSCache.mutateEntries(KCVSCache.java:53)
        at com.thinkaurelius.titan.diskstorage.BackendTransaction.mutateEdges(BackendTransaction.java:184)
        at com.thinkaurelius.titan.graphdb.database.StandardTitanGraph.prepareCommit(StandardTitanGraph.java:498)
        at com.thinkaurelius.titan.graphdb.database.StandardTitanGraph.commit(StandardTitanGraph.java:609)
        at com.thinkaurelius.titan.graphdb.transaction.StandardTitanTx.commit(StandardTitanTx.java:1228)
        at com.thinkaurelius.titan.graphdb.blueprints.TitanBlueprintsGraph.commit(TitanBlueprintsGraph.java:57)
        [my code here]

Caused by: com.thinkaurelius.titan.diskstorage.PermanentBackendException: Permanent failure in storage backend

        at com.thinkaurelius.titan.diskstorage.cassandra.thrift.CassandraThriftKeyColumnValueStore.convertException(CassandraThriftKeyColumnValueStore.java:249)

        at com.thinkaurelius.titan.diskstorage.cassandra.thrift.CassandraThriftStoreManager.mutateMany(CassandraThriftStoreManager.java:314)

        at com.thinkaurelius.titan.diskstorage.locking.consistentkey.ExpectedValueCheckingStoreManager.mutateMany(ExpectedValueCheckingStoreManager.java:64)

        at com.thinkaurelius.titan.diskstorage.keycolumnvalue.cache.CacheTransaction$1.call(CacheTransaction.java:89)

        at com.thinkaurelius.titan.diskstorage.keycolumnvalue.cache.CacheTransaction$1.call(CacheTransaction.java:86)

        at com.thinkaurelius.titan.diskstorage.util.BackendOperation.executeDirect(BackendOperation.java:56)

        at com.thinkaurelius.titan.diskstorage.util.BackendOperation.execute(BackendOperation.java:42)

        ... 12 more

Caused by: TimedOutException(acknowledged_by:0, acknowledged_by_batchlog:false)

        at org.apache.cassandra.thrift.Cassandra$atomic_batch_mutate_result$atomic_batch_mutate_resultStandardScheme.read(Cassandra.java:29454)

        at org.apache.cassandra.thrift.Cassandra$atomic_batch_mutate_result$atomic_batch_mutate_resultStandardScheme.read(Cassandra.java:29422)

        at org.apache.cassandra.thrift.Cassandra$atomic_batch_mutate_result.read(Cassandra.java:29356)

        at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:78)

        at org.apache.cassandra.thrift.Cassandra$Client.recv_atomic_batch_mutate(Cassandra.java:1099)

        at org.apache.cassandra.thrift.Cassandra$Client.atomic_batch_mutate(Cassandra.java:1085)

        at com.thinkaurelius.titan.diskstorage.cassandra.thrift.CassandraThriftStoreManager.mutateMany(CassandraThriftStoreManager.java:309)

        ... 17 more

Exception in thread "main" com.thinkaurelius.titan.core.TitanException: Could not commit transaction due to exception during persistence

        at com.thinkaurelius.titan.graphdb.transaction.StandardTitanTx.commit(StandardTitanTx.java:1239)

        at com.thinkaurelius.titan.graphdb.blueprints.TitanBlueprintsGraph.commit(TitanBlueprintsGraph.java:57)

I'm running a script that executes my code sequentially on different data files and I get this exception, but if I run my code only on the first file, everything works fine.

Any suggestion?

As a side note, the gramlin interface in version 0.5.1 keep raising an error while trying to open the graph:

gremlin> g = TitanFractory.open('conf/bar.properties')

No such property: TitanFractory for class: groovysh_evaluate

Thanks in advance,

Giuseppe

[Jean-Baptiste Musso]

Hi Giuseppe

 

As a side note, the gramlin interface in version 0.5.1 keep raising an error while trying to open the graph:
gremlin> g = TitanFractory.open('conf/bar.properties')
No such property: TitanFractory for class: groovysh_evaluate

There's a small typo here, it should be TitanFactory.open('conf/bar.properties')

This should explain the second issue you're having.

Jean-Baptiste

[Giuseppe Profiti]

Thank you Jean-Baptiste, I missed that typo. However, typing it correctly leads to something that may be related to the main issue:

gremlin> g = TitanFactory.open('conf/bar.properties')
java.lang.ExceptionInInitializerError
Display stack trace? [yN] y
java.lang.ExceptionInInitializerError
        at com.thinkaurelius.titan.diskstorage.Backend$5.<init>(Backend.java:559)
        at com.thinkaurelius.titan.diskstorage.Backend.<clinit>(Backend.java:558)
        at com.thinkaurelius.titan.core.TitanFactory.getLocalConfiguration(TitanFactory.java:173)
        at com.thinkaurelius.titan.core.TitanFactory.open(TitanFactory.java:60)
        at com.thinkaurelius.titan.core.TitanFactory$open.call(Unknown Source)
        [... more stuffin the stack ...]

However, I just finished another single run of the java app that uploads the data and it went without a problem. So I still struggle to identify what could be the backend problem, since it is not consistent.

Thanks,

Giuseppe

[Matthias Broecheler]

Can you show us the full stack trace? The crucial information is missing.

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