Re: com.datastax.driver.core.exceptions.BusyPoolException with CQL backend


Scott P <scott_p...@...>
 

I think I am iterating all the results but I'm not certain. I looked through my traversal code and categorized it into one of these three.

a) Most of my traversals end with toList() or iterate(), such as these.
JanusGraph.traversal().V().has("propA", "value1").has("propB", graphUrl).hasLabel("label1").toList()
JanusGraph.traversal().V().has("propB", "value2").hasLabel("label2").property("propC", "value3").drop().iterate()

b) There are a couple of snippets where I already have a Vertex object and I do g.V(v).next(). I was expecting that a lookup by a Vertex object will only have 1 single result, so it's okay to just call next()
Vertex v = input;
JanusGraph.traversal().V(v).next()

c) And I found a couple suspect snippets where I am ending the traversal with hasNext() to check if something exists.
JanusGraph.traversal().V().has("propD", "value4").hasLabel("label3").hasNext()

Could any of these be leaking a connection?


On Wednesday, August 30, 2017 at 1:21:03 PM UTC-4, Robert Dale wrote:
Are you iterating your results all the way out?

Robert Dale

On Wed, Aug 30, 2017 at 12:52 PM, Jason Plurad <p...@...> wrote:
Looks like you can set a batch size, and the default is 20. Let us know if it helps.

storage.cql.batch-statement-size=20

Related reading on the Cassandra Java Driver FAQ.



On Wednesday, August 30, 2017 at 12:29:36 PM UTC-4, scott_patterson wrote:
I'm trying out the new storage.backend=CQL with cassandra from the master branch (0.2.0) and I'm consistently hitting this error after a few hours of CRUD operations, which could previously be handled (0.1.0) with no problems using the storage.backend=cassandra driver.

Is this a known issue that will be addressed in the final 0.2.0 release? Any recommendations on configuration options to adjust the pool or connection sizes?

org.janusgraph.core.JanusGraphException: Could not execute operation due to backend exception
at org.janusgraph.diskstorage.util.BackendOperation.execute(BackendOperation.java:57)
at org.janusgraph.diskstorage.keycolumnvalue.cache.CacheTransaction.persist(CacheTransaction.java:95)
at org.janusgraph.diskstorage.keycolumnvalue.cache.CacheTransaction.flushInternal(CacheTransaction.java:137)
at org.janusgraph.diskstorage.keycolumnvalue.cache.CacheTransaction.commit(CacheTransaction.java:200)
at org.janusgraph.diskstorage.BackendTransaction.commitStorage(BackendTransaction.java:133)
at org.janusgraph.graphdb.database.StandardJanusGraph.commit(StandardJanusGraph.java:729)
at org.janusgraph.graphdb.transaction.StandardJanusGraphTx.commit(StandardJanusGraphTx.java:1374)
at org.janusgraph.graphdb.tinkerpop.JanusGraphBlueprintsGraph$GraphTransaction.doCommit(JanusGraphBlueprintsGraph.java:272)
at org.apache.tinkerpop.gremlin.structure.util.AbstractTransaction.commit(AbstractTransaction.java:105)
... 13 more
Caused by: org.janusgraph.diskstorage.TemporaryBackendException: Could not successfully complete backend operation due to repeated temporary exceptions after PT1M40S
at org.janusgraph.diskstorage.util.BackendOperation.executeDirect(BackendOperation.java:101)
at org.janusgraph.diskstorage.util.BackendOperation.execute(BackendOperation.java:55)
... 21 more
Caused by: org.janusgraph.diskstorage.TemporaryBackendException: Temporary failure in storage backend
at org.janusgraph.diskstorage.cql.CQLKeyColumnValueStore.lambda$null$2(CQLKeyColumnValueStore.java:123)
at org.janusgraph.diskstorage.cql.CQLKeyColumnValueStore$$Lambda$184.00000000BC05D670.apply(Unknown Source)
at io.vavr.API$Match$Case0.apply(API.java:3174)
at io.vavr.API$Match.of(API.java:3137)
at org.janusgraph.diskstorage.cql.CQLKeyColumnValueStore.lambda$static$3(CQLKeyColumnValueStore.java:120)
at org.janusgraph.diskstorage.cql.CQLKeyColumnValueStore$$Lambda$65.00000000C02B77E0.apply(Unknown Source)
at org.janusgraph.diskstorage.cql.CQLStoreManager.mutateManyUnlogged(CQLStoreManager.java:415)
at org.janusgraph.diskstorage.cql.CQLStoreManager.mutateMany(CQLStoreManager.java:346)
at org.janusgraph.diskstorage.locking.consistentkey.ExpectedValueCheckingStoreManager.mutateMany(ExpectedValueCheckingStoreManager.java:79)
at org.janusgraph.diskstorage.keycolumnvalue.cache.CacheTransaction$1.call(CacheTransaction.java:98)
at org.janusgraph.diskstorage.keycolumnvalue.cache.CacheTransaction$1.call(CacheTransaction.java:95)
at org.janusgraph.diskstorage.util.BackendOperation.executeDirect(BackendOperation.java:69)
... 22 more
Caused by: java.util.concurrent.ExecutionException: com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: /x.x.x.x:9042 (com.datastax.driver.core.exceptions.BusyPoolException: [/x.x.x.x] Pool is busy (no available connection and the queue has reached its max size 256)))
at com.google.common.util.concurrent.AbstractFuture$Sync.getValue(AbstractFuture.java:299)
at com.google.common.util.concurrent.AbstractFuture$Sync.get(AbstractFuture.java:286)
at com.google.common.util.concurrent.AbstractFuture.get(AbstractFuture.java:116)
at io.vavr.concurrent.Future$$Lambda$71.00000000C00F2990.apply(Unknown Source)
at io.vavr.control.Try.of(Try.java:62)
at io.vavr.concurrent.FutureImpl.lambda$run$2(FutureImpl.java:199)
at io.vavr.concurrent.FutureImpl$$Lambda$72.00000000C00F3670.run(Unknown Source)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:522)
... 4 more
Caused by: com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: /x.x.x.x:9042 (com.datastax.driver.core.exceptions.BusyPoolException: [/x.x.x.x] Pool is busy (no available connection and the queue has reached its max size 256)))
at com.datastax.driver.core.RequestHandler.reportNoMoreHosts(RequestHandler.java:211)
at com.datastax.driver.core.RequestHandler.access$1000(RequestHandler.java:46)
at com.datastax.driver.core.RequestHandler$SpeculativeExecution.findNextHostAndQuery(RequestHandler.java:275)
at com.datastax.driver.core.RequestHandler$SpeculativeExecution$1.onFailure(RequestHandler.java:338)
at com.google.common.util.concurrent.Futures$6.run(Futures.java:1310)
at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:457)
at com.google.common.util.concurrent.Futures$ImmediateFuture.addListener(Futures.java:106)
at com.google.common.util.concurrent.Futures.addCallback(Futures.java:1322)
at com.google.common.util.concurrent.Futures.addCallback(Futures.java:1258)
at com.datastax.driver.core.RequestHandler$SpeculativeExecution.query(RequestHandler.java:297)
at com.datastax.driver.core.RequestHandler$SpeculativeExecution.findNextHostAndQuery(RequestHandler.java:272)
at com.datastax.driver.core.RequestHandler.startNewExecution(RequestHandler.java:115)
at com.datastax.driver.core.RequestHandler.sendRequest(RequestHandler.java:95)
at com.datastax.driver.core.SessionManager.executeAsync(SessionManager.java:132)
at org.janusgraph.diskstorage.cql.CQLStoreManager.lambda$null$24(CQLStoreManager.java:406)
at org.janusgraph.diskstorage.cql.CQLStoreManager$$Lambda$106.00000000C0938C00.apply(Unknown Source)
at io.vavr.collection.Iterator$35.getNext(Iterator.java:1632)
at io.vavr.collection.AbstractIterator.next(AbstractIterator.java:34)
at io.vavr.collection.Iterator$34.getNext(Iterator.java:1510)
at io.vavr.collection.AbstractIterator.next(AbstractIterator.java:34)
at io.vavr.collection.Iterator$34.getNext(Iterator.java:1510)
at io.vavr.collection.AbstractIterator.next(AbstractIterator.java:34)
at io.vavr.collection.Traversable.foldLeft(Traversable.java:471)
at io.vavr.concurrent.Future.sequence(Future.java:549)
at org.janusgraph.diskstorage.cql.CQLStoreManager.mutateManyUnlogged(CQLStoreManager.java:388)
at org.janusgraph.diskstorage.cql.CQLStoreManager.mutateMany(CQLStoreManager.java:346)
at org.janusgraph.diskstorage.locking.consistentkey.ExpectedValueCheckingStoreManager.mutateMany(ExpectedValueCheckingStoreManager.java:79)
at org.janusgraph.diskstorage.keycolumnvalue.cache.CacheTransaction$1.call(CacheTransaction.java:98)
at org.janusgraph.diskstorage.keycolumnvalue.cache.CacheTransaction$1.call(CacheTransaction.java:95)
at org.janusgraph.diskstorage.util.BackendOperation.executeDirect(BackendOperation.java:69)
at org.janusgraph.diskstorage.util.BackendOperation.execute(BackendOperation.java:55)
at org.janusgraph.diskstorage.keycolumnvalue.cache.CacheTransaction.persist(CacheTransaction.java:95)
at org.janusgraph.diskstorage.keycolumnvalue.cache.CacheTransaction.flushInternal(CacheTransaction.java:137)
at org.janusgraph.diskstorage.keycolumnvalue.cache.CacheTransaction.commit(CacheTransaction.java:200)
at org.janusgraph.diskstorage.BackendTransaction.commitStorage(BackendTransaction.java:133)
at org.janusgraph.graphdb.database.StandardJanusGraph.commit(StandardJanusGraph.java:729)
at org.janusgraph.graphdb.transaction.StandardJanusGraphTx.commit(StandardJanusGraphTx.java:1374)
at org.janusgraph.graphdb.tinkerpop.JanusGraphBlueprintsGraph$GraphTransaction.doCommit(JanusGraphBlueprintsGraph.java:272)
at org.apache.tinkerpop.gremlin.structure.util.AbstractTransaction.commit(AbstractTransaction.java:105)
... 13 more

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