Damien Obrist created JENA-1619:
-----------------------------------
Summary: TransactionException for large query results
Key: JENA-1619
URL: https://issues.apache.org/jira/browse/JENA-1619
Project: Apache Jena
Issue Type: Bug
Components: TDB2
Affects Versions: Jena 3.9.0
Environment: MacOS 10.14
Java 1.8.0_161 (Oracle)
Reporter: Damien Obrist
Attachments: jena-transaction-exception-master.zip
When querying a TDB2 dataset, I'm observing a suspicious
{{TransactionException}}, even though the query results have been copied so
they can be used outside of a transaction. The exception only seems to occur
when there are many results.
h3. Reproduction steps
* Sample dataset containing 1'000'000 triples
* Query all triples:
{code:java}
SELECT * WHERE { ?s ?p ?o . }{code}
* Copy query results for use outside of transaction:
{code:java}
ResultSetFactory.copyResults(queryExecution.execSelect());{code}
* Get any variable of the first result
All variables are {{null}} and the log shows the following exception:
{noformat}
org.apache.jena.dboe.transaction.txn.TransactionException: Not in a transaction
at
org.apache.jena.dboe.transaction.txn.TransactionalComponentLifecycle.checkTxn(TransactionalComponentLifecycle.java:417)
at
org.apache.jena.dboe.trans.data.TransBinaryDataFile.read(TransBinaryDataFile.java:182)
at
org.apache.jena.tdb2.store.nodetable.TReadAppendFileTransport.read(TReadAppendFileTransport.java:71)
at org.apache.thrift.transport.TTransport.readAll(TTransport.java:86)
at
org.apache.thrift.protocol.TCompactProtocol.readByte(TCompactProtocol.java:637)
at
org.apache.thrift.protocol.TCompactProtocol.readFieldBegin(TCompactProtocol.java:543)
at org.apache.thrift.TUnion$TUnionStandardScheme.read(TUnion.java:222)
at org.apache.thrift.TUnion$TUnionStandardScheme.read(TUnion.java:213)
at org.apache.thrift.TUnion.read(TUnion.java:138)
at
org.apache.jena.tdb2.store.nodetable.NodeTableTRDF.readNodeFromTable(NodeTableTRDF.java:80)
at
org.apache.jena.tdb2.store.nodetable.NodeTableNative._retrieveNodeByNodeId(NodeTableNative.java:103)
at
org.apache.jena.tdb2.store.nodetable.NodeTableNative.getNodeForNodeId(NodeTableNative.java:52)
at
org.apache.jena.tdb2.store.nodetable.NodeTableCache._retrieveNodeByNodeId(NodeTableCache.java:197)
at
org.apache.jena.tdb2.store.nodetable.NodeTableCache.getNodeForNodeId(NodeTableCache.java:108)
at
org.apache.jena.tdb2.store.nodetable.NodeTableWrapper.getNodeForNodeId(NodeTableWrapper.java:52)
at
org.apache.jena.tdb2.store.nodetable.NodeTableInline.getNodeForNodeId(NodeTableInline.java:66)
at org.apache.jena.tdb2.solver.BindingTDB.get1(BindingTDB.java:126)
at
org.apache.jena.sparql.engine.binding.BindingBase.get(BindingBase.java:104)
at org.apache.jena.sparql.core.ResultBinding._get(ResultBinding.java:57)
at
org.apache.jena.sparql.core.QuerySolutionBase.get(QuerySolutionBase.java:33)
at TransactionException.main(TransactionException.java:27)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:282)
at java.lang.Thread.run(Thread.java:748)
{noformat}
I have created a minimal example available on
[GitHub|https://github.com/dobrist/jena-transaction-exception] and attached to
this issue.
h3. Findings
* The exception doesn't occur for smaller query results
* This seems to be a regression as it works as expected with Jena 3.8.0
* Using {{git bisect}} I have identified the commit where this starts to
happen:
[9a60253|https://github.com/apache/jena/commit/9a60253c00aec6763adbb0253588fe4dc0b484d4]
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