Issue with triggers in phase 'after'

[neo-technology-build-agent]

Issue by kraney Tuesday Mar 17, 2020 at 23:49 GMT Originally opened as https://github.com/neo4j-contrib/neo4j-apoc-procedures/issues/1450

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Expected Behavior (Mandatory)

Adding a trigger in phase 'after' does not disrupt any operations

Actual Behavior (Mandatory)

When I create a trigger in phase 'after' - even when I reduce it to simply doing "RETURN NULL", it causes some transactions to fail with a stack trace like the following:

2020-03-17 23:39:53.368+0000 WARN  Error executing trigger onNewDeviceConfig_PublishForModel in phase after Getting deleted relationship data should have been covered by the tx state
java.lang.IllegalStateException: Getting deleted relationship data should have been covered by the tx state
	at org.neo4j.kernel.impl.coreapi.TxStateTransactionDataSnapshot.relationship(TxStateTransactionDataSnapshot.java:354)
	at org.eclipse.collections.impl.lazy.primitive.CollectLongToObjectIterable$2.next(CollectLongToObjectIterable.java:82)
	at org.neo4j.kernel.impl.util.ValueUtils.asListValue(ValueUtils.java:192)
	at org.neo4j.kernel.impl.util.ValueUtils.of(ValueUtils.java:106)
	at org.neo4j.kernel.impl.util.ValueUtils.asParameterMapValue(ValueUtils.java:249)
	at org.neo4j.kernel.impl.factory.GraphDatabaseFacade.execute(GraphDatabaseFacade.java:404)
	at apoc.trigger.Trigger$TriggerHandler.lambda$executeTriggers$0(Trigger.java:282)
	at java.util.concurrent.ConcurrentHashMap.forEach(ConcurrentHashMap.java:1597)
	at apoc.trigger.Trigger$TriggerHandler.executeTriggers(Trigger.java:272)
	at apoc.trigger.Trigger$TriggerHandler.afterCommit(Trigger.java:305)
	at org.neo4j.kernel.internal.TransactionEventHandlers.afterCommit(TransactionEventHandlers.java:149)
	at org.neo4j.kernel.internal.TransactionEventHandlers.afterCommit(TransactionEventHandlers.java:48)
	at org.neo4j.kernel.impl.api.TransactionHooks.afterCommit(TransactionHooks.java:76)
	at org.neo4j.kernel.impl.api.KernelTransactionImplementation.afterCommit(KernelTransactionImplementation.java:922)
	at org.neo4j.kernel.impl.api.KernelTransactionImplementation.commit(KernelTransactionImplementation.java:745)
	at org.neo4j.kernel.impl.api.KernelTransactionImplementation.closeTransaction(KernelTransactionImplementation.java:594)
	at org.neo4j.internal.kernel.api.Transaction.close(Transaction.java:178)
	at org.neo4j.bolt.v1.runtime.TransactionStateMachine$State.closeTransaction(TransactionStateMachine.java:469)
	at org.neo4j.bolt.v1.runtime.TransactionStateMachine$State$2.commitTransaction(TransactionStateMachine.java:402)
	at org.neo4j.bolt.v1.runtime.TransactionStateMachine.commitTransaction(TransactionStateMachine.java:144)
	at org.neo4j.bolt.v3.runtime.TransactionReadyState.processCommitMessage(TransactionReadyState.java:93)
	at org.neo4j.bolt.v3.runtime.TransactionReadyState.processUnsafe(TransactionReadyState.java:53)
	at org.neo4j.bolt.v3.runtime.FailSafeBoltStateMachineState.process(FailSafeBoltStateMachineState.java:48)
	at org.neo4j.bolt.v1.runtime.BoltStateMachineV1.nextState(BoltStateMachineV1.java:144)
	at org.neo4j.bolt.v1.runtime.BoltStateMachineV1.process(BoltStateMachineV1.java:92)
	at org.neo4j.bolt.messaging.BoltRequestMessageReader.lambda$doRead$1(BoltRequestMessageReader.java:89)
	at org.neo4j.bolt.runtime.MetricsReportingBoltConnection.lambda$enqueue$0(MetricsReportingBoltConnection.java:68)
	at org.neo4j.bolt.runtime.DefaultBoltConnection.processNextBatch(DefaultBoltConnection.java:191)
	at org.neo4j.bolt.runtime.MetricsReportingBoltConnection.processNextBatch(MetricsReportingBoltConnection.java:86)
	at org.neo4j.bolt.runtime.DefaultBoltConnection.processNextBatch(DefaultBoltConnection.java:139)
	at org.neo4j.bolt.runtime.ExecutorBoltScheduler.executeBatch(ExecutorBoltScheduler.java:171)
	at org.neo4j.bolt.runtime.ExecutorBoltScheduler.lambda$scheduleBatchOrHandleError$2(ExecutorBoltScheduler.java:154)
	at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1604)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
Caused by: org.neo4j.internal.kernel.api.exceptions.EntityNotFoundException: Unable to load RELATIONSHIP with id 147.
	at org.neo4j.kernel.impl.storageengine.impl.recordstorage.RecordStorageReader.relationshipVisit(RecordStorageReader.java:258)
	at org.neo4j.kernel.impl.coreapi.TxStateTransactionDataSnapshot.relationship(TxStateTransactionDataSnapshot.java:349)
	... 35 more

The specific transactions that fail with this error seem to be ones that include a deleted relationship. And that relationship was itself deleted by a 'before' trigger, if that matters.

How to Reproduce the Problem

I have not yet been able to reduce the problem to a straightforward procedure to reproduce it. It seems to be a complex interaction between triggers.

Steps (Mandatory)

1. Add any trigger to phase 'after'
2. Attempt to execute a transaction that delete a relationship from a 'before' trigger.

Specifications (Mandatory)

Currently used versions

Versions

• OS: Linux
• Neo4j: 3.5.16
• Neo4j-Apoc: 3.5.0.9