Brandon DeVries created NIFI-5331:
-------------------------------------
Summary: SequentialAccessWriteAheadLog: poisioned journal requires
restart
Key: NIFI-5331
URL: https://issues.apache.org/jira/browse/NIFI-5331
Project: Apache NiFi
Issue Type: Bug
Components: Core Framework
Affects Versions: 1.6.0
Reporter: Brandon DeVries
If using the SequentialAccessWriteAheadLog, once a journal becomes poisoned,
NiFi can't recover without a restart.
SequentialAccessWriteAheadLog uses a LengthDelimitedJournal which has a
"poisoned" flag[1]. This is initially set "false", but is set true if an
Exceptions or Throwable is encountered on a write operation[2]. Once poisoned,
calls to update()[3] will result in a call to checkState()[4] which then throws
an IOException stating, "Cannot update journal file... If the repository is
able to checkpoint, then this problem will resolve itself..."
SequentialAccessWriteAheadLog.checkpoint()[5] creates a new
LengthDelimitedJournal which would hypothetically have a cleared "poisoned"
flag . However, before creating that new Journal, it calls journal.fsync()[6],
which calls checkState(), which throws the above IOException if poisoned ==
true. So, the FlowFileRepository enters a state where it cannot be written to,
and cannot recover, until the instance is restarted.
[1]
[https://github.com/apache/nifi/blob/rel/nifi-1.6.0/nifi-commons/nifi-write-ahead-log/src/main/java/org/apache/nifi/wali/LengthDelimitedJournal.java#L70]
[2]
[https://github.com/apache/nifi/blob/rel/nifi-1.6.0/nifi-commons/nifi-write-ahead-log/src/main/java/org/apache/nifi/wali/LengthDelimitedJournal.java#L208]
[3]
[https://github.com/apache/nifi/blob/rel/nifi-1.6.0/nifi-commons/nifi-write-ahead-log/src/main/java/org/apache/nifi/wali/LengthDelimitedJournal.java#L178]
[4]
[https://github.com/apache/nifi/blob/rel/nifi-1.6.0/nifi-commons/nifi-write-ahead-log/src/main/java/org/apache/nifi/wali/LengthDelimitedJournal.java#L217]
[5]
[https://github.com/apache/nifi/blob/rel/nifi-1.6.0/nifi-commons/nifi-write-ahead-log/src/main/java/org/apache/nifi/wali/SequentialAccessWriteAheadLog.java#L279]
[6]
[https://github.com/apache/nifi/blob/rel/nifi-1.6.0/nifi-commons/nifi-write-ahead-log/src/main/java/org/apache/nifi/wali/SequentialAccessWriteAheadLog.java#L259]
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