Koji Kawamura commented on NIFI-3332:

I went ahead and created NIFI-5406 to track the progress of new processors with 
different approach. The WIP code is available here 
[https://github.com/apache/nifi/pull/2876] Thanks

> Bug in ListXXX causes matching timestamps to be ignored on later runs
> ---------------------------------------------------------------------
>                 Key: NIFI-3332
>                 URL: https://issues.apache.org/jira/browse/NIFI-3332
>             Project: Apache NiFi
>          Issue Type: Bug
>          Components: Core Framework
>    Affects Versions: 0.7.1, 1.1.1
>            Reporter: Joe Skora
>            Assignee: Koji Kawamura
>            Priority: Critical
>             Fix For: 1.4.0
>         Attachments: Test-showing-ListFile-timestamp-bug.log, 
> Test-showing-ListFile-timestamp-bug.patch, listfiles.png
> The new state implementation for the ListXXX processors based on 
> AbstractListProcessor creates a race conditions when processor runs occur 
> while a batch of files is being written with the same timestamp.
> The changes to state management dropped tracking of the files processed for a 
> given timestamp.  Without the record of files processed, the remainder of the 
> batch is ignored on the next processor run since their timestamp is not 
> greater than the one timestamp stored in processor state.  With the file 
> tracking it was possible to process files that matched the timestamp exactly 
> and exclude the previously processed files.
> A basic time goes as follows.
>   T0 - system creates or receives batch of files with Tx timestamp where Tx 
> is more than the current timestamp in processor state.
>   T1 - system writes 1st half of Tx batch to the ListFile source directory.
>   T2 - ListFile runs picking up 1st half of Tx batch and stores Tx timestamp 
> in processor state.
>   T3 - system writes 2nd half of Tx batch to ListFile source directory.
>   T4 - ListFile runs ignoring any files with T <= Tx, eliminating 2nd half Tx 
> timestamp batch.
> I've attached a patch[1] for TestListFile.java that adds an instrumented unit 
> test demonstrates the problem and a log[2] of the output from one such run.  
> The test writes 3 files each in two batches with processor runs after each 
> batch.  Batch 2 writes files with timestamps older than, equal to, and newer 
> than the timestamp stored when batch 1 was processed, but only the newer file 
> is picked up.  The older file is correctly ignored but file with the matchin 
> timestamp file should have been processed.
> [1] Test-showing-ListFile-timestamp-bug.patch
> [2] Test-showing-ListFile-timestamp-bug.log

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