[jira] [Commented] (FLINK-10531) State TTL RocksDb backend end-to-end test failed on Travis

["Kostas Kloudas (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/FLINK-10531?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16676957#comment-16676957 ] 

Kostas Kloudas commented on FLINK-10531:
----------------------------------------

It is a test instability. 

The way the test works is the following. For a given state:
1) it keeps the state with TTL
2) and keeps all the updates to that state irrespective of their timestamp (e.g. all the elements added in a ListState)

To verify correctness:
1) it fetches the state from Flink, as cleaned up by the internal TTL mechanism
2) it reconstructs the expected state from the stored updates by taking the timestamp 
   of the latest update (ts) discarding elements with timestamp ts-ttl

As you can see from the stacktrace in the error from Travis, the latest update has timestamp ts=1538918066021
while there are elements in the list with timestamps greater than ts (e.g. 1538918066136). This means that the internal
clock on that machine went backwards, so Flink's TTL may have removed elements that appear in the expected state
of the test, as it takes as current timestamp the ts=1538918066021.

The fix is simply to assume that (for the test), processing time increases monotonically and ignore "updates from the past".

> State TTL RocksDb backend end-to-end test failed on Travis
> ----------------------------------------------------------
>
>                 Key: FLINK-10531
>                 URL: https://issues.apache.org/jira/browse/FLINK-10531
>             Project: Flink
>          Issue Type: Bug
>          Components: Tests
>    Affects Versions: 1.6.1
>            Reporter: Till Rohrmann
>            Assignee: Kostas Kloudas
>            Priority: Critical
>              Labels: test-stability
>
> The {{State TTL RocksDb backend end-to-end test}} end-to-end test failed on Travis.
> https://travis-ci.org/apache/flink/jobs/438226190
> https://api.travis-ci.org/v3/job/438226190/log.txt



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)