[
https://issues.apache.org/jira/browse/IMPALA-14069?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17951536#comment-17951536
]
ASF subversion and git services commented on IMPALA-14069:
----------------------------------------------------------
Commit bc0de109668934e2feb4f3f8fa83c335eabe80ba in impala's branch
refs/heads/master from Surya Hebbar
[ https://gitbox.apache.org/repos/asf?p=impala.git;h=bc0de1096 ]
IMPALA-14069: Factor possibility of zero timestamps in aggregated event
sequences
Currently, the missing event timestamps are substituted by zeros
and then reported(i.e. unreported_event_instance_idxs) within
event sequences of the JSON profile. See IMPALA-13555 for more details.
Even with micro/nanosecond precision, some event timestamps are recorded
as zeros (i.e. Prepare Finished - 0ns).
The current implementation of aggregated event sequences was incorrectly
considering these zeros as substituted missing timestamps.
Although, these can be distinguished from missing timestamps through
the exposed 'unreported_event_instance_idxs', it is more helpful
to represent missing values as -ve values or constants(i.e. -1).
This representation is favorable for summary and visualization, and is
necessary for skipping missing values and maintaing alignment between
instance timestamps.
The patch also fixes null values in "info_strings" fields within
the JSON profile.
Fixed runtime-profile-test to consider -ve values(i.e. -1) as missing
event timestamps, instead of 0.
Updated the generated profiles in testdata/impala-profiles.
Change-Id: I9f1efd2aad5f62084075cd8f9169ef72c66942b6
Reviewed-on: http://gerrit.cloudera.org:8080/22893
Reviewed-by: Riza Suminto <[email protected]>
Tested-by: Riza Suminto <[email protected]>
> Factor possibility of zero timestamps in aggregated event sequences
> -------------------------------------------------------------------
>
> Key: IMPALA-14069
> URL: https://issues.apache.org/jira/browse/IMPALA-14069
> Project: IMPALA
> Issue Type: Bug
> Reporter: Surya Hebbar
> Assignee: Surya Hebbar
> Priority: Major
>
> Currently, the missing event timestamps are reported(i.e.
> unreported_event_instance_idxs) and then substituted by zeros within the JSON
> profile.
> Even with micro/nanosecond precision some event timestamps are still recorded
> as zeros (i.e. Prepare Finished - 0ns).
> These timestamps need to be distinguished from missing timestamps substituted
> with zeros(0).
> But, skipping missing values and loosing alignment between instance
> timestamps is not favorable for summary, representation or visualization.
> So, the aggregated event sequence timestamps should distinguish between both
> types of timestamps by value(i.e. other than existing
> unreported_event_instance_idxs)
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
