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https://issues.apache.org/jira/browse/METRON-322?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15928821#comment-15928821
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ASF GitHub Bot commented on METRON-322:
---------------------------------------
GitHub user mattf-horton opened a pull request:
https://github.com/apache/incubator-metron/pull/481
METRON-322 Global Batching and Flushing
This patch starts by adding "batchTimeout" essentially every place
"batchSize" is used. Since the configuration-related classes are many-layered,
this addition is trivial in many cases.
The flush-on-timeout logic is fairly straightforward. It was implemented by
a refactoring of `BulkWriterComponent` to extract an explicit "flush" from the
"write" logic, and then call flush from Tick Tuple processing in
`BulkMessageWriterBolt`.
The tricky part was figuring out the appropriate setting for
`topology.tick.tuple.freq.secs` if the administrator configures non-default
batchTimeouts. It is necessary to enumerate the batchTimeout settings for all
configured sensorNames, which is implemented in
`IndexingConfigurations::getAllConfiguredTimeouts()`. Then multiple other
factors must be taken into account to determine the allowed and recommended
settings, which is implemented in `BatchTimeoutHelper`. If there are better
ways to accomplish these things, please share your ideas.
For test and review, it may be useful to know that the default value of
`batchTimeout`, and hence for `topology.tick.tuple.freq.secs`, is 14 seconds
(which is the default value of `topology.message.timeout.secs` (30 sec) / 2 -
1).
To unit test this feature, we added `Clock` logic and implemented a
writable `FakeClock`. This may be generally useful for testing other
time-based behavior as we add such functionality.
All configuration issues were done in such a way as to default to "good"
behavior, with no changes needed in current configs of previously installed
systems. In fact, recommended configuration is to leave batchTimeout
unconfigured, or set it to zero, thereby accepting the system calculated
default.
After this patch is reviewed and accepted, similar work needs to be done
for the `ParserWriter`, and possibly other sub-components. That will be in a
separate PR.
It is possible to split this patch into sections related to each of
sub-tasks METRON-516, METRON-577, METRON-329 and METRON-330. Let me know if
you would like me to do so. In the past, people seem to prefer to see a whole
feature development in one PR, even though it gets a little long, so that's the
way I'm submitting this one, for now.
## Pull Request Checklist
Thank you for submitting a contribution to Apache Metron (Incubating).
Please refer to our [Development
Guidelines](https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=61332235)
for the complete guide to follow for contributions.
Please refer also to our [Build Verification
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for complete smoke testing guides.
In order to streamline the review of the contribution we ask you follow
these guidelines and ask you to double check the following:
### For all changes:
- [x] Is there a JIRA ticket associated with this PR? If not one needs to
be created at [Metron
Jira](https://issues.apache.org/jira/browse/METRON/?selectedTab=com.atlassian.jira.jira-projects-plugin:summary-panel).
- [x] Does your PR title start with METRON-XXXX where XXXX is the JIRA
number you are trying to resolve? Pay particular attention to the hyphen "-"
character.
- [x] Has your PR been rebased against the latest commit within the target
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### For code changes:
- [NA] Have you included steps to reproduce the behavior or problem that is
being changed or addressed?
- [x] Have you included steps or a guide to how the change may be verified
and tested manually?
Yes, see the two modified .md files, and the above information.
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executed in the root incubating-metron folder via:
```
mvn -q clean integration-test install && build_utils/verify_licenses.sh
```
- [x] Have you written or updated unit tests and or integration tests to
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- [IN PROCESS] Have you verified the basic functionality of the build by
building and running locally with Vagrant full-dev environment or the
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### For documentation related changes:
- [x] Have you ensured that format looks appropriate for the output in
which it is rendered by building and verifying the site-book?
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/mattf-horton/incubator-metron METRON-322
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/incubator-metron/pull/481.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #481
----
commit c2a700e78143b4c7a143a2b061ffb210cdb2d36f
Author: mattf-horton <[email protected]>
Date: 2017-03-07T01:29:13Z
METRON-322 Global Batching and Flushing
changes for sub-tasks METRON-516 and METRON-577, METRON-329 and METRON-330.
----
> Global Batching and Flushing
> ----------------------------
>
> Key: METRON-322
> URL: https://issues.apache.org/jira/browse/METRON-322
> Project: Metron
> Issue Type: Improvement
> Reporter: Ajay Yadav
> Assignee: Matt Foley
>
> All Writers and other bolts that maintain an internal "batch" queue, need to
> have a timeout flush, to prevent messages from low-volume telemetries from
> sitting in their queues indefinitely. Storm has a timeout value
> (topology.message.timeout.secs) that prevents it from waiting for too long.
> If the Writer does not process the queue before the timeout, then Storm
> recycles the tuples through the topology. This has multiple undesirable
> consequences, including data duplication and waste of compute resources. We
> would like to be able to specify an interval after which the queues would
> flush, even if the batch size is not met.
> We will utilize the Storm Tick Tuple to trigger timeout flushing, following
> the recommendations of the article at
> http://hortonworks.com/blog/apache-storm-design-pattern-micro-batching/#CONCLUSION
> Since every Writer processes its queue somewhat differently, every bolt that
> has a "batchSize" parameter will be given a "batchTimeout" parameter too. It
> will default to 1/2 the value of "topology.message.timeout.secs", as
> recommended, and will ignore settings larger than the default, which could
> cause failure to flush in time. In the Enrichment topology, where two
> Writers may be placed one after the other (enrichment and threat intel), the
> default timeout interval will be 1/4 the value of
> "topology.message.timeout.secs". The default value of
> "topology.message.timeout.secs" in Storm is 30 seconds.
> In addition, Storm provides a limit on the number of pending messages that
> have not been acked. If more than "topology.max.spout.pending" messages are
> waiting in a topology, then Storm will recycle them through the topology.
> However, the default value of "topology.max.spout.pending" is null, and if
> set to non-null value, the user can manage the consequences by setting
> batchSize limits appropriately. Having the timeout flush will also
> ameliorate this issue. So we do not need to address
> "topology.max.spout.pending" directly in this task.
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