capistrant opened a new pull request #10622: URL: https://github.com/apache/druid/pull/10622
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How did you fix the problem? --> <!-- If there are several relatively logically separate changes in this PR, create a mini-section for each of them. For example: --> # Background Some batch ingestion jobs dynamically identify the intervals being ingested as well as the sharding within those intervals. This dynamic discovery is very user friendly. However, we have found, at my company, that on our multi-tenant cluster where many users submit ingestion jobs through a managed service that creates and submits ingestion specs, users can mistakenly start jobs that index more than they or we would like them to index in one job. For instance, a user may try to start a hadoop batch job that indexes a year of raw source data at hourly granularity. This generates up to 365 * 24 = 8,760 intervals that may have even more sharding within intervals. To combat this, we have decided to limit the number of segment intervals that a single HadoopIndexTask or IndexTask can create. We also limit the aggregate number of shards across the whole ingestion job when possible too. Doing so has allowed us to improve quality of service to our many tenants. Now we have decided to explor e upstreaming a similar implementation of our tooling. Our thought is that we will open this PR and gauge the community interest in such a feature. I think others who run multi tenant clusters could benefit from this if merged. # Description of feature These new configs are limited to only IndexTask (non-parallel) and HadoopIndexTask. While we have not fully explored implementation for ParallelIndexTask, it appears that it may be difficult or impossible to find a way to cleanly identify when and how to stop tasks if they hit limits. The tuning config for the applicable tasks adds two new configurations. * `maxSegmentIntervalsPermitted`: The number of segment intervals that a single job can identify for ingest dynamically * `maxAggregateSegmentIntervalShardsPermitted`: The aggregate number of shards across all intervals a job can create if sharding is discovered dynamically before ingestion. It is important to note that these limits are only applied when the information is obtained at runtime by the indexing job. For the segment intervals, we only ever enforce the limit if the spec has `null` intervals. For the aggregate sharding, we only ever enforce the limit if we run a determine partitions phase where we scan the data to determine bucket counts for each interval. Therefore, it is assumed that if the user is supplying the information up front for intervals and sharding, they are well aware of the scope of their ingest and we should not interfere with that. <!-- In each section, please describe design decisions made, including: - Choice of algorithms - Behavioral aspects. What configuration values are acceptable? 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If something hasn't changed since the original discussion, you can omit a detailed discussion of those aspects of the design here, perhaps apart from brief mentioning for the sake of readability of this PR description. --> <!-- Some of the aspects mentioned above may be omitted for simple and small changes. --> <hr> This PR has: - [ ] been self-reviewed. - [ ] added documentation for new or modified features or behaviors. - [ ] added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader. - [ ] added unit tests or modified existing tests to cover new code paths, ensuring the threshold for [code coverage](https://github.com/apache/druid/blob/master/dev/code-review/code-coverage.md) is met. - [ ] added integration tests. - [ ] been tested in a test Druid cluster. <!-- Check the items by putting "x" in the brackets for the done things. Not all of these items apply to every PR. Remove the items which are not done or not relevant to the PR. None of the items from the checklist above are strictly necessary, but it would be very helpful if you at least self-review the PR. --> <hr> ##### Key changed/added classes in this PR * HadoopTuningConfig * HadoopIndexTask * IndexTask * TuningConfig ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
