Shard level indexing pressure improves the current Indexing Pressure framework which performs memory accounting at node level and rejects the requests. This takes a step further to have rejections based on the memory accounting at shard level along with other key performance factors like throughput and last successful requests.
**Key features**
- Granular tracking of indexing tasks performance, at every shard level, for each node role i.e. coordinator, primary and replica.
- Smarter rejections by discarding the requests intended only for problematic index or shard, while still allowing others to continue (fairness in rejection).
- Rejections thresholds governed by combination of configurable parameters (such as memory limits on node) and dynamic parameters (such as latency increase, throughput degradation).
- Node level and shard level indexing pressure statistics exposed through stats api.
- Integration of Indexing pressure stats with Plugins for for metric visibility and auto-tuning in future.
- Control knobs to tune to the key performance thresholds which control rejections, to address any specific requirement or issues.
- Control knobs to run the feature in shadow-mode or enforced-mode. In shadow-mode only internal rejection breakdown metrics will be published while no actual rejections will be performed.
The changes were divided into small manageable chunks as part of the following PRs against a feature branch.
- Add Shard Indexing Pressure Settings. #716
- Add Shard Indexing Pressure Tracker. #717
- Refactor IndexingPressure to allow extension. #718
- Add Shard Indexing Pressure Store #838
- Add Shard Indexing Pressure Memory Manager #945
- Add ShardIndexingPressure framework level construct and Stats #1015
- Add Indexing Pressure Service which acts as orchestrator for IP #1084
- Add plumbing logic for IndexingPressureService in Transport Actions. #1113
- Add shard indexing pressure metric/stats via rest end point. #1171
- Add shard indexing pressure integration tests. #1198
Signed-off-by: Saurabh Singh <sisurab@amazon.com>
Co-authored-by: Saurabh Singh <sisurab@amazon.com>
Co-authored-by: Rabi Panda <adnapibar@gmail.com>
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