pgbench: Add latency percentile reporting with histogram-based tracking #831
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Add --percentile[=LIST] option to report latency percentiles during pgbench runs. By default reports p50, p90, p99, p99.9, and p99.99. Users can specify a custom comma-separated list of percentiles (0-100) to report. Implementation details: - Multi-tier histogram with bounded memory (~100KB per histogram): * Fine buckets: 0-100ms at 100μs resolution (1000 buckets) * Coarse buckets: 100ms-10s at 1ms resolution (9900 buckets) * Medium buckets: 10s-120s at 100ms resolution (1100 buckets) * Large buckets: 120s-1200s at 1s resolution (1080 buckets) - Dynamic overflow tracking for latencies exceeding 20 minutes, storing individual values in a growable array for accurate tail percentiles - Per-command percentile reporting when combined with -r flag, with percentiles displayed on a single line per command - Per-script percentile aggregation across all threads New options: - --percentile[=LIST]: Enable percentile reporting with optional custom list - --debug-latency-multiplier=N: Multiply latencies for testing overflow handling Memory considerations documented for high-concurrency scenarios with per-command reporting enabled. Includes comprehensive TAP test coverage for custom percentile lists, overflow handling, and per-command reporting.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Add --percentile[=LIST] option to report latency percentiles during pgbench runs. By default reports p50, p90, p99, p99.9, and p99.99. Users can specify a custom comma-separated list of percentiles (0-100) to report.
Implementation details:
New options:
Memory considerations documented for high-concurrency scenarios with per-command reporting enabled. Includes comprehensive TAP test coverage for custom percentile lists, overflow handling, and per-command reporting.