DOC-12277 Add contention examples using crdb_internal.transaction_contention_events #19377
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…tinuous monitoring.
…lyze using crdb_internal tables. In crdb-internal.md, moved the column table to include file transaction-contention-events-columns.md.
…lysis of support scenario.
…ng Insights page. In optimize-performance.json, added link to monitor-and-analyze-transaction-contention.html.
jonstjohn
approved these changes
Feb 25, 2025
src/current/_includes/v25.1/transaction-contention-events-columns.md
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suggestions from docs-reviewer-gpt: |
kevin-v-ngo
approved these changes
Apr 8, 2025
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| It is crucial to understand where [transaction contention]({% link {{ page.version.version }}/performance-best-practices-overview.md %}#transaction-contention) occurs and how it impacts your workload. Contention is a normal part of database operations. In many cases, it has limited impact on a workload. For example, a large number of contention events with a very short duration may not impact your workload. Similarly, a small number of contention events with longer duration may be acceptable if they occur outside the “user path”. However, if contention substantially contributes to query latency, it should be addressed. | ||
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| This page shows how to monitor and analyze two types of contention: [lock contention]({% link {{ page.version.version }}/performance-best-practices-overview.md %}#transaction-contention) and [serializable conflicts]({% link {{ page.version.version }}/performance-best-practices-overview.md %}#transaction-contention). These types of contention are exposed via different observability mechanisms: |
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Nit: These types of contention are exposed via different observability touchpoints.
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| The remaining sections address analyzing contention once identified: | ||
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| - [Analyze using `crdb_internal` tables](#analyze-using-crdb_internal-tables): A process to determine which workload and queries are involved in the contention. |
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Can we call out that not all crdb_internal are production ready and to refer to the doc here?
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| - [Failed Execution]({% link {{ page.version.version }}/ui-insights-page.md %}#slow-execution) | ||
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| A statement or transaction that failed due to a serialization error is identified as a Failed Execution. If the serialization error was due to contention, there is a conflicting or blocking transaction recorded. The execution details will show the conflicting transaction. |
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We capture all types of failures but for serialization errors, we capture more info (conflicting info) to help troubleshoot.
| `txn.restarts.writetooold` | Number of restarts due to a concurrent writer committing first | COUNTER | COUNT | ||
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| {{site.data.alerts.callout_info}} | ||
| Since these metrics are not categorized by database, interpreting them can be challenging. |
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Do we really need to call out it's challenging? Users can correlate these metrics with insights and SQL activity and find the 'database'
| Since these metrics are not categorized by database, interpreting them can be challenging. | ||
| {{site.data.alerts.end}} | ||
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| ## Monitor using `crdb_internal` tables |
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Can we call out that not all are production-ready
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Fixes DOC-12277
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