View performance capture logs

Performance capture collects and sends instance metrics data to Cloud Logging in the mysql-performance-capture.log file.

For more information about viewing logs in Cloud Logging, see View logs by using the Logs Explorer.

Before you begin

To view performance capture logs, you must have the proper permissions to view logs in Cloud Logging for your project and instance.

Required roles and permissions

To get the permissions that you need to view performance capture logs, ask your administrator to grant you the Logs Viewer (roles/logging.viewer) IAM role on the project of the instance. For more information about granting roles, see Manage access to projects, folders, and organizations.

You might also be able to get the required permissions through custom roles or other predefined roles.

View performance capture logs

To view performance capture logs, do the following:

  1. In the Google Cloud console, go to the Cloud Logging page.

    Go to Cloud Logging

  2. Click All resources, then select Cloud SQL Database.
  3. Select your Cloud SQL instance.

  4. Filter for the log name:

    logName="projects/PROJECT_ID/logs/cloudsql.googleapis.com%2Fmysql-performance-capture.log"

    Replace PROJECT_ID with your project ID.

    The log payload is in the string format and contains the output of captured commands like SHOW ENGINE INNODB STATUS spanning across multiple log lines.

Review the data in a performance capture log

Each performance capture log is triggered by a performance event that you defined for your instance. The following table correlates performance capture log entries with the configuring thresholds and provides a description of the performance data report that you can view in the entry log.

Performance capture log entry Description Threshold trigger Report name
Active queries Captures database load metrics including connection and transaction counts grouped by state, active query counts bucketed by runtime duration (<2 seconds, 2 to 10 seconds, ≥10 seconds), and detailed information for the top 50 longest-running transactions or queries. This report helps identify periods of high load and pinpoint specific slow queries.

For more information about how to interpret data about InnoDB transactions and processes, see The INFORMATION_SCHEMA INNODB_TRX Table and The processlist Table in the MySQL documentation.
  • runningThreadsThreshold (Cloud SQL Admin API)
  • running-threads-threshold (gcloud CLI)
 activequeries
InnoDB status Provides information about the state of the InnoDB storage engine at the time of the performance event. This is critical for diagnosing lock contention, transaction issues, buffer pool problems, and History List Length growth. Keywords to look for:
  • TRANSACTIONS (long-running transactions, lock waits)
  • SEMAPHORES (mutex contention)
  • LATEST DETECTED DEADLOCK
  • BUFFER POOL AND MEMORY
  • HISTORY LIST LENGTH
For more information about InnoDB standard monitor output, see InnoDB Standard Monitor and Lock Monitor Output in the MySQL documentation.
  • runningThreadsThreshold (Cloud SQL Admin API)
  • running-threads-threshold (gcloud CLI)
 innodbstatus
Replication analysis Contains replication diagnostic information, including the output of SHOW REPLICA STATUS, GTID sets, and details from performance schema tools. The report also includes the first five events from the relay log following the execution position at the time of the performance event. This report can be used to diagnose replication errors or delays.

For more information about SHOW REPLICA STATUS output and replica applier threads, see SHOW REPLICA STATUS Statement and Monitoring Replication Applier Worker Threads in the MySQL documentation.
  • secondsBehindSourceThreshold (Cloud SQL Admin API)
  • seconds-behind-source-threshold (gcloud CLI)
 replicastatus
Transaction watcher data Details on the long-running transactions being tracked.

For more information about how to interpret data about InnoDB transactions, see The INFORMATION_SCHEMA INNODB_TRX Table in the MySQL documentation.
  • transactionDurationThreshold (Cloud SQL Admin API)
  • transaction-duration-threshold (gcloud CLI)
 LongRunningTransactions

Filter the data in a performance capture log

When performance capture detects an issue based on a threshold configured for your Cloud SQL instance, the monitoring agent sends labeled log entries associated with the instance and type of report to Cloud Logging.

To help you sort through logs and correlate log entries with the performance issues observed for your instance, you can filter the performance capture log entries by label.

Each log entry is labeled with the following two labels:

  • Time of the event, or labels.EVENT_TIME: indicates the time of the performance capture entry log. The format is a unique timestamp string YYYY-MM-DDTHH:MM:SSZ. For example, 2025-10-16T13:12:07Z.

  • Filename, or labels.FILE_NAME: identifies the type of report and the sequence number of the performance capture log entry triggered by a performance event. The format is INSTANCE_TYPE_SEQUENCE_NUMBER_REPORT_TYPE. For example, primary_1_activequeries, which is the first performance capture log entry of an active queries report.

Example filters

This section provides examples of how to filter the mysql-performance-capture.log file for specific log entries for analysis.

In the following examples, replace the following:

  • PROJECT_ID: project ID of the Cloud SQL instance
  • TIMESTAMP: timestamp of the triggering performance event in the format YYYY-MM-DDTHH:MM:SSZ. For example, 2025-10-16T13:12:07Z

Filter by a specific performance event

To filter by a specific performance event, use the labels.EVENT_TIME label to find related log entries.

For example, to get reports for a specific performance event, use the following queries in Logging Logs Explorer query builder.

Get all reports for a specific event

logName="projects/PROJECT_ID/logs/cloudsql.googleapis.com%2Fmysql-performance-capture.log"
labels.EVENT_TIME="TIMESTAMP"

Get InnoDB report for a specific event

logName="projects/PROJECT_ID/logs/cloudsql.googleapis.com%2Fmysql-performance-capture.log"
labels.EVENT_TIME="TIMESTAMP"
labels.FILE_NAME=~"innodbstatus"

Get only the first log entry for all report types for a specific event

logName="projects/PROJECT_ID/logs/cloudsql.googleapis.com%2Fmysql-performance-capture.log"
labels.EVENT_TIME="TIMESTAMP"
labels.FILE_NAME=~"_1_"

Filter across filenames

Get all activequeries reports across all events

This general query is useful for seeing how active queries look during any performance event.

logName="projects/PROJECT_ID/logs/cloudsql.googleapis.com%2Fmysql-performance-capture.log"
labels.FILE_NAME=~"activequeries"

Replace the following:

  • PROJECT_ID: project ID of the Cloud SQL instance

Compare the 1st and 3rd innodbstatus reports for a specific event

logName="projects/PROJECT_ID/logs/cloudsql.googleapis.com%2Fmysql-performance-capture.log"
labels.EVENT_TIME="TIMESTAMP"
(labels.FILE_NAME="primary_1_innodbstatus" OR labels.FILE_NAME="primary_3_innodbstatus")

Replace the following:

  • PROJECT_ID: project ID of the Cloud SQL instance
  • TIMESTAMP: timestamp of the triggering performance event in the format YYYY-MM-DDTHH:MM:SSZ. For example, 2025-10-16T13:12:07Z

Find the first activequeries report for any event that occurred after a certain time

logName="projects/PROJECT_ID/logs/cloudsql.googleapis.com%2Fmysql-performance-capture.log"
labels.FILE_NAME="primary_1_activequeries"
timestamp > "TIMESTAMP"

Replace the following:

  • PROJECT_ID: project ID of the Cloud SQL instance
  • TIMESTAMP: timestamp in the format YYYY-MM-DDTHH:MM:SSZ. For example, 2025-10-16T13:12:07Z

Search for specific text within any InnoDB status report

logName="projects/PROJECT_ID/logs/cloudsql.googleapis.com%2Fmysql-performance-capture.log"
labels.FILE_NAME=~"innodbstatus"
textPayload:"SEARCH_TEXT"

Replace the following:

  • PROJECT_ID: project ID of the Cloud SQL instance
  • SEARCH_TEXT: the text that you want to search for. For example, SEMAPHORE WAITS