Reconfigure connection settings

MySQL  |  PostgreSQL  |  SQL Server

Preview

This feature is subject to the "Pre-GA Offerings Terms" in the General Service Terms section of theService Specific Terms. You can process personal data for this feature as outlined in theCloud Data Processing Addendum, subject to the obligations and restrictions described in the agreement under which you access Google Cloud. Pre-GA features are available "as is" and might have limited support. For more information, see thelaunch stage descriptions.

This page describes how to manage databases with a high number of simultaneousclient connections and a high number of database connection threads. Thisrecommender is calledReconfigure connection settings.

Every day, this recommender analyzes metrics for the following:

  • The peak number of database connections by tracking the value ofthemax_used_connections flag. If the maximum number of connections sincethe server restarted is 80% of the valuemax_connections,Reconfigureconnection settings recommends that you increase the value ofmax_connections .

    For more information on increasing the value ofmax_connections, seeMaximum concurrent connections.

  • The number of new database connection threads compared to the number ofexisting database connection threads. If more than 50% of connections resultin new threads instead of reusing cached ones, or if the value ofthread_cache_size is set to 0, thenReconfigure connection settingsrecommends that you increase the value ofthread_cache_size.

    For more information on increasing the value ofmax_connections, seeOptimize high CPU utilization in instances.This feature is inPreview.

Pricing

TheReconfigure connection settings recommender is in theStandardRecommender pricing tier.

Before you begin

Enable the Recommender API.

Required roles and permissions

To get the permissions to view and work with insights and recommendations, ensure that you have the requiredIdentity and Access Management (IAM) roles.

TaskRole
View recommendationsrecommender.cloudsqlViewer orcloudsql.admin.
Apply recommendationscloudsql.editor orcloudsql.admin.
For more information about IAM roles, seeIAM basic and predefined roles reference andManage access to projects, folders, and organizations.

List the recommendations

To list the recommendations, follow these steps:

Console

To list recommendations about instance performance, follow these steps:

  1. Go to theCloud SQL Instances page.

Go to Cloud SQL Instances

  1. On theImprove instance health by investigating issues and acting onrecommendations banner, clickExpand Details.

Alternatively, follow these steps:

  1. Go to theActive Assist. See alsoFind and apply recommendations with the Recommendations.

    Go to the Active Assist

  2. In theAll recommendations card, clickPerformance .

gcloud

Run thegcloud recommender recommendations list command as follows:

gcloud recommender recommendations list \--project=PROJECT_ID \--location=LOCATION \--recommender=google.cloudsql.instance.PerformanceRecommender \--filter=recommenderSubtype=MYSQL_RECONFIG_CONNECTIONS

Replace the following:

  • PROJECT_ID: your project ID
  • LOCATION: a region where your instances are located, such asus-central1

API

Call therecommendations.list method as follows:

GET https://recommender.googleapis.com/v1/projects/PROJECT_ID/locations/LOCATION/recommenders/google.cloudsql.instance.PerformanceRecommender/recommendations

Replace the following:

  • PROJECT_ID: your project ID
  • LOCATION: a region where your instances are located, such asus-central1

View insights and detailed recommendations

To view insights and detailed recommendations, follow these steps:

Console

Do one of the following:

  • On thePerformance Recommendations page, click thePerformancerecommendations card and then clickReconfigure connection settings.The recommendation panel appears, which contains insights and detailedrecommendations for the instance.

  • On theInstances page, clickReconfigure connection settings.The list of instances displays only those instances for which therecommendation applies.

gcloud

Run thegcloud recommender insights list command as follows:

gcloud recommender insights list \--project=PROJECT_ID \--location=LOCATION \--insight-type=google.cloudsql.instance.PerformanceInsight \--filter=insightSubtype=INSIGHT_SUBTYPE

Replace the following:

  • PROJECT_ID: your project ID
  • LOCATION: a region where your instances are located, such asus-central1
  • INSIGHT_SUBTYPE: set this parameter to one of the following:
    • MYSQL_HIGH_NUMER_OF_CONNECTIONS: display insights forthe number of database connections for your instance
    • MYSQL_HIGH_THREAD_CACHE_MISS_RATE: display insights forthe number of new database connection threads without using thethread cache for your instance

API

Call theinsights.list method as follows:

GET https://recommender.googleapis.com/v1/projects/PROJECT_ID/locations/LOCATION/insightTypes/google.cloudsql.instance.PerformanceInsight/insights

Replace the following:

  • PROJECT_ID: your project ID
  • LOCATION: a region where your instances are located, such asus-central1

Apply the recommendation

To implement this recommendation, do one of the following:

  • To apply the recommendation for the connection thread cache size, do one ofthe following:

    • If the value ofthread_cache_size is set to 0, then enable the threadcache by setting this flag to a value greater than 0.

    • If the value ofthread_cache_size is greater than 0, then increase thevalue of this flag.thread_cache_size should be equivalent to the averagenumber of connections to the database. Increase the value ofthread_cache_size if the number of new threads is higher than the currentsetting.

  • To apply the database connection recommendation, increase the value of themax_connections flag. The recommendation is updated daily, so after youincrease the value of this flag, wait for 24 hours before checking the recommendation again. For more information onincreasing the value ofmax_connections, seeMaximum concurrent connections.

Note: Increasingthread_cache_size andmax_connections requires more memory.After increasing these flags, monitor the memory usage.

What's next

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Last updated 2025-12-15 UTC.