Manage open tables and open table definitions

MySQL   |  PostgreSQL   |  SQL Server

Preview — Gemini in Databases

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This page describes how to manage instances with a high number of open tables and a high number of open table definitions. This recommender is called Manage open tables.

Every day, this recommender analyzes metrics for the following:

• The number of open tables or open table definitions for an instance as follows:
  • If the number of open tables or open table definitions increases by 1 table every 2 seconds, or faster, during the previous 24 hours.
  • If the number of open tables or open table definitions is equal to or more than the value of table_open_cache and table_definition_cache, respectively. If either of these are true, then the recommender advises you to increase the value of table_open_cache or table_definition_cache.

For more information on increasing the value of table_open_cache and table_definition_cache, see Table limit.

Important: This recommender is only available if you have enabled Gemini in Databases. For more information on enabling Gemini in Databases, see Set up Database Center.

Pricing

The Manage open tables recommender is in the Standard Recommender 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 required Identity and Access Management (IAM) roles.

Task	Role
View recommendations	recommender.cloudsqlViewer or cloudsql.admin
Apply recommendations	cloudsql.editor or cloudsql.admin

For more information about IAM roles, see IAM basic and predefined roles reference and Manage 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 the Cloud SQL Instances page.

Go to Cloud SQL Instances

1. On the Improve instance health by investigating issues and acting on recommendations banner, click Expand Details .

Alternatively, follow these steps:

1. Go to the Recommendation Hub. See also Find and apply recommendations with the Recommendations.

   Go to the Recommendation Hub

2. In the All recommendations card, click Performance .

gcloud

Run the gcloud recommender recommendations list command as follows:

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

Replace the following:

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

API

Call the recommendations.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 as us-central1

View insights and detailed recommendations

To view insights and detailed recommendations, follow these steps:

Console

Do one of the following:

• On the Performance Recommendations page, click the Performance recommendations card and then click Manage open tables. The recommendation panel appears, which contains insights and detailed recommendations for the instance.

• On the Instances page, click Manage open tables. The list of instances displays only those instances for which the recommendation applies.

gcloud

Run the gcloud 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 as us-central1
• INSIGHT_SUBTYPE: set this parameter to one of the following:
  • MYSQL_HIGH_NUMBER_OF_OPEN_TABLES: display insights for the number of open tables for your instance
  • MYSQL_HIGH_NUMBER_OF_OPEN_TABLE_DEFINITIONS: display insights for the number of open table definitions for your instance

API

Call the insights.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 as us-central1

Apply the recommendation

To implement this recommendation, do one of the following:

• For a high number of open tables, increase the value of table_open_cache by 500 until the recommendation disappears.

• For a high number of open table definitions, increase the value of table_definition_cache by 500 until the recommendation disappears.

Note: Increasing table_open_cache ortable_definition_cache requires more memory. After increasing these flags, monitor the memory usage .

This recommendation is updated daily, so after you increase the value of either table_open_cache or table_definition_cache, wait for 24 hours before checking the recommendation again. For more information on increasing the value of table_open_cache and table_definition_cache, see Table limit.

What's next

• Google Cloud recommenders