Troubleshooting Cloud SQL for MySQL

Topics in this page include:

Backup and recovery

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For this problem... The issue might be... Try this...
Can't see current operation status. The user interface only shows success or failure. Use these database commands to find out more.
Can't find the operation originator. The user interface doesn't show who started an operation. Use audit logging to find out.
Out of disk space during automated backup. Instance reached hard disk space limits. Check the file system size and quota.
Can't do backup after instance deleted. Instance was deleted. Recreate from an export, or contact customer support if within the grace period.
Automated backup seems stuck. Backup time is correlated with database size. Contact customer support if you really need to cancel the operation.
Restore fails. Dump file may contain database users who do not yet exist. Create the database users before restoring.
Operation isn't valid for this instance. Destination instance size is smaller than the source. Increase the destination instance size.
Increase number of days to keep automated backups. Only seven automated backups are retained. Manage your own manual backups.
Unknown error in backup failure. Backup might have timed out. Check these flags.

Can't see current operation status

You can't see the status of an operation in the Google Cloud Console.

The issue might be

The Google Cloud Console reports only success or failure when done, and is not designed to return warnings.

Things to try

Connect to the database and run SHOW WARNINGS.


Can't find the operation originator

You want to find out who issued an on-demand backup operation.

The issue might be

The instance operations page in the Google Cloud Console does not show who initiated an operation.

Things to try

Look in the logs and filter by text to find the user. You may need to use audit logs for private information. Relevant log files include:

  • cloudsql.googlapis.com/mysql-general.log
  • cloudsql.googleapis.com/mysql.err
  • cloudaudit.googleapis.com/activity may also be available, if Cloud Audit Logs is enabled.


Out of disk space during automated backup

You see the error message [ERROR] InnoDB: Write to file ./ibtmp1 failed at offset XXXX, YYYY bytes should have been written, only 0 were written.

The issue might be

The instance reached a hard limit during an automated backup. Temporary files can expand beyond available disk space during a backup.

Things to try

Check that the disk is not full or out of disk quota. You can either manually increase the disk size or enable auto storage increase.


Can't do backup after instance deleted

You can't do a backup after deleting the instance.

The issue might be

Instance was deleted.

Things to try

  • The grace period for a Cloud SQL instance purge is four days. During this time, customer support can recreate the instance. After instances are purged, no data recovery is possible.
  • If you have done an export, you can create a new instance and then do an import to recreate the database. Exports are written to Cloud Storage and imports are read from there.

Automated backup is stuck

Automated backup is stuck for many hours and can't be canceled.

The issue might be

Backups can take a long time depending on the database size.

Things to try

If you really need to cancel the operation, you can ask customer support to force restart the instance.


Restore from backup fails

A restore operation can fail when one or more users referenced in the SQL dump file do not exist.

The issue might be

Before restoring a SQL dump, all the database users who own objects or were granted permissions on objects in the dumped database must exist. If they do not, the restore fails to recreate the objects with the original ownership and/or permissions.

Things to try

Create the database users before restoring from the SQL dump.


Operation isn't valid for this instance

You see the error message HTTP Error 400: This operation isn't valid for this instance from an API call to instances.restoreBackup.

The issue might be

You cannot restore from a backup of an instance with a storage size (XX GB) that is smaller than the backup size (YY GB).

Things to try

Edit the target instance to increase its storage size.


Increase number of days to keep automated backups

You want to increase the number of days that you can keep automatic backups from seven to 30 days, or longer.

The issue might be

Only seven backups are retained. Backups get pruned regularly due to the cost and size of retaining backups. Unfortunately, this means that the currently visible backups are the only automated backups you can restore from.

Things to try

To keep backups indefinitely, you can create an on-demand backup yourself, as they are not deleted in the same way as automated backups. On-demand backups remain indefinitely. That is, they remain until they are deleted or the instance they belong to gets deleted. Since that type of backup is not deleted automatically, it can affect billing.


Unknown error in backup failure

Backup failed and you see Unknown error.

The issue might be

The backup creation reaching the ten minute timeout. There is a ten minute timeout set on the automated backup, and the backup is supposed to finish in that time.

Things to try

There are two flags that influence the backup creation: checkpoint_timeout and checkpoint_completion_target. At the start of the backup a slow checkpoint is run and it takes checkpoint_completion_target multiplied by checkpoint_timeout.

For example, 900 sec * 0.9 sec = 810 sec = 13.5 min. For this reason a timeout occurs. Decreasing the value of the checkpoint_completion_target should fix the issue in this case.

Cloning

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For this problem... The issue might be... Try this...
Cloning fails with constraints/sql.restrictAuthorizedNetworks error. Blocked by Authorized Networks configuration. Try one of these options.

Cloning fails with a constraints/sql.restrictAuthorizedNetworks error

Cloning fails with a constraints/sql.restrictAuthorizedNetworks error.

The issue might be

The cloning operation is blocked by the Authorized Networks configuration. Authorized Networks are configured for public IP addresses in the Connectivity section of the Google Cloud Console, and cloning is not permitted due to security considerations.

Things to try

Remove all Authorized Networks entries from the Cloud SQL instance if you can. Otherwise, create a replica without any Authorized Networks entries.

Connectivity

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For this problem... The issue might be... Try this...
Aborted connection. Error reading packets or connection aborted. See these things to try.
Unauthorized to connect errors. There can be many root causes. See these things to try.
Network association failed. Service Networking API is not enabled in the project. Enable the Service Networking API in the project.
Remaining connection slots are reserved. The maximum number of connections has been reached. Increase the max_connections flag.

Aborted connection

You see the error message Got an error reading communication packets , or Aborted connection xxx to db: DB_NAME.

The issue might be

  • Networking instability.
  • No response to TCP keep-alive commands (either the client or the server is not responsive, possibly overloaded).
  • The database engine connection lifetime was exceeded and the server terminated the connection.

Things to try

Applications should tolerate network failures and follow best practices such as connection pooling and retrying. Most connection poolers catch these errors where possible. Otherwise the application should either retry or fail gracefully.

For connection retry, we recommend the following methods:

  1. Exponential backoff. Increase the time interval between each retry, exponentially.
  2. Add randomized backoff also.
Combining these methods helps reduce throttling.


Unauthorized to connect

You see the error message Unauthorized to connect.

The issue might be

There can be many causes, as authorization occurs at many levels.

  • At the database level, the database user must exist and its password must match.
  • At the project level, the user may lack the correct IAM permissions.
  • At the Cloud SQL level, the root cause can depend on how you connect to your instance. If you are connecting directly to an instance through the public IP, the connection's source IP must be in the authorized network of the instance.

    Private IP connectivity is allowed by default, except when you are connecting from a non-RFC 1918 address. Non-RFC 1918 client addresses must be configured as authorized networks.

    Cloud SQL doesn't learn Non-RFC 1918 subnet routes from your VPC by default. You need to update the network peering to Cloud SQL to export any Non-RFC 1918 routes. For example:

    gcloud compute networks peerings update cloudsql-[mysql/postgres]-googleapis-com --network=NETWORK --export-subnet-routes-with-public-ip --project=PROJECT
    

    If you are connecting through the Cloud SQL Proxy, ensure that the IAM permissions are set up correctly.

  • At the network level, if the Cloud SQL instance is using public IP, the connection's source IP must be in an authorized network.

Things to try

  • Check the username and password.
  • Check the user's IAM roles and permissions.
  • If using public IP, make sure the source is in the authorized networks.

Network association failed

You see the error message Error: Network association failed due to the following error: set Service Networking service account as servicenetworking.serviceAgent role on consumer project.

The issue might be

The Service Networking API is not enabled in the project.

Things to try

Enable the Service Networking API in your project. If you see this error when you are trying to assign a private IP address to a Cloud SQL instance, and you are using a shared VPC, you also need to enable the Service Networking API for the host project.


Remaining connection slots are reserved

You see the error message FATAL: remaining connection slots are reserved for non-replication superuser connections.

The issue might be

The maximum number of connections has been reached.

Things to try

Edit the max_connections flag value. Increasing max_connections above a certain value can result in losing SLA support.

Creating instances

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For this problem... The issue might be... Try this...
Internal error. Missing service networking service account. Disable and re-enable the Service Networking API.
Terraform instance creation fails. Terraform configuration error. Inspect and repair the Terraform configuration file.
HTTP Error 409 in Terraform script. Another operation is already in progress. Fix the Terraform script to wait for each operation to finish.
Unknown error Trying to create an instance with the same name as one recently deleted. Or trying to create multiple instances simultaneously with a new private IP range being used. Use a different name for the instance or wait until it's been a week since the instance was deleted. Recreate failed instances consecutively using different names.

Internal error

You see the error message {"ResourceType":"sqladmin.v1beta4.instance", "ResourceErrorCode":"INTERNAL_ERROR","ResourceErrorMessage":null}.

The issue might be

The service project is likely missing the service networking service account required for this feature.

Things to try

To repair service permissions, disable the Service Networking API , wait five minutes and then re-enabled it.


Terraform instance creation fails

Terraform instance creation fails.

The issue might be

This is usually an issue within the Terraform script itself.

Things to try

Inspect and repair the Terraform configuration file.


409 error in Terraform script

You see the error message HTTP Error 409 in Terraform scripts.

The issue might be

Operation failed because another operation was already in progress

Things to try

Revise the script to halt execution until each instance operation is completed. Have the script poll and wait until a 200 is returned for the previous operation ID before continuing to the next step.


Unknown error

When trying to create an instance, you see an error message like Cloud SQL creation failed, error UNKNOWN.

The issue might be

Most likely you are trying to re-use the name of an instance you recently deleted. Instance names cannot be re-used for one week after deletion. Or you are trying to create multiple instances simultaneously using a new private IP range when only the first instance is created and others fail with Unknown error.

Things to try

Either use a different name for the instance, or wait one week to create a new one using that name. Create multiple instances consecutively instead of simultaneously.

Flags

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For this problem... The issue might be... Try this...
Data with character set utf8mb4. This character set is not supported. Filter utf8mb4 strings out of your data.
Enabling a flag crashes the instance. The max_connections flag value may be set too high. Contact customer support to request a flag removal.
Can't add the performance_schema flag. Instance size is too small. Update to a larger instance.
Time zone doesn't automatically change. Automated time zone change is not supported. Time must be changed manually. Learn more.

Data with character set utf8mb4

Failed to import data with character set utf8mb4.

The issue might be

The character set utf8mb4 is not supported even though the documentation has previously indicated it is.

Things to try

Filter utf8mb4 strings out of your data.


Enabling a flag crashes the instance

After enabling a flag the instances loop between panicking and crashing.

The issue might be

Setting the max_connections flag value too high causes this error.

Things to try

Contact customer support to request a flag removal followed by a hard drain. This forces the instance to restart on a different host with a fresh configuration without the undesired flag or setting.


Can't add the performance_schema flag

You cannot add the performance_schema flag because it isn't in the dropdown menu of supported flags.

The issue might be

The performance_schema and its variants (performance_schema_accounts_size, performance_schema_accounts_size, etc.) cannot be enabled on instances smaller than db-n1-standard-8 or db-n1-highmem-4.

Things to try

Edit the instance to upgrade to a larger size if you need to use this flag.


Time zone doesn't automatically change

The time zone didn't automatically change for daylight savings time.

The issue might be

Automated time zone changes are not supported in Cloud SQL and must be done manually, and not by string but by time zone offset value.

Things to try

Edit the instance to change the default_time_zone flag. Named areas are not supported. For example: Europe/LondonLondon is in the UTC time zone, which would be a supported value of +00:00 for the default_time_zone flag.

High availability

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For this problem... The issue might be... Try this...
Can't find metrics for manual failover. Only automatic failovers go into the metrics. N/A
CPU and RAM are near 100% usage Instance machine size is too small for the load. Upgrade the instance machine size.

Can't find metrics for manual failover

You performed a manual failover and can't find a corresponding entry in Metrics Explorer in the automatic failover metrics.

The issue might be

Only automatic failovers go into the metrics. Manually initiated failovers do not.

Things to try

N/A


CPU and RAM are near 100% usage

Cloud SQL instance resources (CPU and RAM) are near 100% usage, causing the high availability instance to go down.

The issue might be

The instance machine size is too small for the load.

Things to try

Edit the instance to upgrade to a larger machine size to get more CPUs and memory.

Import and export

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For this problem... The issue might be... Try this...
Can't see the operation status. The user interface only shows success or failure. Use these database commands to find out more.
408 Error (Timeout) during export. SQL export can take a long time depending on database size and export content. Use multiple CSV exports to reduce the size of each operation.
CSV export worked but SQL export failed. SQL export is more likely to encounter compatibility issues with Cloud SQL. Use CSV exports to export only what you need..
Export is taking too long. Cloud SQL does not support concurrent synchronous operations. Use export offloading. Learn more.
Error 1412: Table definition has changed. The table changed during export. Remove any table change statements from the dump operation.
Import fails. Exported file may contain database users who do not yet exist. Create the database users before doing the import.
Connection closed during the export operation. Query must produce data within first seven minutes. Test the query manually. Learn more.
Unknown error during export. Possible bandwidth issue. Ensure that both the instance and the Cloud Storage bucket are in the same region.
You want to automate exports. Cloud SQL does not provide a way to automate exports. Build your own pipeline to perform this functionality. Learn more.
ERROR_RDBMS: system error occurred. Cloud Storage permissions or non-existent table. Check permissions OR ensure table exists.
Error during import: table doesn't exist. A required table doesn't exist at the moment. Disable FOREIGN_KEY_CHECKS at beginning of import.

Can't see the operation status

You can't see the status of an ongoing operation.

The issue might be

The Google Cloud Console reports only success or failure when done, and is not designed to return warnings.

Things to try

Connect to the database and run SHOW WARNINGS.


408 Error (Timeout) during export

You see the error message 408 Error (Timeout) while performing an export job in Cloud SQL.

The issue might be

CSV and SQL formats do export differently. The SQL format exports the entire database, and likely takes longer to complete. The CSV format lets you define which elements of the database to include in the export,

Things to try

Use the CSV format, and run multiple, smaller export jobs to reduce the size and length of each operation.


CSV export worked but SQL export failed

CSV export worked but SQL export failed.

The issue might be

CSV and SQL formats do export differently. The SQL format exports the entire database, and likely takes longer to complete. The CSV format lets you define which elements of the database to include in the export,

Things to try

Use CSV exports to export only what you need.


Export is taking too long

Export is taking too long, blocking other operations.

The issue might be

Cloud SQL does not support concurrent synchronous operations.

Things to try

Try exporting smaller datasets at a time.


mysqldump: Error 1412: Table definition has changed

You see the error message mysqldump: Error 1412: Table definition has changed, retry transaction when dumping the table.

The issue might be

During the export process, there was a change in the table.

Things to try

The dump transaction can fail if you use the following statements during the export operation:

  • ALTER TABLE
  • CREATE TABLE
  • DROP TABLE
  • RENAME TABLE
  • TRUNCATE TABLE
Remove any of these statements from the dump operation.


Import fails

Import fails when one or more users referenced in the exported SQL dump file does not exist.

The issue might be

Before importing a SQL dump, all the database users who own objects or were granted permissions on objects in the dumped database must exist. If they do not, the restore fails to recreate the objects with the original ownership and/or permissions.

Things to try

Create the database users before importing the SQL dump.


Connection closed during the export operation

Connection closed during the export operation.

The issue might be

The connection to Cloud Storage may be timing out because the query running in the export is not producing any data within the first seven minutes since the export is initiated.

Things to try

Test the query manually by connecting from any client and sending the output of your query to STDOUT with the command below:

COPY (INSERT_YOUR_QUERY_HERE) TO STDOUT WITH ( FORMAT csv, DELIMITER ',', ENCODING 'UTF8', QUOTE '"', ESCAPE '"' ).

This is expected behavior since when the export is initiated, the client is expected to start sending data right away. Keeping the connection with no data sent ends up breaking the connection and eventually resulting in the export failing and leaving the operation in an uncertain state. Also, this is what the error message from gcloud is trying to say with this message:

operation is taking longer than expected.


Unknown error during export

You see the error message Unknown error while trying to export a database to a Cloud Storage bucket.

The issue might be

The transfer might be failing due to a bandwidth issue.

Things to try

The Cloud SQL instance may be located in a different region from the Cloud Storage bucket. Reading and writing data from one continent to another involves a lot of network usage, and can cause intermittent issues like this. Check the regions of your instance and bucket.


Want to automate exports

You want to automate exports.

The issue might be

Cloud SQL does not provide a way to automate exports.

Things to try

You can build your own automated export system using Google Cloud products: Cloud Scheduler, Pub/Sub, and Cloud Functions, as described here.


ERROR_RDBMS system error occurred

You see the error message [ERROR_RDBMS] system error occurred.

The issue might be

  • The user might not have all the Cloud Storage permissions it needs.
  • The database table might not exist.

Things to try

  1. Check that you have at least WRITER permissions on the bucket and READER permissions on the export file. For more information on configuring access control in Cloud Storage, see Create and Manage Access Control Lists.
  2. Ensure the table exists. If the table exists, confirm that you have the correct permissions on the bucket.

Error during import: table doesn't exist

An import operation fails with an error that a table doesn't exist.

The issue might be

Tables can have foreign key dependencies on other tables, and depending on the order of operations, one or more of those tables might not yet exist during the import operation.

Things to try

Add the following line at the start of the dump file:

  SET FOREIGN_KEY_CHECKS=0;

Additionally, add this line at the end of the dump file:

  SET FOREIGN_KEY_CHECKS=1;

These settings deactivate data integrity checks while the import operation is in progress, and reactivate them after the data is loaded. This doesn't affect the integrity of the data on the database, because the data was already validated during the creation of the dump file.

Logging

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For this problem... The issue might be... Try this...
Logging is using a lot of CPU and memory. Logging needs to be tuned. Try tuning logging resource usage.
Audit logs are not found. User authentication. Check user roles and permissions.
Operations information not found in logs. Audit logs are not enabled. Enable audit logging.
Logging is using a lot of disk space. Redo logs, binary logs, and general logs use disk space. Run these commands to get disk usage details.

Logging is using a lot of CPU and memory

Logging is using a lot of CPU and memory.

The issue might be

Logging usage needs to be tuned.

Things to try

The log_statement flag can be set to none and the logging_collector flag can be set to off. If logging is still occurring, there may be other log-related flags that can be tuned. You can edit the instance to modify these flags.


Audit logging

You turned on audit logging for Cloud SQL but are unable to find any audit logs in Cloud Logging

The issue might be

Data-Access logs are only written if the operation is an authenticated user-driven API call that creates, modifies, or reads user-created data, or if the operation accesses configuration files or metadata of resources.

Things to try

Check the roles and permissions of the user performing the operations.


Operation information not found in logs

You want to find more information about an operation. For example, a user was deleted but you can't find out who did it. The logs show the operation started but do not provide any more information.

The issue might be

You must enable audit logging for detailed and personal identifying information (PII) like this to be logged.

Things to try

Enable audit logging in your project.


Logging is using a lot of disk space

You want to find out how much disk space log files are using.

The issue might be

There are three kinds of log files that use disk space: redo logs, general logs and binary logs.

Things to try:

Run these commands for details on each type of log file:

SHOW VARIABLES LIKE 'innodb_log_file%';

SELECT ROUND(SUM(LENGTH(argument)/POW(1024,2),2) AS GB from mysql.general_log;

SHOW BINARY LOGS;

Managing instances

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For this problem... The issue might be... Try this...
Slow performance after restart. InnoDB cache is empty after restart, so all reads require a round trip to the backend to get data. Wait for all data to get caught up.
Slow crash recovery. A large general_log may have accumulated. Manage general logging. Learn more.
You want to find out what is using up storage. Most usage is either database tables, binary logs, or temporary files. See these tips on how to check.
Queries are blocked. One process is blocking everything else. Find and kill the blocking process. Learn more.
You are unable to manually delete binary logs. Binary logs cannot be manually deleted. Binary logs are automatically deleted with their associated automatic backup, which generally happens after about seven days.
You want to find information about temporary files. The temporary file name is ibtmp1. Try this database query to learn more.
You want to find out about table sizes. This information is available in the database. Try these database queries to learn more.
mysqld got a signal 11. Instance crashed because queries are creating too many connections. Refactor queries to avoid this.
Temporary storage increased automatic storage. Automatic storage is enabled. Restart deletes the temporary files but not reduce the storage. Only customer support can reset the instance size. Learn more.
Data is being automatically deleted. There is a script running somewhere doing this. Try to find the script.
The instance cannot be deleted. There can be more than one root cause. There can be more than one solution.
The instance is stuck due to large temporary data size. Too many temporary tables were created at one time. Restart the instance, and try this mitigation option.
Fatal error during upgrade. There could be many causes. Logs may reveal more. You may need to contact customer support to force a restart.
Instance is stuck on restart after running out of disk space. Automatic storage increase capability is not enabled. Enable automatic storage increase.
On-premises primary instance is stuck. N/A Cloud SQL customer support cannot help with instances that are not in Cloud SQL.
Slow shutdown on restart. Outstanding connections that don't terminate after 60 seconds can cause unclean shutdowns. Only have connections that last less than 60 seconds.
Access denied for user. User authentication, or possibly expired SSL/TLS certificates. Check user and cert statuses.
A user cannot be deleted. It could be that the user owns objects in the database. You may need to drop or reassign objects.
Cannot assign a private IP address to an existing instance in a Shared VPC. Instance addresses are tied to their projects upon creation. Create a new Cloud SQL instance to replace the existing one.
Particular queries are running slow. Database-specific issues or network latency. Check these suggestions.
Out of memory is indicated but monitoring charts don't show that. Some RAM may be in used by internal overhead processes. Ensure the instance has enough overhead for your workload.

Slow performance after restart

Slow performance after restart.

The issue might be

Cloud SQL allows caching of data in the InnoDB buffer pool. However, after a restart, this cache is always empty, and all reads require a round trip to the backend to get data. As a result, queries can be slower than expected until the cache is filled.

Things to try

N/A


Slow crash recovery

Slow crash recovery.

The issue might be

A large general_log may have accumulated.

Things to try

You can reduce crash recovery time by preventing a large general_log from accumulating. If you have general_log on, truncate the table and only enable general_log for short periods of time.

You can find out the size of the general logs by connecting to the database and running this query: SELECT ROUND(SUM(LENGTH(argument)/POW(1024,2)),2) from mysql.general_log;


Want to find out what is using up storage

You want to find out what is using up storage. For example, you notice that your database is using only three Gb, but storage says that 14 Gb is being used.

The issue might be

Most of the space not used by tables is used by binary logs and/or temporary files.

Things to try

  • You can check the storage occupied by binary logs using the following command in the MySQL command line interface: SHOW BINARY LOGS;
  • Temporary tables may also be occupying a significant amount of storage space. To check the temporary space usage, use the following command: SELECT * FROM INFORMATION_SCHEMA.FILES WHERE TABLESPACE_NAME='innodb_temporary'\G.
  • The following command lets you check the redo log size: SHOW VARIABLES LIKE 'innodb_log_file%';
  • You can check the size of general_log, if it is enabled, with the help of this command: SELECT ROUND(SUM(LENGTH(argument)/POW(1024,2),2) AS GB from mysql.general_log;

Queries are blocked

It is possible for queries to lock the MySQL database causing all subsequent queries to block/timeout.

The issue might be

One process is blocking all others.

Things to try

Connect to the database and execute this query: SHOW PROCESSLIST. The first item in the list may be the one holding the lock, which the subsequent items are waiting on.

The SHOW INNODB STATUS query can also be helpful.


Unable to manually delete binary logs

You find that you are unable to manually delete binary logs.

The issue might be

Binary logs cannot be manually deleted.

Things to try

Binary logs are automatically deleted with their associated automatic backup, which generally happens after about seven days.


Want to find information about temporary files

You want to find information about temporary files.

The issue might be

A file named ibtmp1 is used for storing temporary data. This file is reset upon database restart.

Things to try

To find information about temporary file usage, connect to the database and execute this query:

SELECT * FROM INFORMATION_SCHEMA.FILES WHERE TABLESPACE_NAME='innodb_temporary'\G


Want to find out about table sizes

You want to find out the sizes of the tables in your database.

The issue might be

This information is available in the database.

Things to try

Connect to the database and execute this query:

SELECT TABLE_SCHEMA, TABLE_NAME, sum(DATA_LENGTH+INDEX_LENGTH)/pow(1024,2) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA NOT IN ('PERFORMANCE_SCHEMA','INFORMATION_SCHEMA','SYS','MYSQL') GROUP BY TABLE_SCHEMA, TABLE_NAME;


mysqld got signal 11

The following error occurs:

mysqld got signal 11.

The issue might be

The instance probably crashed because queries are creating too many connections.

Things to try

Refactor the queries so that they don't create so many connections.


Temporary storage increased automatic storage

Temporary tables increased storage usage, and automatic storage was increased.

The issue might be

Automatic storage is enabled.

Things to try

Restarting to delete temporary tables does not reduce the automatically increased storage size.


Data is being automatically deleted

You notice that data is being automatically deleted at a regular interval.

The issue might be

Most likely a script is running somewhere in your environment.

Things to try

Look in the logs around the time of the deletion and see if there is a rogue script running from a dashboard or another automated process.


The instance cannot be deleted

You see the error message ERROR: (gcloud.sql.instances.delete) HTTP Error 409: The instance or operation is not in an appropriate state to handle the request, or the instance may have a INSTANCE_RISKY_FLAG_CONFIG flag status.

The issue might be

  1. Another operation is in progress.
  2. The INSTANCE_RISKY_FLAG_CONFIG warning is triggered whenever at least one beta flag is being used.

Things to try

  1. Cloud SQL operations do not run concurrently. Wait for the other operation to complete.
  2. Remove the risky flag settings and restart the instance.

The system is stuck due to large temporary data size

The system is stuck due to large temporary data size.

The issue might be

The system can create many temporary tables at one time, depending on the queries and the load.

Things to try

Unfortunately, you cannot shrink the ibtmp1 file by any method other than restarting the service.

One mitigation option is to create the temporary table with ROW_FORMAT=COMPRESSED, so it is stored in file-per-table tablespaces in the temporary file directory. However, the downside is performance costs associated with creating and removing a file-per-table tablespace for each temporary table.


Fatal error during upgrade

You see the error message ERROR_INTERNAL_FATAL when upgrading resources on instance.

The issue might be

There could be many causes.

Things to try

Logs may reveal more, but in any case customer support may be needed to force re-create the instance.


Instance is stuck on restart after running out of disk space

The instance is stuck on restart after running out of disk space

The issue might be

Automatic storage increase capability is not enabled.

Things to try

If your instance runs out of storage, and the automatic storage increase capability is not enabled, your instance goes offline. To avoid this issue, you can edit the instance to enable automatic storage increase.


on-premises primary instance is stuck

You want to know if Cloud SQL customer support can help when an on-premises primary instance is stuck.

The issue might be

The instance is not in Cloud SQL.

Things to try

Cloud SQL customer support cannot help with instances that are not in Cloud SQL.


Slow shutdown on restart

Slow shutdown on restart.

The issue might be

When an instance shuts down, any outstanding connections that don't terminate within 60 seconds makes the shutdown unclean.

Things to try

By only having connections that last less than 60 seconds, most unclean shutdowns can be avoided, including connections from the database command prompt. If you keep these connections open for hours or days, shutdowns can be unclean.


Access denied for user

You see the error message Access denied for user 'XXX'@'XXX' (using password: XXX).

The issue might be

There could be several root causes, including:

  • The username (or password) is incorrect.
  • The user is connecting from something other than @XXX.
  • The user doesn't have the correct privileges for the database to which they are trying to connect.

Things to try

  • Verify the username and corresponding password
  • Check the origin of the connection to see whether it matches where the user has been granted access privileges.
  • Check the user's grant privileges in the database,

Cannot delete user

You cannot delete a database user.

The issue might be

The user has objects in the database that depend on it. You first need to drop those objects or reassign them to another user.

Things to try

Find out which objects are dependent on the user, then drop or reassign those objects to a different user. This article discusses how to find the objects owned by the user.


Cannot assign a private IP address to an existing instance in a Shared VPC

You cannot assign a private IP address to an existing instance in a Shared VPC.

The issue might be

The reason behind that is because when a Cloud SQL instance is created it is automatically attached to a tenant project, and so will all the Cloud SQL instances in that same project. However, when the instance created is using private IP in a Shared VPC, it is attached to the tenant project associated with the Shared VPC host project.

Things to try

You can create a new Cloud SQL instance to replace the existing one.


Particular queries are running slow

CPU usage is consistently high.

The issue might be

Queries can be slow for many reasons, mostly due to specific database aspects. One reason that can involve Cloud SQL is network latency, when the source (writer or reader) resource and the destination (Cloud SQL) resource are in different regions.

Things to try

Refer to general performance tips, in particular:

For slow database inserts, updates, or deletes, consider the following actions:

  • Check the locations of the writer and database; sending data a long distance introduces latency.
  • Check the location of the reader and database; latency affects read performance even more than write performance
To reduce the latency the recommendation is to locate both the source and destination resources in the same region.


Out of memory is indicated but monitoring charts don't show that

An instance fails and report Out of memory but the Console or {monitoring_name} charts seem to show there is still memory remaining.

The issue might be

There are other factors beside your workload that can impact memory usage, such as the number of active connections and internal overhead processes. These are not always reflected in the monitoring charts.

Things to try

Ensure that the instance has enough overhead to account for your workload and some additional overhead.

Replication

Click the links in the table for details:

For this problem... The issue might be... Try this...
Read replica did not start replicating on creation. At least one backup must have been created after binary logging was enabled. Wait until at least one backup has been created after enabling binary logs.
Unable to create read replica - unknown error. There could be many root causes. Check the logs to find more information.
Disk is full. The primary instance disk size can become full during replica creation. Upgrade the primary instance to a larger disk size.
Replica instance is using too much memory. Replicas can cache often-requested read operations. Restart the replica instance to reclaim the temporary memory space.
Replication stopped. Max storage space was reached and automatic storage increase is not enabled. Enable automatic storage increase.
Replication lag is consistently high. There can be many different root causes. Increase the instance size of the replica or reduce the load on the database.

Read replica did not start replicating on creation

Read replica did not start replicating on creation.

The issue might be

The primary instance must have at least a week's worth of binlogs or else replicas cannot start replicating.

Things to try

Wait until there are enough binlogs.


Unable to create read replica - unknown error

Unable to create read replica - unknown error.

The issue might be

There is probably a more specific error in the log files.

Things to try

Inspect the logs in Cloud Logging to find the actual error. If the error is: set Service Networking service account as servicenetworking.serviceAgent role on consumer project, then disable and re-enable the Service Networking API. This action creates the service account necessary to continue with the process.


Disk is full

UPDATE_DISK_SIZE or mysqld: disk is full error.

The issue might be

The primary instance disk size can become full during replica creation.

Things to try

Edit the primary instance to upgrade it to a larger disk size.


Replica instance is using too much memory

The replica instance is using too much memory.

The issue might be

The replica uses temporary memory to cache often-requested read operations, which can lead it to use more memory than the primary instance.

Things to try

Restart the replica instance to reclaim the temporary memory space.


Replication stopped

Replication stopped.

The issue might be

The maximum storage limit was reached and >automatic storage increase is disabled.

Things to try

Edit the instance to enable automatic storage increase.


Replication lag is consistently high

Replication lag is consistently high.

The issue might be

The write load is too high for the replica to handle. Replication lag takes place when the SQL thread on a replica is unable to keep up with the IO thread. Some kinds of queries or workloads can cause temporary or permanent high replication lag for a given schema. Some of the typical causes of replication lag are:

  • Slow queries on the slave. These are discoverable by enabling log_slow_slave_statements and fixing them.
  • All tables should have unique/primary key. Every update on such a table without a unique/primary key causes full table scans on th replica.
  • Queries like DELETE ... WHERE field < 50000000 cause replication lag with row-based replication since a huge number of updates are piled up on the replica.

Things to try

Edit the instance to increase the size of the replica, or reduce the load on the database.