Due to an issue in MySQL, using generated columns might result in data
corruption. For more information, see
MySQL bug #82736.
Instance connection issues
Expired SSL/TLS certificates
If your instance is configured to use SSL, go to the
Cloud SQL Instances page
in the Google Cloud console and open the instance. Open its Connections page, select the
Security tab and make sure that your server certificate is valid. If it has expired, you must
add a new certificate and rotate to it.
Cloud SQL Auth Proxy version
If you are connecting using the Cloud SQL Auth Proxy, make sure you are using the
most recent version. For more information, see
Keeping the Cloud SQL Auth Proxy up to date.
Not authorized to connect
If you try to connect to an instance that does not exist in that project,
the error message only says that you are not authorized to access that
instance.
Can't create a Cloud SQL instance
If you see the Failed to create subnetwork. Router status is temporarily
unavailable. Please try again later. Help Token: [token-ID] error
message, try to create the Cloud SQL instance again.
Administrative issues
Only one long-running Cloud SQL import or export operation can run at a time on an instance. When you start an operation, make sure you don't need to perform other operations on the instance. Also, when you start the operation, you can cancel it.
MySQL auto-commits on each DDL statement. Cloud SQL
persists all steps of the import up to cancelling the
instance. Therefore, you might have to clean up the data on the
instance manually.
Issues with importing and exporting data
CSV export does not format NULLs and newlines correctly.
When you export data as CSV using the Cloud SQL export feature,
NULLs are exported as "N, which can cause the CSV file to contain
unbalanced quotation marks. Additionally, if your
text data contains a newline character, a trailing quote mark is added
at the end of the line.
When you import a file that you exported using the default escape character,
the file treats the value as "NULL" instead of NULL. To override the default
when you export the file, use --escape="5C".
The SQL Mode setting affects how Cloud SQL interprets SQL queries.
For example, if you export from a database without Strict SQL enabled, then
try to import to Cloud SQL (which enables Strict SQL by default), the
import might fail. The best practice is to use the same SQL Mode on import
that you used for export.
The DEFINER clause may cause import to fail
A DEFINER clause may cause an import operation to fail if the DEFINER user is
a SUPER or system user and is different from the user doing the import into
Cloud SQL. Learn more about DEFINER usage
and potential workarounds in Cloud SQL.
If you're trying to import and export data from a large database (for example,
a database that has 500 GB of data or greater), then the import and export
operations might take a long time to complete. In addition, other operations
(for example, the backup operation) aren't available for you to perform
while the import or export is occurring. A potential option to improve the
performance of the import and export process is to restore a previous backup using gcloud
or the API.
Cloud Storage supports a
maximum single-object size up five terabytes.
If you have databases larger than 5TB, the export operation to
Cloud Storage fails. In this case, you need to break down your
export files into smaller segments.
Transaction logs and disk growth
Logs are purged once daily, not continuously. When the number of days of log
retention is configured to be the same as the number of backups, a day of
logging might be lost, depending on when the backup occurs. For example, setting
log retention to seven days and backup retention to seven backups means that
between six and seven days of logs will be retained.
We recommend setting the number of backups to at least one more than the days of
log retention to guarantee a minimum of specified days of log retention.
Issues with upgrading your MySQL instance
If you use Database Migration Service to upgrade your MySQL instance from version 5.7 to version 8.0, and you have stored procedures created in the database named mysql in your version 5.7 instance, then your stored procedures may not get copied to the mysql database in the upgraded version 8.0 instance. Also, you may not be able to create stored procedures in the mysql database in the upgraded instance.
Issues with InnoDB page compression
InnoDB page compression
can improve the performance of update queries by reducing the amount of data that
needs to be read and written to disk. However, page compression can impact performance on the
update queries on frequently updated tables. To evaluate
the impact of page compression on your update queries, you can run a performance
test with and without page compression. This helps you to observe how page
compression affects the performance of your workload.
You can optimize page compression performance as follows:
Use a compression algorithm suitable for your data type. For example, use LZ4
for text data and ZLIB for binary data.
Avoid using compression for data that is frequently updated.
Compressing and decompressing data can slow down your update queries.
Issues related to Cloud Monitoring or Cloud Logging
Instances with the following region names are displayed incorrectly in certain
contexts, as follows:
us-central1 is displayed as us-central
europe-west1 is displayed as europe
asia-east1 is displayed as asia
This issue occurs in the following contexts:
Alerting in Cloud Monitoring
Metrics Explorer
Cloud Logging
You can mitigate the issue for Alerting in Cloud Monitoring, and for Metrics
Explorer, by using
Resource metadata labels.
Use the system metadata label region instead of the
cloudsql_database
monitored resource label region.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-28 UTC."],[],[],null,["# Known issues\n\n\u003cbr /\u003e\n\nMySQL \\| [PostgreSQL](/sql/docs/postgres/known-issues \"View this page for the PostgreSQL database engine\") \\| [SQL Server](/sql/docs/sqlserver/known-issues \"View this page for the SQL Server database engine\")\n\n\u003cbr /\u003e\n\n\u003cbr /\u003e\n\nThis page lists known issues with Cloud SQL for MySQL, along with\nways you can avoid or recover from these issues.\nIf you are experiencing issues with your instance, make sure you also review the [Operational Guidelines](/sql/docs/mysql/operational-guidelines), as well as the information in [Diagnosing Issues](/sql/docs/mysql/diagnose-issues).\n\n### Data durability and availability issues\n\n- Generated columns (MySQL 5.7 instances only)\n\n Due to an issue in MySQL, using generated columns might result in data\n corruption. For more information, see\n [MySQL bug #82736](https://bugs.mysql.com/bug.php?id=82736).\n\n### Instance connection issues\n\n- Expired SSL/TLS certificates\n\n\n If your instance is configured to use SSL, go to the\n [Cloud SQL Instances page](https://console.cloud.google.com/sql/instances)\n in the Google Cloud console and open the instance. Open its **Connections** page, select the\n **Security** tab and make sure that your server certificate is valid. If it has expired, you must\n add a new certificate and rotate to it.\n\n \u003cbr /\u003e\n\n- Cloud SQL Auth Proxy version\n\n If you are connecting using the Cloud SQL Auth Proxy, make sure you are using the\n most recent version. For more information, see\n [Keeping the Cloud SQL Auth Proxy up to date](/sql/docs/mysql/sql-proxy#keep-current).\n- Not authorized to connect\n\n If you try to connect to an instance that does not exist in that project,\n the error message only says that you are not authorized to access that\n instance.\n- Can't create a Cloud SQL instance\n\n If you see the `Failed to create subnetwork. Router status is temporarily\n unavailable. Please try again later. Help Token: [token-ID]` error\n message, try to create the Cloud SQL instance again.\n\n### Administrative issues\n\n- Only one long-running Cloud SQL import or export operation can run at a time on an instance. When you start an operation, make sure you don't need to perform other operations on the instance. Also, when you start the operation, you can [cancel it](/sql/docs/mysql/import-export/cancel-import-export).\n\n- MySQL auto-commits on each DDL statement. Cloud SQL\n persists all steps of the import up to cancelling the\n instance. Therefore, you might have to clean up the data on the\n instance manually.\n\n\u003cbr /\u003e\n\n### Issues with importing and exporting data\n\n- CSV export does not format NULLs and newlines correctly.\n\n When you export data as CSV using the Cloud SQL export feature,\n NULLs are exported as `\"N`, which can cause the CSV file to contain\n unbalanced quotation marks. Additionally, if your\n text data contains a newline character, a trailing quote mark is added\n at the end of the line.\n\n When you import a file that you exported using the default escape character,\n the file treats the value as `\"NULL\"` instead of `NULL`. To override the default\n when you export the file, use `--escape=\"5C\"`.\n\n \u003cbr /\u003e\n\n- The SQL Mode setting affects how Cloud SQL interprets SQL queries.\n\n For example, if you export from a database without Strict SQL enabled, then\n try to import to Cloud SQL (which enables Strict SQL by default), the\n import might fail. The best practice is to use the same SQL Mode on import\n that you used for export.\n\n \u003cbr /\u003e\n\n- The DEFINER clause may cause import to fail\n\n A DEFINER clause may cause an import operation to fail if the DEFINER user is\n a SUPER or system user and is different from the user doing the import into\n Cloud SQL. Learn more about [DEFINER usage](/sql/docs/mysql/import-export#definer-clause)\n and potential workarounds in Cloud SQL.\n\n \u003cbr /\u003e\n\n- If you're trying to import and export data from a large database (for example,\n a database that has 500 GB of data or greater), then the import and export\n operations might take a long time to complete. In addition, other operations\n (for example, the backup operation) aren't available for you to perform\n while the import or export is occurring. A potential option to improve the\n performance of the import and export process is to [restore a previous backup](/sql/docs/mysql/backup-recovery/restoring#projectid) using `gcloud`\n or the API.\n\n\u003c!-- --\u003e\n\n- Cloud Storage supports a [maximum single-object size up five terabytes](/storage-transfer/docs/known-limitations-transfer#object-limit). If you have databases larger than 5TB, the export operation to Cloud Storage fails. In this case, you need to break down your export files into smaller segments.\n\n### Transaction logs and disk growth\n\nLogs are purged once daily, not continuously. When the number of days of log\nretention is configured to be the same as the number of backups, a day of\nlogging might be lost, depending on when the backup occurs. For example, setting\nlog retention to seven days and backup retention to seven backups means that\nbetween six and seven days of logs will be retained.\n\nWe recommend setting the number of backups to at least one more than the days of\nlog retention to guarantee a minimum of specified days of log retention.\n\n### Issues with upgrading your MySQL instance\n\nIf you use Database Migration Service to [upgrade your MySQL instance](/sql/docs/mysql/upgrade-major-db-version-migrate) from version 5.7 to version 8.0, and you have stored procedures created in the database named `mysql` in your version 5.7 instance, then your stored procedures may not get copied to the `mysql` database in the upgraded version 8.0 instance. Also, you may not be able to create stored procedures in the `mysql` database in the upgraded instance.\n\n### Issues with InnoDB page compression\n\n[InnoDB page compression](https://dev.mysql.com/doc/refman/8.0/en/innodb-page-compression.html)\ncan improve the performance of update queries by reducing the amount of data that\nneeds to be read and written to disk. However, page compression can impact performance on the\nupdate queries on frequently updated tables. To evaluate\nthe impact of page compression on your update queries, you can run a performance\ntest with and without page compression. This helps you to observe how page\ncompression affects the performance of your workload.\n\nYou can optimize page compression performance as follows:\n\n- Use a compression algorithm suitable for your data type. For example, use LZ4\n for text data and ZLIB for binary data.\n\n- Avoid using compression for data that is frequently updated.\n Compressing and decompressing data can slow down your update queries.\n\n### Issues related to Cloud Monitoring or Cloud Logging\n\nInstances with the following region names are displayed incorrectly in certain\ncontexts, as follows:\n\n- `us-central1` is displayed as `us-central`\n- `europe-west1` is displayed as `europe`\n- `asia-east1` is displayed as `asia`\n\nThis issue occurs in the following contexts:\n\n- Alerting in Cloud Monitoring\n- Metrics Explorer\n- Cloud Logging\n\nYou can mitigate the issue for Alerting in Cloud Monitoring, and for Metrics\nExplorer, by using\n[Resource metadata labels](https://cloud.google.com/monitoring/api/v3/metric-model#meta-labels).\nUse the system metadata label `region` instead of the\n[cloudsql_database](https://cloud.google.com/monitoring/api/resources#tag_cloudsql_database)\nmonitored resource label `region`."]]
