Aurora MySQL 的主要版本升级预检查

预检查查询成功完成。未检测到任何不兼容性。

{
  "id": "auroraUpgradeCheckIndexLengthLimitOnTinytext",
  "title": "Check for the tables with indexes defined with prefix length greater than 255 bytes on tiny text columns",
  "status": "OK",
  "detectedProblems": []
},

预检查查询成功完成。检测到一个错误。

{
  "id": "auroraUpgradeCheckForPrefixIndexOnGeometryColumns",
  "title": "Check for geometry columns on prefix indexes",
  "status": "OK",
  "description": "Consider dropping the prefix indexes of geometry columns and restart the upgrade.",
  "detectedProblems": [
      {
        "level": "Error",
        "dbObject": "test25.sbtest1",
        "description": "Table `test25`.`sbtest1` has an index `idx_t1` on geometry column/s. Mysql 8.0 does not support this type of index on a geometry column https://dev.mysql.com/worklog/task/?id=11808. To upgrade to MySQL 8.0, Run 'DROP INDEX `idx_t1` ON `test25`.`sbtest1`;"
      },
 }

当预检查成功或失败时，可能会返回警告。

此处预检查查询成功完成。检测到两个警告。

{
  "id": "zeroDatesCheck",
  "title": "Zero Date, Datetime, and Timestamp values",
  "status": "OK",
  "description": "Warning: By default zero date/datetime/timestamp values are no longer allowed in MySQL, as of 5.7.8 NO_ZERO_IN_DATE and NO_ZERO_DATE are included in SQL_MODE by default. These modes should be used with strict mode as they will be merged with strict mode in a future release. If you do not include these modes in your SQL_MODE setting, you are able to insert date/datetime/timestamp values that contain zeros. It is strongly advised to replace zero values with valid ones, as they may not work correctly in the future.",
  "documentationLink": "https://lefred.be/content/mysql-8-0-and-wrong-dates/",
  "detectedProblems": [
      {
        "level": "Warning",
        "dbObject": "global.sql_mode",
        "description": "does not contain either NO_ZERO_DATE or NO_ZERO_IN_DATE which allows insertion of zero dates"
      },
      {
        "level": "Warning",
        "dbObject": "session.sql_mode",
        "description": " of 10 session(s) does not contain either NO_ZERO_DATE or NO_ZERO_IN_DATE which allows insertion of zero dates"
      }
    ]
}

预检查查询失败，出现一个错误，因此无法验证不兼容性。

{
  "id": "auroraUpgradeCheckForDatafilePathInconsistency",
  "title": "Check for inconsistency related to ibd file path.",
  "status": "ERROR",
  "description": "Can't connect to MySQL server on 'localhost:3306' (111) at 13/08/2024 12:22:20 UTC. This failure can occur due to low memory available on the instance for executing upgrade prechecks. Please check 'FreeableMemory' Cloudwatch metric to verify the available memory on the instance while executing prechecks. If instance ran out of memory, we recommend to retry the upgrade on a higher instance class."
}

这一失败的原因可能是实例意外重新启动，或数据库上正在运行的兼容性预检查查询被中断。例如，在较小的数据库实例类上，当实例上的可用内存不足时，可能会遇到这种情况。

在运行预检查时，可以使用 FreeableMemory Amazon CloudWatch 指标来验证实例上的可用内存。如果实例内存不足，建议在更大的数据库实例类上重试升级。在某些情况下，可以使用蓝绿部署。这支持在独立于生产工作负载的“绿色”数据库集群上运行预检查和升级，但这也会消耗系统资源。

有关更多信息，请参阅排查 Aurora MySQL 数据库的内存使用问题。

兼容性预检查还包含有关源 Aurora MySQL 版本和目标 Aurora MySQL 版本的信息，以及位于预检查输出末尾的错误、警告和通知计数摘要。

例如，以下输出显示有人尝试从 Aurora MySQL 2.11.6 升级到 Aurora MySQL 3.07.1。此升级返回了一个错误、三个警告，但没有返回任何通知。由于返回错误时无法继续升级，因此必须解决 routineSyntaxCheck 兼容性问题并重试升级。

{
  "serverAddress": "/tmp%2Fmysql.sock",
  "serverVersion": "5.7.12 - MySQL Community Server (GPL)",
  "targetVersion": "8.0.36",
  "auroraServerVersion": "2.11.6",
  "auroraTargetVersion": "3.07.1",
  "outfilePath": "/rdsdbdata/tmp/PreChecker.log",
  "checksPerformed": [{
      ... output for each individual precheck ...
      .
      .
      {
        "id": "oldTemporalCheck",
        "title": "Usage of old temporal type",
        "status": "OK",
          "detectedProblems": []
      },
      {
        "id": "routinesSyntaxCheck",
        "title": "MySQL 8.0 syntax check for routine-like objects",
        "status": "OK",
        "description": "The following objects did not pass a syntax check with the latest MySQL 8.0 grammar. A common reason is that they reference names that conflict with new reserved keywords. You must update these routine definitions and `quote` any such references before upgrading.",
        "documentationLink": "https://dev.mysql.com/doc/refman/en/keywords.html",
        "detectedProblems": [{
            "level": "Error",
            "dbObject": "test.select_res_word",
            "description": "at line 2,18: unexpected token 'except'"
        }]
      },
      .
      .
      .
      {
        "id": "zeroDatesCheck",
        "title": "Zero Date, Datetime, and Timestamp values",
        "status": "OK",
        "description": "Warning: By default zero date/datetime/timestamp values are no longer allowed in MySQL, as of 5.7.8 NO_ZERO_IN_DATE and NO_ZERO_DATE are included in SQL_MODE by default. These modes should be used with strict mode as they will be merged with strict mode in a future release. If you do not include these modes in your SQL_MODE setting, you are able to insert date/datetime/timestamp values that contain zeros. It is strongly advised to replace zero values with valid ones, as they may not work correctly in the future.",
        "documentationLink": "https://lefred.be/content/mysql-8-0-and-wrong-dates/",
        "detectedProblems": [{
            "level": "Warning",
            "dbObject": "global.sql_mode",
            "description": "does not contain either NO_ZERO_DATE or NO_ZERO_IN_DATE which allows insertion of zero dates"
            },
            {
            "level": "Warning",
            "dbObject": "session.sql_mode",
            "description": " of 8 session(s) does not contain either NO_ZERO_DATE or NO_ZERO_IN_DATE which allows insertion of zero dates"
            }
          ]
       },
       .
       .
       .
  }],
  "errorCount": 1,
  "warningCount": 3,
  "noticeCount": 0,
  "Summary": "1 errors were found. Please correct these issues before upgrading to avoid compatibility issues."
}