Before using TencentDB for MySQL, you need to consider the two questions:
You don't need to worry about the daily maintenance and adjustment of MySQL, which is taken care of by the OPS system of TencentDB.
In case of an exception with MySQL, the OPS system can immediately identify the issue and notify the OPS team. Developers will not need to make any changes.
Yes.
No, because the standards for splitting databases and tables are subject to your specific business logic.
Used capacity: includes only MySQL's data directories but not logs such as binlog, relaylog, undolog, errorlog, and slowlog.
Occupied capacity: includes MySQL's data directories and logs such as binlog, relaylog, undolog, errorlog, and slowlog.
Question:
If multiple SQL statements are sent to TencentDB for execution within a very short period of time, will TencentDB for MySQL run them one by one or crash? What is the maximum number of allowed concurrent connections?
Answer:
A TencentDB for MySQL instance works in the same way as a self-built MySQL instance. Whether concurrently executed statements will cause a crash depends on system resources and SQL statements themselves.
When the number of connections reaches the limit (max_connections
), the instance will not provide services normally. This happens generally due to the following reasons:
For more information, please see Use Limits.
The default replica cannot be read from or written to. It is primarily used for high-availability switchover.
CPU utilization, memory utilization, and disk space utilization. You can configure alarms as needed, and when you receive alarms, you can take corresponding measures to resolve them.
For database security purposes, TencentDB for MySQL doesn't allow you to read from or write to the replica. This allows you to, for example, quickly switch to the replica when the source fails.
If you need greater read/write capability, please consider upgrading the instance configuration or purchasing a read-only instance.
You can use MySQL v5.5 to support MyISAM. However, we recommend that you choose a higher version like MySQL v5.7. This is because the InnoDB engine in higher versions can provide row-level locking with a finer granularity, deliver higher write performances, guarantee data integrity, and avoid data loss in case of database failure.
Cross-region access is unavailable for instances in VPCs by default, as VPCs in different regions are isolated from each other. We recommend that you purchase TencentDB for MySQL instances in the same region as your CVM instances to enable local data access that guarantees high service speed and stability.
The "shutdown" and "file" permissions are unavailable to root users now, so a root user cannot create users with all permissions. Please refer to the following commands for authorization:
grant SELECT,INSERT, UPDATE, DELETE, CREATE, DROP, ALTER on *.* to 'myuser'@'%' identified by 'mypasswd';
Region modification is currently not available. You can use DTS to migrate data between instances in different regions. DTS supports real-time data sync. After data migration is completed, you can return the source instance via self-services.
User data (excluding backup data), the data needed for the instance to run (including the system database, database logs, indexes, etc.), and the binlogs generated by MySQL databases.
The maximum number of databases and tables you can create in a TencentDB for MySQL instance depends on MySQL. For more information, please see MySQL’s official documentation.
No. Currently, only two-node instances can be upgraded to three-node instances.
Probably because the instance is running MySQL v5.6 or v5.7 which only support InnoDB. To support MyISAM, please use MySQL v5.5.
By default, up to 5 RO groups can be created for a source instance.
Yes. Please pay attention to the following when using Canal:
binlog_row_image=FULL
and binlog_format=ROW
. TencentDB for MySQL instances are deployed on physical clusters with the virtualization technology. Different from physical clusters, CVMs are mainly used to provide a scalable cloud computing service.
No, because TencentDB clones an instance by pulling the backup data. After cloning is completed, the original instance can be used normally, or terminated if you don't need it any more.
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