MySQL/Oracle/PostgreSQL Monitoring

Introduction

A MySQL/Oracle/PostgreSQL monitor detects your database status, and automatically triggers traffic switching when the database is abnormal.

This section describes these three monitors because they share the same operations.

Creating a Monitor

1. Log in to the MAS console. On the Multi-Active Instances page, click an instance whose namespace type is Intra-city multi-active.
2. Click the Monitor List tab and click Create Monitor.
3. Configure the basic information, then click Next: Data Centers.
   Figure 1 Basic information configurations
   

   Table 2 Basic information parameters

   Parameter	Description
   Monitor	Select a monitor type. MySQL Oracle PostgreSQL Monitor NOTE: Ensure that you have enabled the corresponding features in functions module settings, and have selected these features when creating the namespace for your instance. Otherwise, you will not see these options.
   Application	Select the application.
   Monitor Name	Customize the monitor name.
   Exception Notification	By default, this option is disabled. If it is enabled, Monitor and database exceptions will be sent to you in a timely manner with the Huawei Cloud SMN service. Configure a secret key first. Cloud Eye is enabled by default. Ensure that the alarm rules for MAS have been created on the Cloud Eye console. For details, see Creating an Alarm Rule to Monitor an Event.
   Subject	If Exception Notification is enabled, select a subject from the drop-down list or click Add to create a new one.
   Monitoring	The default value is Yes. If No, database exceptions will not be monitored.
   Automatic Switchover	The default value is Yes. If No, automatic switchover of the databases will not be triggered.
   Username	Enter the username for logging in to the database.
   Password	Enter the password for logging in to the database.
   Confirm Password	Enter the password again.
   Associate with DRS	By default, this option is disabled. If it is enabled, the Data Replication Service (DRS) real-time DR tasks will be associated. Configure a secret key before enabling this option.
   Multi-Active Area	Select the multi-active area where the instance's namespace belongs to. NOTE: This option is displayed only when Associate with DRS is enabled.
   DRS Task	If Associate with DRS is enabled, select a real-time DR task from the drop-down list or click Add to create a new one.

4. Configure the data centers, then click Next: Databases.
   Figure 2 Data center configurations
   

   Table 3 Data center parameters

   Parameter	Description
   Cloud	The environment where the monitored database is deployed
   Region	The region where the monitored database is located
   IPv4 Address	The IP address and port number for accessing the database
   Add Read Database	Click to add the read database address.

5. Configure the databases, then click Next: Advanced.
   Figure 3 Database configurations
   

   Table 4 Database parameters

   Parameter	Description
   Monitored Database	Enter the monitored database name.
   Connected Database	Enter the connected database name.

6. Configure the advanced settings, then click Next: Confirm.
   Figure 4 Advanced configurations
   

   Table 5 Advanced settings

   Parameter	Description
   Retry Interval (ms)	The interval of reconnection attempts, in milliseconds. Default value (recommended): 3000 Value range: 1 to 300,000
   Monitoring Timeout (ms)	The timeout duration before a monitor becomes abnormal, in milliseconds. Default value (recommended): 40,000; Value range: 1 to 600,000 NOTE: Ensure that the time you specify here is longer than the time required for data center 1 to synchronize data to data center 2. Otherwise, the data in data center 2 may be incomplete.
   Database Access Timeout (ms)	The database access timeout duration, over which the database access is considered failed, in milliseconds. Default value (recommended): 3000 Value range: 3000 to 100,000

7. Confirm settings and click Create.
   

   If the created monitor is not normal, that is, its indicator is not green, its configurations or databases may be abnormal. In this case, rectify the fault.

Configuring the Connection Pool

1. Log in to the MAS console. On the Multi-Active Instances page, click an instance to go to its console.
2. Click the Monitor List tab and choose More > Configure Connection Pool in the row that contains the target monitor.
3. Set the configurations and click OK.

   Table 6 Connection pool parameters

   Parameter	Description
   Database Name	Enter the name of the connected database.
   Routing Algorithm	Options: Single read/write and Single write, local read
   Data Source	Customize a name for the data source.
   Database Address	Connection address of the database
   Schema	Name of the schema to be connected
   Load Balancing Algorithm	Options: Random and Polling
   Add Data Source	Configure the secondary/standby data source.

Configuring the Database Read/Write

To disable the database to write, interconnect the application with the DB-SDK of the Java 1.2.6-RELEASE or later version.

1. Log in to the MAS console. On the Multi-Active Instances page, click an instance to go to its console.
2. Go to the Monitor List tab page.
3. Click in the row of a data center.
   Figure 5 Configuring the database read/write
   

4. Select a new status and click OK.

   Table 7 Database read/write parameters

   Parameter	Description
   Readable	Whether the database is readable. Readable: The database status is normal and can be read. Unreadable: The database status is abnormal and cannot be read. In this case, you need to change the database status.
   Writable	Whether the database is writable. Writable: You can write data to the database. Unwritable: You cannot write data to the database.

   

   If DC 1 (active) is abnormal, MAS automatically sets DC 2 to active and sets DC 1 to Unreadable. If you need to set DC 1 to active after it recovers, you will need to click Switch Back and set DC 1 to Readable.