MongoDB Monitoring and DR

Introduction

A monitor detects your database status, and automatically triggers traffic switching when the database is abnormal. You can also switch the traffic manually. For details, see Step 4: Switch the MongoDB Monitor.

This section uses an example of MongoDB monitor to help you quickly get started.

The general process includes:

• Step 1: Prepare MongoDB Databases
• Step 2: Create an Application
• Step 3: Create a MongoDB Monitor
• Step 4: Switch the MongoDB Monitor

Step 1: Prepare MongoDB Databases

Prepare a MAS instance and two MongoDB databases before you start. You can use the databases bought on the Huawei Cloud official website or deployed on two local machines.

This section uses two MongoDB databases bought on Huawei Cloud as an example. Deploy the databases in different AZs of the same region for failover and high availability.

1. Prepare two MongoDB databases with the same name, username, and password. For details, see Custom Config.
2. Bind EIPs. For details, see Binding and Unbinding an EIP.
3. Configure security group rules. For details, see Configuring a Security Group. The default port for database access is 8635.

Step 2: Create an Application

Applications isolate resources of different users in an instance. Monitors must be associated with applications.

1. Log in to the MAS console. On the Multi-Active Instances page, click an instance to go to its console.
2. Click the Applications tab, and click Create.
3. Enter the application information, then click OK.

   Table 1 Application parameters

   Parameter	Description
   Application	Customize the application name.
   Description	(Optional) Enter a description about the application.

Step 3: Create a MongoDB 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 MongoDB Monitoring.
   Application	Select the application created in Step 2: Create an Application.
   Monitor Name	Customize the monitor name.
   Exception Notification	The default setting (Disabled) is used in this example. If this option is enabled, monitor and database alarms will be sent to you in a timely manner with the Huawei Cloud SMN service. Configure a secret key before enabling this option.
   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 monitored database.
   Password	Enter the password for logging in to the monitored database.
   Confirm Password	Enter the password again.

   

   Enter the username and password you configured in Step 1: Prepare MongoDB Databases.

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

   Table 3 Data center parameters

   Parameter	Description
   Cloud	Select the environments where the MongoDB databases are deployed.
   Region	Select the regions of the MongoDB databases created in Step 1: Prepare MongoDB Databases.
   Connection Address	Enter the access addresses and ports of the MongoDB databases created in Step 1: Prepare MongoDB Databases.

5. Configure the information and enter the database name you set in Step 1: Prepare MongoDB Databases, then click Next: Advanced.
   Figure 3 Database configurations
   
6. Configure the advanced settings, then click Next: Confirm. Default values are used in the following figure.
   Figure 4 Advanced configurations
   
7. Confirm settings and click Create.

Step 4: Switch the MongoDB Monitor

1. On the Monitoring List page, click Switch Over in the row of a target monitor.
2. Click OK. The active (primary) database changes from data center 1 to data center 2.
3. After the database connection and read/write in data center 1 recover, click Switch Back in the row of the target monitor.
4. Click OK. The active (primary) database changes back to data center 1.