Overview

A load balance channel allows ROMA Connect to access backend services deployed on a specified server in load balancing mode. ROMA Connect can access ECSs on the same cloud service platform as well as your own private servers.

For example, six ECSs have been deployed in a VPC, and a load balance channel has been created to reach ECS 01 and ECS 04. ROMA Connect can access these two ECSs through the load balance channel.

Figure 1 Accessing the ECSs in a load balance channel

Prerequisites

The network between ROMA Connect and the servers in the load balance channel is normal.

Procedure

1. Log in to the ROMA Connect console. On the Instances page, click View Console next to a specific instance.
2. In the navigation pane on the left, choose API Connect > API Management. On the Load Balance Channels tab page, click Create.
3. On the Create Load Balance Channel page, configure load balance channel information.
   1. Configure basic information about the load balance channel.

      Table 1 Parameters for configuring the load balance channel

      Parameter	Description
      Name	Enter a load balance channel name. It is recommended that you enter a name based on naming rules to facilitate search.
      Port	Enter the access port number in the load balance channel.
      Distribution Algorithm	Select a distribution algorithm for backend service requests. The load balance channel determines the server to which the request is to be sent based on the distribution algorithm.
      Backend Server Type	Select the member type in the load balance channel. The member type cannot be changed after the load balance channel is created. Cloud Server: Add a load balance channel member by selecting a cloud server. Server address: Add a load balance channel member by entering a server IP address. In a ROMA Site instance, server members of the instance type cannot be added.

   2. Create a server group.
      1. Click Create Server Group.
      2. In the Create Server Group dialog box, configure the group information and click OK.
         You can divide servers into multiple groups.

         Table 2 Server group configurations

         Parameter	Description
         Group Name	Name of a server group. Set this parameter as planned. It is recommended that you enter a name based on naming rules to facilitate search.
         Weight	Enter the weight of the server group. A larger weight indicates that more requests are forwarded to the server in the group.
         Description	Enter a brief description of the group.

   3. Add cloud servers or server addresses to the load balance channel based on the backend server type configured for the load balance channel.
      • Add a cloud server.
        1. Click Select ECS.
        2. In the Select ECS dialog box, select a subnet, select the ECS to be added, and click OK.
      • Add a backend server address.
        1. Click Add Backend Server Address.
        2. On the page displayed, configure backend server information.

           Table 3 Backend server information

           Parameter	Description
           Backend Server Address	Enter the IP address of the backend server.
           Standby Node	After you enable this parameter, the corresponding backend server works as the standby node only when all non-standby nodes are faulty.
           Port	Enter the access port number of the backend server. If the port number is 0, the port of the load balance channel is used.
           Indicates the enabling and disabling status.	Indicates whether to enable the server. Requests are distributed to the server only after the server is enabled.

   4. Configure the health check.

      The health check function is enabled by default. If you do not need to perform the health check, disable this parameter.

      Table 4 Health check configurations

      Parameter	Description
      Protocol	Select the protocol used for the health check. The value can be TCP, HTTP, or HTTPS.
      Two-way Authentication	This parameter is mandatory only if Protocol is set to HTTPS. Determine whether to enable two-way authentication between ROMA Connect and backend servers.
      Path	This parameter is mandatory only if Protocol is set to HTTP or HTTPS. Enter the health check URL.
      Method	This parameter is mandatory only if Protocol is set to HTTP or HTTPS. Select the HTTP request method used for the health check. The value can be GET or HEAD.
      Health Check Port	Enter the destination port of the health check. By default, the port number configured for the load balance channel is used.
      Healthy Threshold	Number of consecutive successful checks required for an ECS to be considered healthy. For example, if Healthy Threshold is set to 2, ROMA Connect considers the ECS status as healthy when the check is successful for two consecutive times.
      Unhealthy Threshold	Number of consecutive failed checks required for an ECS to be considered unhealthy. For example, if Unhealthy Threshold is set to 5, ROMA Connect considers the ECS status as abnormal when the check fails for five consecutive times.
      Timeout Interval	Enter the response timeout duration of a health check, in the unit of seconds. If no response is received within the specified duration, the health check fails.
      Interval (s)	Enter the interval between consecutive checks.
      Response Codes	This parameter is mandatory only if Protocol is set to HTTP or HTTPS. When the server returns a specified HTTP response code, the server considers the response as successful. Multiple response codes can be specified at the same time.

4. Click Finish.