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Setup GE Digital APM Server - High Availability Configuration

If GE Digital APM Servers are set up in a load-balanced configuration, then two Redis servers should be running, each on a separate system, with each GE Digital APM server/service configured to point to the separate systems. Redis servers can be configured either by Replication only Setup or by Automatic Fail-Over monitoring.

The first Redis server setup is used for caching. The second Redis server setup is used by GE Digital APM Scheduling Service to broadcast events to instances of GE Digital APM.

Redis - High Availability Configuration

The following image illustrates how the Redis server setup used by GE Digital APM Scheduling Service communicates with instances of GE Digital APM over web socket protocol.

Redis server and web socket protocol

Replication only Setup

Redis can be configured with replication only. Replication only setup means that Redis will replicate data automatically to any configured slaves but in the event of a failure, an administrator must login and manually change a server to be master instead of slave.

A number of changes are needed in the Redis configuration file. To enable the Redis master-slave configuration:

Steps: Changes to the MasterClosed

  1. Configure the save intervals.

    save 900 1

    save 300 10

    save 60 10000

  2. Configure the directory for the persisted data.

    heapdir "c:\\path_to_where_data_is_stored\\"

  3. Enable peristence.

    persistence-available yes

Steps: Changes to the SlaveClosed

  1. Configure the slave to point to the master IP address.

    slaveof <masterip> <masterport>

  2. Configure the slave priority to a lower value than the master.

    slave-priority 1

    Note: The default priority is 100. You should configure the first slave and set the priority to 1, then set the priority of the second slave to 2, and so on.

Steps: Automatic fail-over monitoring and configuration

In this type of setup, the setup will automatically replicate any data changes from the master to the slave. Sentinel will then automatically detect a failure and re-configure the Redis slave to be the master in the event of a failure.

Note: It is is recommended that Redis be configured in a master/slave setup with Sentinel.

  1. Install Sentinel using the Redis server executable file.

  2. Make changes to the Sentinel "Conf" file:

    redis-server --service-install sentinel.windows.conf --loglevel verbose --service-name Sentinel --sentinel

  3. Configure the port in the Sentinel "conf" file.

    Note: By default, the Redis server runs on TCP Port 6379. If using in a non-secure network then the port should be blocked from external access but be accessible from all other sentinels and all Redis servers. Sentinels should be 1 more than the number of slaves.

  4. To use GE Digital APM, Redis, and Sentinel in a High Availability Configuration:

    1. On the GE Digital APM Server machine, navigate to the folder C:\ProgramData\Meridium.

    2. Open the file MeridiumAppSettings.xml in an application that you can use to modify XML script (e.g., Notepad).

    3. Within the <Cache Service> tag, make changes to the following setting:

      • cacheServiceUrl- This should contain connection details to the Redis server setup that will be used for caching. The servers are separated by a comma at the beginning of the connection string and should include the port number, if non-default ports are used.

    4. Within the <appSettings> tag, make changes to following settings:

      • useRedisBackplane : This should be set to true.

      • redisBackplaneUrl : This should contain connection details to the Redis server setup that will be used by GE Digital APM Scheduling Service. The servers are separated by a comma at the beginning of the connection string, and, if non-default ports are used, should include the port number.

    5. For each GE Digital APM Server in the high-availability configuration, repeat steps a through d.

    Note: All servers (GE Digital APM, Redis, and Sentinel) in a High Availability configuration must use the same password.

Related Information

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