1. Mirror121 High Availability Cluster

Every server (including applications running on that server) faces the potential threat of failure. Mirror121 understands how important it is for customers to have their data up-to-date without interruptions. Therefore, Mirror121 comes with a support for high availability cluster (HA).

1.1. High Availability Cluster

A high availability cluster is a group of computers which run the same application (Mirror121). When one server fails there is still the second one which can do all the work. Because of that, the potential downtime is reduced to a minimum.

Mirror121 can be installed on several servers. All the Mirror121 installations connect to the same configuration and mirror database.

If you create a synchronization on the first Mirror121 installation, the second Mirror121 installation will see the synchronization. Why? Because all the installations use the same configuration database.

ha cluster schema

1.2. Installation


  • Have two or more servers up and running.

  • Have empty databases prepared - one for configuration meta-data, the second one for the data itself. You must not use H2 embedded database.

  • Have a network drive prepared so that both servers can store activity logs to the same folder.


  1. Install the first Mirror121 to the first server. Open it in you web browser and configure Mirror121 (license, Salesforce instance, mirror database, etc.).

  2. Install the second Mirror121 to the second server. Choose the embedded H2 database. You won’t use this database is in the end. This step will install all the necessary files. You will copy the configuration from the first server.

  3. Right after the installation finishes, stop the second Mirror121.

  4. Configure the second Mirror121 to connect to the same configuration database as the first Mirror121.

    1. Connect to the first server and copy <Mirror121 Installation Folder>/mirror121/data/installationId file to the same location on the second server. This is necessary so that both Mirror121 installations can encrypt and decrypt passwords in the configuration database.

    2. Open mirror121.properties file (<Mirror121 Installation Folder>/mirror121.properties) on the first server and copy the database settings to "mirror121.properties" on the second server. More specifically, copy names and values of the following properties: "config.db.type", "config.jdbc.url", "config.jdbc.username", "config.jdbc.password", "config.jdbc.schema"

  5. Start the second Mirror121.

  6. Open Mirror121 (whichever you want) in your web browser. Set the following properties to point to a network drive which both servers can access. You don’t have to restart Mirror121 after you changed them.

    Please use UNC path on Windows machines. That is the path beginning with two backslashes. E.g. \\YourServer\Mirror121\activityLogs

    1. mirror121.activityLog.dir - path to a folder on a network drive which both servers can access. All activity logs will be stored in that folder.

    2. mirror121.attachment.rootDir - path to a folder on a network drive which both servers can access. All attachments will be stored in that folder. If you don’t synchronize attachments you don’t have to set it.

1.3. FAQ

I have two Mirror121 installations on two servers. Does that mean they execute more synchronizations in parallel?
No. The main purpose of the cluster is the high availability of Mirror121 service. Therefore, we will still execute only three synchronizations in parallel. If you want to increase the number, you have to change "mirror121.quartz.threadCount" advanced property and increase a memory available to your Mirror121.

Where do I find my activity logs?
By default, each Mirror121 installation stores the activity logs to its "<Mirror121 Installation Folder>\logs\activityLogs\" folder. That does not work in clustered environment. You have to set the activity logs folder to a network folder which both servers can access. See the image below.

ha cluster detailed

How do I know which server was used to run the synchronization?
Open an activity log of your synchronization and search for a computer name. See the image below.

ha cluster computer name

Does my license include support for HA Cluster?
Please contact our sales department at mirror121@aspectworks.com.