Data Synchronization

Each standby node automatically synchronizes its data with the data on the active node to ensure that it is constantly ready to take control of the cluster. The standby nodes perform two types of synchronization:

In addition, a few special files are synchronized outside the remote restore and ongoing updates processes. The following table provides details about how the various types of files used by Vocera are synchronized:

Table 1. Synchronized files

Type of Data

Synchronization Details

The configuration database

  • Completely updated during remote restore.

  • Kept in sync incrementally during ongoing updates.

Text, voice, and email messages

  • Completely updated during remote restore.

  • Kept in sync incrementally during ongoing updates.

All user recordings, such as learned names, learned commands, and so forth

  • Completely updated during remote restore.

  • Kept in sync incrementally during ongoing updates.

Vocera Report Server logs

  • Existing log files are copied to standby nodes during remote restore.

  • The current log file is copied to standby nodes at one-minute intervals, independently of remote restore.

  • The current log file is copied to the standbys when the Vocera Voice Server closes the file.

  • If a failover occurs, the current log file is never more than one minute old, and all previous log files are already on the standby nodes.

The badge.properties file

  • Copied to standby nodes during remote restore.

  • Loaded into memory automatically when a standby node becomes active.

Best Practice: Modify badge.properties on the active node, and then restart the active node. This action loads badge.properties into memory on the active node and forces the standby nodes to perform a remote restore and synchronize it.

Backup files

  • Backup files are synchronized outside the remote restore and ongoing updates processes.

  • Standby nodes perform a backup whenever the active node performs a backup.

    More efficient than copying large zip files across the net.

Best Practice: Perform a backup after bringing the cluster online. All nodes will then start with the same backup file.

Several types of files are intentionally not synchronized by the Vocera Voice Server during any process. The following table provides details about these files:

Table 2. Unsynchronized files

Type of Data

Reason not Synchronized

The properties.txt file

  • Each Vocera Voice Server may require hardware-dependent settings in properties.txt.

  • Each Vocera Voice Server may require different logging parameters in properties.txt.

Vocera Voice Server logs

  • Every node creates its own set of server logs.

    The logs are specific to each node and the state it is in at any given time.

  • Nodes communicate constantly and often log similar events.

    For example, the logs of both the standby and active node record that the standby node performs a remote restore. Similarly, the logs of both nodes record when a standby node rejoins a cluster after completing a remote restore.

Third-party (Tomcat, Apache, MySQL, and Nuance) logs

  • Logs provide details for troubleshooting the specific application on the specific server.

  • Processes are not managed by the VS cluster communication.

  • Files are not relevant from one machine to another.