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Thirdlane

Data Sync Architecture

Data Sync is the mechanism that turns a change you save in Configuration Manager into live configuration on the servers that actually handle calls. Understanding it helps you answer the question every administrator eventually asks: “I saved my change - why hasn’t it taken effect yet?” When you make a change, the system automatically generates configuration files and applies them. In an all-in-one deployment this happens instantly on the same server. In a cluster, the change must be synchronized out to every server before it takes effect, which is where most “my change did not apply” situations originate.

How It Works

  1. You save a change in Configuration Manager
  2. The change is recorded with a version number
  3. Configuration files are regenerated
  4. Commands are queued (e.g., reload PBX dialplan, refresh Kamailio routing)
  5. The sync agent (cacher) picks up the commands and executes them

In cluster mode, the regenerated files are copied out to the other servers before the commands run, and each server runs its own sync agent that processes only its own commands.

This is not the same thing as publishing the cluster’s description. Data sync carries configuration - dialplans, routing, tenant settings - to servers that already exist. Which servers exist and what each one is, is published separately from Cluster Configuration.

Monitoring Sync Status

Use Data Sync (under Tools > Data Sync) to check:

  • Whether the sync agent is running on each server
  • Current sync version per server vs. the latest configuration version
  • Any pending or failed commands

The Change Log shows all configuration changes with version numbers, useful for correlating issues with specific changes.

Troubleshooting

Common sync issues:

  • Sync agent not running — check with systemctl status cacher on the affected server
  • Server version behind — the server may have missed commands; check cacher logs
  • Files not arriving (cluster only) — the file copy runs on the manager, so check there first; Data Sync reports which servers are behind