Troubleshooting Passing Grains to a Start Event

Every time a Salt client starts, it passes the machine_id grain to Uyuni. Uyuni uses this grain to determine if the client is registered. This process requires a synchronous Salt call. Synchronous Salt calls block other processes, so if you have a lot of clients start at the same time, the process could create significant delays.

To overcome this problem, a new feature has been introduced in Salt to avoid making a separate synchronous Salt call.

To use this feature, you can add a configuration parameter to the client configuration, on clients that support it.

To make this process easier, you can use the mgr_start_event_grains.sls helper Salt state.

This only applies to already registered clients. If you registered your Salt client recently, this config parameter is added by default.

On the Uyuni Server, at the command prompt, use this command to enable the start_event_grains configuration helper:

salt '*' state.sls util.mgr_start_event_grains

This command adds the required configuration into the client’s configuration file, and applies it when the client is restarted. If you have a large number of clients, you can execute the command in batch mode instead:

salt --batch-size 50 '*' state.sls mgr_start_event_grains