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.

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

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: