The Salt Master maintains a job cache of all job executions which can be queried via the jobs runner. The way this job cache is managed is very pluggable via Salt's underlying returner interface.
A number of options are available when configuring the job cache. The default caching system uses local storage on the Salt Master and can be found in the job cache directory (on Linux systems this is typically /var/cache/salt/master/jobs). The default caching system is suitable for most deployments as it does not typically require any further configuration or management.
The default job cache is a temporary cache and jobs will be stored for 24 hours. If the default cache needs to store jobs for a different period the time can be easily adjusted by changing the keep_jobs parameter in the Salt Master configuration file. The value passed in is measured via hours:
Many deployments may wish to use an external database to maintain a long term register of executed jobs. Salt comes with two main mechanisms to do this, the master job cache and the external job cache. The difference is how the external data store is accessed.
New in version 2014.7.
The master job cache setting makes the built in job cache on the master modular. This system allows for the default cache to be swapped out by the Salt returner system. To configure the master job cache, set up an external returner database based on the instructions included with each returner and then simply add the following configuration to the master configuration file:
The external job cache setting instructs the minions to directly contact the
data store. This scenario is helpful when the data store needs to be made
available to the minions. This can be an effective way to share historic data
across an infrastructure as data can be retrieved from the external job cache
ret execution module.
To configure the external job cache, set up a returner database in the manner described in the specific returner documentation. Ensure that the returner database is accessible from the minions, and set the ext_job_cache setting in the master configuration file: