Can i please know how to calculate the values for " user-level concurrent search job limit" ,"user level concurrent real time search job limit" , "limit total job disk quota" . What is the role of "limit total job disk quota" because in our environment jobs are getting queued for some users until other users jobs are completed and do the increase of "user-level concurrent search job limit" will solve the issue ( currently it is 30 )
These values are stored under Settings >> Access Controls >> Roles.
There are defaults, but you can override them for your roles. However, if you set the limits very large, it may not help. Each search requires the use of a CPU core while it is running. So it won't do anything helpful if you set the limit to a number that is larger than the number CPU cores that you have.
And if you want to increase resources to improve performance - it is very likely that you don't want to increase the number of CPU cores on the search head - if you add more indexers, searches will run faster and there will be less resource contention.