Before making any changes it's crucial that you've read thee following first, then ask the question, "am I trying to solve an issue?", if this is the case reach out to the support team to ensure we're addressing the right issues.
What is Background Task Runnner?
This is all covered in the following article.
How to configure the task queue sizes
By default Yellowfin allows up to 5 background threads to be run concurrently, and 20 tasks sitting in the waiting queue.
Both of these options can be configured by editing the web.xml file (yellowfin\appserver\webapps\root\web-inf\), then restarting YF to have the changes take affect.
It's important BEFORE making any changes that you make a backup of your web.xml.
The concurrent queue size is configured via the 'TaskSchedulerThreads' , and the waiting queue size via the 'TaskSchedulerMaxThreadQueue' parameter. This all lives under the MIStartup block, and should be in there already, commented out.
Example below taken from 8.0.2
Just uncomment the relevant parameters, make your changes to the <param-value> value, save, and restart YF.
Again, it's worth mentioning that if you're looking at changing these values, there could be more to it, so please reach out to the support.