Modify Backbone thread pool parameters
Before you begin
You have to have access to the file system of your Jira server to follow the steps laid out in this article.
Backbone Issue Sync uses an internal thread pool to run all synchronizations. Each synchronization requires two threads to run. Backbone is using pre-defined values for the internal Java thread pool it creates. In rare cases, you may need to overwrite the defaults, e.g. if you have a large number of synchronizations. You can do so by defining the following system properties:
Representing the maximum number of threads that Backbone is allowed to create. By default, this property is set to 10.
If at any point Backbone is using all the available threads, then new tasks will stack up in a queue till a thread is available for a new task. This parameter represents the maximum size of that queue. By default, this property is set to 1000.
Don't overwrite those parameters unless you have an absolute need to do so.
Add the following system properties to your start script of Jira.