---
title: "CPU threads allocated to high and low priority queues."
canonical: "https://support.appfire.com/space/DLP/1197998092/CPU%20threads%20allocated%20to%20high%20and%20low%20priority%20queues."
format: markdown
---
## **CPU threads **

> 📝 Jira Data Center only.

There are two parameters controlling the number of CPU threads allocated to high-priority and low-priority queues. These parameters are defined in the bigpicture.properties file in the “plugins” directory (located in the shared folder of the selected instance).

| **Parameter** | jiraServerExtTaskQuerySingleJobExecutorMaxThreadPoolSize |
| --- | --- |
| Option a) | defines the number of CPU threads for the high-priority queue<br>(values from 4 to 1, default = 3), when the new queue division is enabled  
(PartialSyncPrioritizedQueueEnabled parameter is set to “true”) |
| Option b) | defines the number of CPU threads for the Partial Sync mechanism (values from 5 to 1, default = 5), when the new queue division is disabled (PartialSyncPrioritizedQueueEnabled parameter is set to “false”) |

| **Parameter** | jiraServerExtTaskQueryLowPrioritySingleJobExecutorMaxThreadPoolSize |
| --- | --- |
| Option a) | defines the number of CPU threads for the low-priority queue<br>(values from 4 to 1, default = 2), when the new queue division is enabled  
(PartialSyncPrioritizedQueueEnabled parameter is set to “true”) |
| Option b) | ignored when the new queue division is disabled<br>(PartialSyncPrioritizedQueueEnabled parameter is set to “false”) |

Additional note - the sum of threads divided into queues cannot exceed 5 threads, otherwise the default values will be used (3 CPU threads for the high-priority queue and 2 CPU threads for the low-priority queue). Examples of correct configurations:

jiraServerExtTaskQuerySingleJobExecutorMaxThreadPoolSize = 4  
jiraServerExtTaskQueryLowPrioritySingleJobExecutorMaxThreadPoolSize = 1

or

jiraServerExtTaskQuerySingleJobExecutorMaxThreadPoolSize = 2  
jiraServerExtTaskQueryLowPrioritySingleJobExecutorMaxThreadPoolSize = 2

If the low-priority queue is disabled due to PartialSyncLowPriorityQueueDisabled set to “true”, CPU threads allocated to this queue will not be used (i.e. only 3 CPU threads allocated to the high-priority queue will be used).