Operations returning "The Jira server could not be contacted..."

Description

Some instances have been experiencing problems when performing different operations in Jira. This includes opening issues, opening search results (filters) and other operations.

When checking the application logs, it is possible to observe Database Exceptions related to connection pools.

How to reproduce

This behavior is intermittent

Although there does not exist a specific set of steps that can be followed to observe this behavior, it may occur when opening issues and running searches, for an example. When the problem occurs, a message saying "The Jira server could not be contacted. This may be a temporary glitch or the server may be down" is presented.

Side note

This bug should not be referenced to every single occurrence of this problem (error message), as this message may be returned in other situations as well.