Summary

When loading an issue, Jira gets information from every single linked issue. In cases where there are too many linked issues, overall performance to load these issues will take a hit. The Thread related to loading this issue will be reaching to the database, such as:

at org.ofbiz.core.entity.jdbc.SQLProcessor.executeQuery(SQLProcessor.java:527)
...
at com.atlassian.jira.issue.link.DefaultIssueLinkManager.getLinks(DefaultIssueLinkManager.java:343)
at com.atlassian.jira.issue.link.DefaultIssueLinkManager.lambda$new$1(DefaultIssueLinkManager.java:82)

Suggestion

Limit how many Issue Links are checked or provide a parameter to define how many records are retrieved on the initial issue loading.

Workaround

Avoid having issues with thousands of Issue Links.