Jira Recovery Mode
This allows you to set a recovery password that you can use to reset the passwords for your regular adminsirators if their passwords are forgotten (or if they rely on SSO which is broken for some reason).
cp /opt/atlassian/jira-servicedesk/current/bin/setenv.sh /opt/atlassian/jira-servicedesk/current/bin/setenv.shO
vi /opt/atlassian/jira-servicedesk/current/bin/setenv.sh
Add the following argument to the JVM_SUPPORT_RECOMMENDED_ARGS parameter...
-Datlassian.recovery.password=<your-password>
For example...
JVM_SUPPORT_RECOMMENDED_ARGS="-XX:+ExplicitGCInvokesConcurrent -XX:ReservedCodeCacheSize=512M -Datlassian.recovery.password=mypassword"
Restart Jira
systemctl restart jira
Repeat for all nodes in your cluster.
If you normally use SSO, you will probably need to use the fallback login URL...
https://YourJiraServer/login.jsp?auth_fallback