All cache flushing would be nice. This request is specifically about user and password caches.

Note:

1. Custom field caches can be flushed using the Remote API
2. OptionSetManager, GenericConfigManager, FieldConfigSchemeManager and FieldConfigSchemePersister can be flushed by adding the line (at line 46):

   <%((JiraCachedManager) ComponentManager.getComponentInstanceOfType(aClass)).refreshCache();%>

   To the file <jira-install>/atlassian-jira/secure/admin/cacheViewer.jsp. (one is attached).

The user cache appears to be in ExternalEntityJiraProfileProvider, but that's not flushing from a JSP.