Leek provides a separate page to track issues, giving you an idea about the different seen exceptions in each application, Leek will aggregate events by exception name and returns basic statistics, with these statistics you can track for each exception:
Occurrence - how many occurrences of the issue.
Retry - how many failed tasks are waiting to be retried.
Revoked - how many tasks were revoked.
In Progress - how many failed tasks that are in progress.
Failed - how many failed tasks.
Critical - how many critical tasks were failed after max retries.
Recovered - how many recovered tasks were succeeded after one or many retries.