munin-cgi-graph can "hang" due to a previous crash
|Reported by:||purewhite||Owned by:||nobody|
Due to semaphores, the perl cgi can sit waiting forever if a previous crash doesn't clear the semaphores.
A server (apache) crash meant the semaphores didn't get cleared, even though the processes had ended. I don't understand semaphores enough to know why they didn't get cleared, as my understanding is that they should get cleared if the process dies.
Clearing the semaphore manually with ipcs and ipcrm allowed munin-cgi-graph to work again. Previously it would "timeout".
#814 seems to be on the right track with SEM_UNDO. Not sure of other methods to make this work.