Fix sys:get_status/1 noproc crash during release installation #822
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ftr, i deployed this change and have successfully done upgrades with it. am yet to hit the condition where it would have crashed, during normal upgrades. |
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The summary line of the commit message is too long and/or ends with a "." Bad message: Fix sys:get_status/1 noproc crash during release installation I am a script, I am not human |
When release_handler_1:get_supervised_procs/0 does a recursive walk of the supervision tree, it calls sys:get_status/1 on supervisors, to check if they are suspended or running. This fixes a race condition where a list of supervisor pids is gathered, one of them (legitimately) exits before release_handler can examine it, then sys:get_status/1 is called with a dead pid, causing an exit(noproc) See: http://erlang.org/pipermail/erlang-questions/2015-August/085712.html (To recreate this problem for testing, I added a timer:sleep into the release_handler_1 code, and killed a supervisor during get_supervised_procs being called).
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Patch has passed first testings and has been assigned to be reviewed I am a script, I am not human |
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Looks good. I did a minor fix to the text in the warning message, and added the PR to our nightly tests. Thanks! |
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Test ok for five nights. Including PR in OTP-18.3. |
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When release_handler_1:get_supervised_procs/0 does a recursive walk of
the supervision tree, it calls sys:get_status/1 on supervisors, to check
if they are suspended or running.
This fixes a race condition where a list of supervisor pids is gathered,
one of them (legitimately) exits before release_handler can examine it,
then sys:get_status/1 is called with a dead pid, causing an exit(noproc)
See: http://erlang.org/pipermail/erlang-questions/2015-August/085712.html
(To recreate this problem for testing, I added a timer:sleep into the
release_handler_1 code, and killed a supervisor during
get_supervised_procs being called).