Some thoughts on the external recovery lock helper
realrichardsharpe at gmail.com
Fri Jun 17 15:16:21 UTC 2016
On Fri, Jun 17, 2016 at 8:10 AM, Ira Cooper <ira at wakeful.net> wrote:
> On Fri, Jun 17, 2016 at 10:56 AM, Richard Sharpe
> <realrichardsharpe at gmail.com> wrote:
>> OK, so this part is the harder part. If the parent crashes then the
>> helper needs to exit. It is not impossible, but a design where the
>> helper is called as a (shared) library function gets this for free. We
>> have lots of experience with this sort of thing in Samba.
>> However, it is not impossible.
> Shouldn't we be able to detect that the pipe/socket that we are writing to
> has closed?
(Replied on-list this time.)
Maybe so, however, what about a failure where the ctdb process is in
an infinite loop somewhere and not responding to election requests,
but is holding the lock. The external process thus does not get
informed to release the lock.
Of course, we could add keep-alives :-)
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