Re: Possible crash on standby

On Fri, Sep 09, 2022 at 05:29:49PM +0900, Kyotaro Horiguchi wrote:
> This is because WaitForWALToBecomeAvailable doesn't call
> XLogSHutdownWalRcv() when walreceiver has been stopped before we reach
> the WalRcvStreaming() call cited above. But we need to set
> InstasllXLogFileSegmentActive to false even in that case, since no one
> other than startup process does that.

Nice find.

> Unconditionally calling XLogShutdownWalRcv() fixes it. I feel we might
> need to correct the dependencies between the flag and walreceiver
> state, but it not mandatory because XLogShutdownWalRcv() is designed
> so that it can be called even after walreceiver is stopped. I don't
> have a clear memory about why we do that at the time, though, but
> recovery check runs successfully with this.

I suppose the alternative would be to set InstallXLogFileSegmentActive to
false in an 'else' block, but that doesn't seem necessary if
XLogShutdownWalRcv() is safe to call unconditionally. So, unless there is
a bigger problem that I'm not seeing, +1 for your patch.

--
Nathan Bossart
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