On 2016-04-15 19:59:06 +0100, Simon Riggs wrote: > For me, the issue is that we need to do something to catch bugs. The > existing code does not have any test at all to check whether we are doing > the wrong thing - it just lets the wrong thing happen.
But sending the message, without assigning an xid, *IS* the right thing to do here? We shouldn't assign an xid, and we need to send the message out to the standbys.
> Fixing it by forcing a new behaviour might be the right thing to do going > forwards, but I don't much like the idea of forcing new behaviour in back > branches. It might fix this bug, but can easily cause others.
What's your alternative? Assigning an xid in the middle of vacuum isn't ok, breaking vacuum isn't either?
In my understanding we have two choices for this bug
1) assign an xid so it forces sending a message (message plus xid)
2) send a message without assigning an xid (message only)
(1) seems like it is worse for backpatching, IMHO, though I am willing to hear other thoughts or options
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Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
