On Tue, Aug 7, 2012 at 2:22 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Robert Haas <robertmh...@gmail.com> writes: >> We just had a customer hit a very similar problem on 9.1.3, running on >> Windows Server 2008 SP2. ... >> The customer finds that they can reproduce this on a variety of >> systems under heavy load. > >> Now, it looks to me like for this stack trace to happen, >> PgstatCollectorMain() has got to call pgwin32_waitforsinglesocket (at >> line 3002), and that function has to return true, so that got_data >> gets set to true. Then PgstatCollectorMain() will call recv(), which >> on Windows will really be pgwin32_recv, which will call >> pgwin32_waitforsinglesocket, which must now hang. The fact that the >> first pgwin32_waitforsinglesocket call returned true should mean that >> the stats collector socket is ready for read, while the fact that the >> second one did not return seems to imply that it's not ready for read, >> close, or accept. So it almost looks like Windows can change its mind >> about whether the socket is readable. > >> Or maybe we're telling it to change its mind. This sounds an awful >> lot like something that could have been caused by the oversights fixed >> in commit b85427f2276d02756b558c0024949305ea65aca5. Was there a >> reason we didn't back-patch that? > > Sure: it was unproven that that fixed anything at all, much less that it > was bug-free enough to be safe to backpatch. Neither of those things > has changed since May. If you want you can try making up a 9.1 with > those changes and giving it to this customer to see if it fixes their > problems --- but without some field testing of the sort, I'm pretty > hesitant to put it into back branches.
Well, we had the customer try out 9.2beta, and they were unable to reproduce the issue there. Woo-hoo. Does that qualify as sufficient evidence for back-patching this? (BTW, I think commit 9b63e9869ffaa4d6d3e8bf45086a765d8f310f1c contains a thinko in one of the comments: shouldn't "a crock of the first water" be "a crock of the first order"?) -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs