Re: [HACKERS] [GENERAL] 9.4.1 - 9.4.2 problem: could not access status of transaction 1
Just wanted to report that I rolled back my VM to where it was with 9.4.2 installed and it wouldn't start. I installed 9.4.4 and now it starts up just fine: 2015-06-12 16:05:58 PDT [6453]: [1-1] LOG: database system was shut down at 2015-05-27 13:12:55 PDT 2015-06-12 16:05:58 PDT [6453]: [2-1] LOG: MultiXact member wraparound protections are disabled because oldest checkpointed MultiXact 1 does not exist on disk 2015-06-12 16:05:58 PDT [6457]: [1-1] LOG: autovacuum launcher started 2015-06-12 16:05:58 PDT [6452]: [1-1] LOG: database system is ready to accept connections done server started And this is showing up in my serverlog periodically as the emergency autovacuums are running: 2015-06-12 16:13:44 PDT [6454]: [1-1] LOG: MultiXact member wraparound protections are disabled because oldest checkpointed MultiXact 1 does not exist on disk **Thank you Robert and all involved for the resolution to this.** With the fixes introduced in this release, such a situation will result in immediate emergency autovacuuming until a correct oldestMultiXid value can be determined Okay, I notice these vacuums are of the to prevent wraparound type (like VACUUM FREEZE), that do hold locks preventing ALTER TABLEs and such. Good to know, we'll plan our software updates accordingly. Is there any risk until these autovacuums finish?
Re: [HACKERS] [GENERAL] 9.4.1 - 9.4.2 problem: could not access status of transaction 1
On Fri, Jun 5, 2015 at 11:47 AM Andres Freund and...@anarazel.de wrote: But I'd definitely like some independent testing for it, and I'm not sure if that's doable in time for the wrap. I'd be happy to test on my database that was broken, for however much that helps. It's a VM so I can easily revert back as needed. I'm just losing track of all the patches, and what's committed and what I need to manually apply :-). I was about to test what's on REL9_4_STABLE. Let me know if I should do this. Thanks so much everyone.
Re: [HACKERS] Re: [GENERAL] 9.4.1 - 9.4.2 problem: could not access status of transaction 1
On Fri, May 29, 2015 at 12:08 PM Robert Haas robertmh...@gmail.com wrote: OK, here's a patch. I grabbed branch REL9_4_STABLE from git, and Robert got me a 9.4-specific patch. I rebuilt, installed, and postgres started up successfully! I did a bunch of checks, had our app run several thousand SQL queries against it, had a colleague check it out, and it looks good. Looking at top and ps, I don't see anything funny (e.g. no processes spinning cpu, etc), things look normal. Let me know if I can provide anything else.
[HACKERS] Re: [GENERAL] 9.4.1 - 9.4.2 problem: could not access status of transaction 1
On Wed, May 27, 2015 at 3:21 PM Alvaro Herrera alvhe...@2ndquadrant.com wrote: I think a patch like this should be able to fix it ... not tested yet. Thanks Alvaro. I got a compile error, so looked for other uses of SimpleLruDoesPhysicalPageExist and added MultiXactOffsetCtl, does this look right? + (!InRecovery || SimpleLruDoesPhysicalPageExist(MultiXactOffsetCtl, pageno))) It compiled then, but it didn't seem to change anything: postgres gave the same errors and still would not start up. I'm recompiling it now just to be sure I didn't make any mistakes. I have to leave for the day in a few minutes so I thought I'd check on the above argument with you. Thanks again!
