Re: [HACKERS] Hot standby documentation
Markus Wanner wrote: Bruce, Bruce Momjian wrote: Ah, I now realize it only mentions warm standby, not hot, so I just updated the documentation to reflect that; you can see it here: Maybe the table below also needs an update, because unlike Warm Standby using PITR, a hot standby accepts read-only queries and can be configured to not loose data on master failure. Ahh, good point. I had not considered the table would change. What I did was to mark Slaves accept read-only queries as Hot only. You can see the result here: http://momjian.us/tmp/pgsql/high-availability.html I did not change Master failure will never lose data because the 9.0 streaming implementation is not sychronous (see wal_sender_delay in postgresql.conf), and I don't think even setting that to zero makes the operation synchronous. I think we will have to wait for PG 9.1 for _synchronous_ streaming replication. -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Hot standby documentation
On Mon, Feb 8, 2010 at 10:34 PM, Bruce Momjian br...@momjian.us wrote: Ahh, good point. I had not considered the table would change. What I did was to mark Slaves accept read-only queries as Hot only. Can the warm standby still reside in v9.0? If not, the mark of Hot only seems odd for me. I did not change Master failure will never lose data because the 9.0 streaming implementation is not sychronous (see wal_sender_delay in postgresql.conf), and I don't think even setting that to zero makes the operation synchronous. I think we will have to wait for PG 9.1 for _synchronous_ streaming replication. You are right. Regards, -- Fujii Masao NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Hot standby documentation
Fujii Masao wrote: On Mon, Feb 8, 2010 at 10:34 PM, Bruce Momjian br...@momjian.us wrote: Ahh, good point. ?I had not considered the table would change. ?What I did was to mark Slaves accept read-only queries as Hot only. Can the warm standby still reside in v9.0? If not, the mark of Hot only seems odd for me. Yes, both hot and warm standby is supported in 9.0. -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Hot standby documentation
Bruce, Bruce Momjian wrote: Ah, I now realize it only mentions warm standby, not hot, so I just updated the documentation to reflect that; you can see it here: Maybe the table below also needs an update, because unlike Warm Standby using PITR, a hot standby accepts read-only queries and can be configured to not loose data on master failure. Do we want to call the feature hot standby? Is a read-only standby a standby or a slave? I think hot standby is pretty much the term, now. Regards Markus Wanner -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Hot standby documentation
On Sun, Feb 7, 2010 at 4:41 AM, Markus Wanner mar...@bluegap.ch wrote: Bruce Momjian wrote: Do we want to call the feature hot standby? Is a read-only standby a standby or a slave? I think hot standby is pretty much the term, now. See here for the previous iteration of this discussion: http://archives.postgresql.org/pgsql-hackers/2009-08/msg00870.php I've always thought this feature was misnamed and nothing has happened to change my mind, but it's not clear whether I'm in the majority. ...Robert -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Hot standby documentation
I've always thought this feature was misnamed and nothing has happened to change my mind, but it's not clear whether I'm in the majority. I'm afraid force of habit is more powerful than correctness on this one. It's going to be HS/SR whether that's perfectly correct or not. --Josh Berkus -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Hot standby documentation
On Feb 7, 2010, at 12:35 PM, Josh Berkus wrote: I've always thought this feature was misnamed and nothing has happened to change my mind, but it's not clear whether I'm in the majority. I'm afraid force of habit is more powerful than correctness on this one. It's going to be HS/SR whether that's perfectly correct or not. What would be correct? I thought HS/SR were pretty correct (as long as no one confuses SR with synchronous replication!). Best, David -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Hot standby documentation
Joshua Tolley wrote: -- Start of PGP signed section. Having concluded I really need to start playing with hot standby, I started looking for documentation on the subject. I found what I was looking for; I also found this page[1], which, it seems, ought to mention hot standby. Comments? [1] http://developer.postgresql.org/pgdocs/postgres/high-availability.html Ah, I now realize it only mentions warm standby, not hot, so I just updated the documentation to reflect that; you can see it here: http://momjian.us/tmp/pgsql/high-availability.html Warm and Hot Standby Using Point-In-Time Recovery (PITR) Do we want to call the feature hot standby? Is a read-only standby a standby or a slave? -- Bruce Momjian br...@momjian.ushttp://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Hot standby documentation
On Thu, 2010-01-07 at 18:34 +0900, Fujii Masao wrote: On Thu, Jan 7, 2010 at 6:09 PM, Joshua Tolley eggyk...@gmail.com wrote: Having concluded I really need to start playing with hot standby, I started looking for documentation on the subject. I found what I was looking for; I also found this page[1], which, it seems, ought to mention hot standby. Comments? [1] http://developer.postgresql.org/pgdocs/postgres/high-availability.html +1 At least, it should be mentioned that the slave can answer read-only queries in Warm Standby Using Point-In-Time Recovery. And so Table 25-1 should be changed. OK, will add. -- Simon Riggs www.2ndQuadrant.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
[HACKERS] Hot standby documentation
Having concluded I really need to start playing with hot standby, I started looking for documentation on the subject. I found what I was looking for; I also found this page[1], which, it seems, ought to mention hot standby. Comments? [1] http://developer.postgresql.org/pgdocs/postgres/high-availability.html -- Joshua Tolley / eggyknap End Point Corporation http://www.endpoint.com signature.asc Description: Digital signature
Re: [HACKERS] Hot standby documentation
On Thu, Jan 7, 2010 at 6:09 PM, Joshua Tolley eggyk...@gmail.com wrote: Having concluded I really need to start playing with hot standby, I started looking for documentation on the subject. I found what I was looking for; I also found this page[1], which, it seems, ought to mention hot standby. Comments? [1] http://developer.postgresql.org/pgdocs/postgres/high-availability.html +1 At least, it should be mentioned that the slave can answer read-only queries in Warm Standby Using Point-In-Time Recovery. And so Table 25-1 should be changed. Regards, -- Fujii Masao NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
