On Wed, Jul 27, 2016 at 3:34 AM, Achilleas Mantzios < ach...@matrix.gatewaynet.com> wrote:
> On 27/07/2016 10:15, Condor wrote: > >> On 26-07-2016 21:04, Dorian Hoxha wrote: >> >>> Many comments: https://news.ycombinator.com/item?id=12166585 >>> >>> https://www.reddit.com/r/programming/comments/4uph84/why_uber_engineering_switched_from_postgres_to/ >>> >>> On Tue, Jul 26, 2016 at 7:39 PM, Guyren Howe <guy...@gmail.com> wrote: >>> >>> Honestly, I've never heard of anyone doing that. But it sounds like >>>> they had good reasons. >>>> >>>> https://eng.uber.com/mysql-migration/ >>>> >>>> Thoughts? >>>> >>>> -- >>>> Sent via pgsql-general mailing list (pgsql-general@postgresql.org) >>>> To make changes to your subscription: >>>> http://www.postgresql.org/mailpref/pgsql-general >>>> >>> >> >> They are right for upgrades. >> It's a hard to shutdown 1 TB database and wait couple of days pg_upgrade >> to finish upgrade and meanwhile database is offline. >> In some distros after upgrade of PG version you don't have old binary and >> library, need to do full dump and restore that take time and disk space. >> > > Our last 1TB upgrade from 9.0 -> 9.3 went like a charm in something like > seconds. (with the -k option) > However, be warned that the planing and testing took one full week. > That being said, it doesn't really provide a back-out plan. The beauty of replication is that you can halt the upgrade at any point if need be and cut your (hopefully small) losses. If you use -k, you are all in. Sure, you could setup a new standby, stop traffic, upgrade whichever node you'd like (using -k) and still have the other ready in the event of total catastrophe. More often than not, I see DBAs and sysads lead the conversation with "well, postgres can't replicate from one version to another, so instead.... " followed by a fast-glazing of management's eyes and a desire to buy a 'commercial database'. All in all, Evan's blog seemed to start out decently technical, it quickly took a turn with half-truths, outdated information and, in some cases, downright fud: "The bug we ran into only affected certain releases of Postgres 9.2 and has been fixed for a long time now. However, we still find it worrisome that this class of bug can happen at all. A new version of Postgres could be released at any time that has a bug of this nature, and because of the way replication works, this issue has the potential to spread into all of the databases in a replication hierarchy." ISTM that they needed a tire swing <http://i0.wp.com/blogs.perficient.com/perficientdigital/files/2011/07/treecomicbig.jpg> and were using a dump truck. Hopefully they vectored somewhere in the middle and got themselves a nice sandbox. --Scott > > >> >> Regards, >> Hristo S. >> >> >> >> >> >> > > -- > Achilleas Mantzios > IT DEV Lead > IT DEPT > Dynacom Tankers Mgmt > > > > > -- > Sent via pgsql-general mailing list (pgsql-general@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general > -- -- Scott Mead Sr. Architect *OpenSCG <http://openscg.com>* http://openscg.com
