On 2/6/2015 2:25 PM, Matheus de Oliveira wrote:
>
> On Fri, Feb 6, 2015 at 4:53 PM, John Scalia <jayknowsunix(at)gmail(dot)com <mailto:jayknowsunix(at)gmail(dot)com>> wrote:
>
> We have a python script called by cron on an hourly basis to back up our production database. Currently, the script invokes pg_dump and takes more than hour to complete.
> Hence the script looks to see if it's already running and exits if so. I want to change the script so it uses pg_basebackup instead since that's so much faster.
>
>
> Have you considered using incremental backup (continuous archiving) instead of a such small backup window?
>
> See [1]
>
> My problem is, however, that while I'd like to just have it build a tarball, maybe compressed, I can't use a "-X s" option for the wal segments. I think I understand why I
> can't use the streaming option with a "-Ft" specified. I'm just concerned about the docs saying that the backup may have problems with fetch as a wal segment may have
> expired. Manually testing is showing that the Db needs about 11 minutes to backup with pg_basebackup, and our wal_keep_segments setting is 6. This said, an hour's worth of
> wal segments should be available, but the six that were there at the beginning of the backup are not the same six there at the end. I don't think this is really a problem,
> but I'd like to get it confirmed. Wouldn't the backup actually have to take more than hour for this to be an issue?
>
>
> If you use archiving [1], you don't need to worry about saving the segments withing the backup, just let it be done through archive_command. Isn't that an option for you? If
> don't, why?
>
Oh, yes, I did fail to mention that the system where I'm trying this is the primary in a streaming replication cluster with (2) hot standby servers. I've mentioned without much
traction, that we don't really even need a backup with 3 servers ready to do the work without delays. Like I said in the last post, it's all political.
>
> [1] http://www.postgresql.org/docs/current/static/continuous-archiving.html
>
> Best regards,
> --
> Matheus de Oliveira
> Analista de Banco de Dados
> Dextra Sistemas - MPS.Br nível F!
> www.dextra.com.br/postgres <http://www.dextra.com.br/postgres/>
>