Thread: "hot standby" system

"hot standby" system

From
Chris Campbell
Date:
The documentation [1] says this about On-line backup and point-in- 
time recovery:

> If we continuously feed the series of WAL files to another machine  
> that has been loaded with the same base backup file, we have a "hot  
> standby" system: at any point we can bring up the second machine  
> and it will have a nearly-current copy of the database.

Is this possible today in a stable and robust way? If so, can we  
document the procedure? If not, should we alter the documentation so  
it's not misleading? I've had several people ask me where to enable  
the "hot standby" feature, not realizing that PostgreSQL only has  
some of the raw materials that could be used to architect such a thing.

Thanks!

- Chris

[1] http://www.postgresql.org/docs/8.1/interactive/backup-online.html



Re: "hot standby" system

From
"Joshua D. Drake"
Date:
> 
> Is this possible today in a stable and robust way? If so, can we 
> document the procedure? If not, should we alter the documentation so 
> it's not misleading? I've had several people ask me where to enable the 
> "hot standby" feature, not realizing that PostgreSQL only has some of 
> the raw materials that could be used to architect such a thing.

Well it works fine depending on how you set it up :) Please feel free to 
submit a patch to the docs.

Sincerely,

Joshua D. Drake


> 
> Thanks!
> 
> - Chris
> 
> [1] http://www.postgresql.org/docs/8.1/interactive/backup-online.html
> 
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Re: "hot standby" system

From
Hannu Krosing
Date:
Ühel kenal päeval, R, 2006-07-21 kell 20:00, kirjutas Chris Campbell:
> The documentation [1] says this about On-line backup and point-in- 
> time recovery:
> 
> > If we continuously feed the series of WAL files to another machine  
> > that has been loaded with the same base backup file, we have a "hot  
> > standby" system: at any point we can bring up the second machine  
> > and it will have a nearly-current copy of the database.
> 
> Is this possible today in a stable and robust way? If so, can we  
> document the procedure? If not, should we alter the documentation so  
> it's not misleading? I've had several people ask me where to enable  
> the "hot standby" feature, not realizing that PostgreSQL only has  
> some of the raw materials that could be used to architect such a thing.

We have written a management script that manages the setup und failover
procedures. It is a part of the SkyTools package we announced at the
postgresql conference in Toronto.

We failed to put it up on PgFoundry during the code sprint (it took a
whole day to enable the project there :( ) and have not had enough time
to do it after coming back. But it will be on PgFoundry eventually.

Marko has the details if you need it faster

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Hannu Krosing
Database Architect
Skype Technologies OÜ
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