On 11 March 2011 12:04, Magnus Hagander <magnus@hagander.net> wrote:
> On Fri, Mar 11, 2011 at 12:58, Damien Churchill <damoxc@gmail.com> wrote:
>> Hi there,
>>
>> I have done quite a bit of searching but have been unable to find any
>> way to do this. I am quite keen to use PostgreSQL 9.0's streaming
>> replication to create a master/slave write/read setup. However I am
>> unsure of an upgrade procedure whilst using streaming replication that
>> doesn't yield any downtime (including being able to write). From what
>> I have read the WAL won't be compatible between 9.0 and 9.1 so it
>> won't be possible to take the slave off-line and upgrade it, promote
>> it to master and then upgrade the old master.
>
> That's correct, you can'd do that.
>
>
>> So I was wondering if anyone knows of a method that allows you to do
>> this. Sorry if this is an often asked question and I just haven't been
>> able to find the answer.
>
> Using SR, the method will be to upgrade the master and then rebuild
> the slave off that one. You can upgrade with pg_upgrade, which will
> shorten your downtime, but there will be downtime.
>
> For a downtime-less upgrade, you will need to look at one of the
> "userspace replication solutions", like slony, bucardo, londiste etc.
>
Thanks for the response!
That's the conclusion I had come to as well, I thought it best to ask
in case there was a method I hadn't come across. Is anything planned
to allow SR to be used for downtime-less upgrades, or will using one
of the other replication solutions be the only way for the foreseeable
future?
Regards,
Damien
