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Anything "time" critical on www.postgresql.org VM?
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* Anything "time" critical on www.postgresql.org VM?
@ 2004-09-26 19:30  Marc G. Fournier <[email protected]>
  0 siblings, 1 reply; 9+ messages in thread

From: Marc G. Fournier @ 2004-09-26 19:30 UTC (permalink / raw)
  To: pgsql-www


I'd like to setup hot failover for that VM, so that if the server it is 
running on goes down, it will auto-come back up on a second server.  So 
far, the finest I can get the replication granularity is 15 minutes, so 
there is the potential of 15 minutes worth of 'data' to be lost on a crash 
...

As I believe that most (if not all?) of the stuff on that VM is pretty 
static as far as files, and there is no email over there, I can't think of 
any reason *not* to do this for that VM ... but, I wanted to check here to 
see if anyone knows of a reason that the potential lose of '15 minutes' 
worth of data is a bad thing?

If not, I'll get that setup ...

I don't believe that any of the other VMs can have this setup yet, until I 
can get the 'gap' reduced between replicas, since they are all dealing 
with CVS in some form or another, or email ...


----
Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email: [email protected]           Yahoo!: yscrappy              ICQ: 7615664



^ permalink  raw  reply  [nested|flat] 9+ messages in thread

* Re: Anything "time" critical on www.postgresql.org VM?
@ 2004-09-26 22:48  Justin Clift <[email protected]>
  parent: Marc G. Fournier <[email protected]>
  0 siblings, 1 reply; 9+ messages in thread

From: Justin Clift @ 2004-09-26 22:48 UTC (permalink / raw)
  To: Marc G. Fournier <[email protected]>; +Cc: pgsql-www

Marc G. Fournier wrote:
> 
> I'd like to setup hot failover for that VM, so that if the server it is 
> running on goes down, it will auto-come back up on a second server.  So 
> far, the finest I can get the replication granularity is 15 minutes, so 
> there is the potential of 15 minutes worth of 'data' to be lost on a 
> crash ...

Hi Marc,

What kind of replication is being used?

:)

Regards and best wishes,

Justin Clift



^ permalink  raw  reply  [nested|flat] 9+ messages in thread

* Re: Anything "time" critical on www.postgresql.org VM?
@ 2004-09-26 23:44  Marc G. Fournier <[email protected]>
  parent: Justin Clift <[email protected]>
  0 siblings, 1 reply; 9+ messages in thread

From: Marc G. Fournier @ 2004-09-26 23:44 UTC (permalink / raw)
  To: Justin Clift <[email protected]>; +Cc: Marc G. Fournier <[email protected]>; pgsql-www

On Mon, 27 Sep 2004, Justin Clift wrote:

> Marc G. Fournier wrote:
>> 
>> I'd like to setup hot failover for that VM, so that if the server it is 
>> running on goes down, it will auto-come back up on a second server.  So 
>> far, the finest I can get the replication granularity is 15 minutes, so 
>> there is the potential of 15 minutes worth of 'data' to be lost on a crash 
>> ...
>
> Hi Marc,
>
> What kind of replication is being used?

rsync right now, unless you know of something better that works under 
FreeBSD?  I'd love to find something more 'real time', but haven't been 
able to find anything that could be run on an existing server ...


----
Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email: [email protected]           Yahoo!: yscrappy              ICQ: 7615664



^ permalink  raw  reply  [nested|flat] 9+ messages in thread

* Re: Anything "time" critical on www.postgresql.org VM?
@ 2004-09-27 07:53  Dave Page <[email protected]>
  0 siblings, 0 replies; 9+ messages in thread

From: Dave Page @ 2004-09-27 07:53 UTC (permalink / raw)
  To: Marc G. Fournier <[email protected]>; pgsql-www

 

> -----Original Message-----
> From: [email protected] 
> [mailto:[email protected]] On Behalf Of Marc G. Fournier
> Sent: 26 September 2004 20:30
> To: [email protected]
> Subject: [pgsql-www] Anything "time" critical on 
> www.postgresql.org VM?
> 
> 
> I'd like to setup hot failover for that VM, so that if the 
> server it is running on goes down, it will auto-come back up 
> on a second server.  So far, the finest I can get the 
> replication granularity is 15 minutes, so there is the 
> potential of 15 minutes worth of 'data' to be lost on a crash ...
> 
> As I believe that most (if not all?) of the stuff on that VM 
> is pretty static as far as files, and there is no email over 
> there, I can't think of any reason *not* to do this for that 
> VM ... but, I wanted to check here to see if anyone knows of 
> a reason that the potential lose of '15 minutes' 
> worth of data is a bad thing?
> 
> If not, I'll get that setup ...
> 
> I don't believe that any of the other VMs can have this setup 
> yet, until I can get the 'gap' reduced between replicas, 
> since they are all dealing with CVS in some form or another, 
> or email ...

There's nothing time critical on there as far as the 'official' services
go. Dunno if any of the users have any other tasks running that might
be, but I doubt it.

I say go for it!

Regards, Dave




^ permalink  raw  reply  [nested|flat] 9+ messages in thread

* Re: Anything "time" critical on www.postgresql.org VM?
@ 2004-09-27 08:06  Justin Clift <[email protected]>
  parent: Marc G. Fournier <[email protected]>
  0 siblings, 0 replies; 9+ messages in thread

From: Justin Clift @ 2004-09-27 08:06 UTC (permalink / raw)
  To: Marc G. Fournier <[email protected]>; +Cc: pgsql-www

Marc G. Fournier wrote:
> On Mon, 27 Sep 2004, Justin Clift wrote:
<snip>
>> Hi Marc,
>>
>> What kind of replication is being used?
> 
> rsync right now, unless you know of something better that works under 
> FreeBSD?  I'd love to find something more 'real time', but haven't been 
> able to find anything that could be run on an existing server ...

Oh well, it sounds like it'll have to do.

They use rsync here too for file based syncronisation.  It get's bitched 
and moaned about, but "does the job".

Regards and best wishes,

Justin Clift




^ permalink  raw  reply  [nested|flat] 9+ messages in thread

* Re: Anything "time" critical on www.postgresql.org VM?
@ 2004-09-27 08:28  John Hansen <[email protected]>
  0 siblings, 1 reply; 9+ messages in thread

From: John Hansen @ 2004-09-27 08:28 UTC (permalink / raw)
  To: Justin Clift <[email protected]>; Marc G. Fournier <[email protected]>; +Cc: pgsql-www

> rsync right now, unless you know of something better that works under 
> FreeBSD?  I'd love to find something more 'real time', but haven't 
> been able to find anything that could be run on an existing server ...

Doesn't FreeBSD have support for OpenAFS and/or CODA?

... John



^ permalink  raw  reply  [nested|flat] 9+ messages in thread

* Re: Anything "time" critical on www.postgresql.org VM?
@ 2004-09-27 14:16  Marc G. Fournier <[email protected]>
  parent: John Hansen <[email protected]>
  0 siblings, 1 reply; 9+ messages in thread

From: Marc G. Fournier @ 2004-09-27 14:16 UTC (permalink / raw)
  To: John Hansen <[email protected]>; +Cc: Justin Clift <[email protected]>; Marc G. Fournier <[email protected]>; pgsql-www

On Mon, 27 Sep 2004, John Hansen wrote:

>> rsync right now, unless you know of something better that works under
>> FreeBSD?  I'd love to find something more 'real time', but haven't
>> been able to find anything that could be run on an existing server ...
>
> Doesn't FreeBSD have support for OpenAFS and/or CODA?

k, I looked at Coda, and liked the concept ... but, it looks like 
something that, to implement, I'll have to setup before I put anything on 
the server, I can easily move a server to it ... and, from everything I 
read, I'm not 100% certain that it would even do what I wanted ... each 
time I thought I found the answer, reading a bit further seemed to negate 
it :(

The thing is, its really simple ... two servers, each with a large file 
system (/vm) ... on that file system are subdirectories by company_id and 
then domain under that ... a domain is active only on one server, so the 
only thing being written to /vm/id/domain would be on one server, but 
/vm/otherid/domain (or even /vm/id/otherdomain) ... so I want changes to 
/vm/id/domain from ServerA 'replicated' to ServerB, and /vm/id/otherdomain 
from ServerB to ServerA (which is what I'm doing with rsync) ...

I had looked at unison also, but it looked to have similar 'lag' 
restrictions as rsync does, and some limitations as to the kinds of files 
it could send back and forth ...

Using rsync, and some mods that Andrea (oicu) helped me with to 
parrallelize it, I've been able to get granularity down to 5 minutes 
instead of 15, at least based on 4 VMs right now taking ~150 seconds total 
to keep in sync ...



----
Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email: [email protected]           Yahoo!: yscrappy              ICQ: 7615664



^ permalink  raw  reply  [nested|flat] 9+ messages in thread

* Re: Anything "time" critical on www.postgresql.org VM?
@ 2004-09-27 15:51  Justin Clift <[email protected]>
  parent: Marc G. Fournier <[email protected]>
  0 siblings, 1 reply; 9+ messages in thread

From: Justin Clift @ 2004-09-27 15:51 UTC (permalink / raw)
  To: Marc G. Fournier <[email protected]>; +Cc: John Hansen <[email protected]>; pgsql-www

Marc G. Fournier wrote:
<snip>
> Using rsync, and some mods that Andrea (oicu) helped me with to 
> parrallelize it, I've been able to get granularity down to 5 minutes 
> instead of 15, at least based on 4 VMs right now taking ~150 seconds 
> total to keep in sync ...

Hmmm... I wonder if it'd be possible to use that PG backed filesystem 
someone created a while ago, then use PG replication (Slony, etc) to 
just replicate that?

:)

(Ok, prob not feasible, but it's an interesting thought)

Regards and best wishes,

Justin Clift




^ permalink  raw  reply  [nested|flat] 9+ messages in thread

* Re: Anything "time" critical on www.postgresql.org VM?
@ 2004-09-27 18:10  Marc G. Fournier <[email protected]>
  parent: Justin Clift <[email protected]>
  0 siblings, 0 replies; 9+ messages in thread

From: Marc G. Fournier @ 2004-09-27 18:10 UTC (permalink / raw)
  To: Justin Clift <[email protected]>; +Cc: John Hansen <[email protected]>; pgsql-www

On Tue, 28 Sep 2004, Justin Clift wrote:

> Marc G. Fournier wrote:
> <snip>
>> Using rsync, and some mods that Andrea (oicu) helped me with to 
>> parrallelize it, I've been able to get granularity down to 5 minutes 
>> instead of 15, at least based on 4 VMs right now taking ~150 seconds total 
>> to keep in sync ...
>
> Hmmm... I wonder if it'd be possible to use that PG backed filesystem someone 
> created a while ago, then use PG replication (Slony, etc) to just replicate 
> that?

I'd thought about that, but for the kind of loads I put onto it, I don't 
know it would stand up ... it would definitely make failover alot easier, 
similar to doing NFS ...

----
Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email: [email protected]           Yahoo!: yscrappy              ICQ: 7615664




^ permalink  raw  reply  [nested|flat] 9+ messages in thread


end of thread, other threads:[~2004-09-27 18:10 UTC | newest]

Thread overview: 9+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2004-09-26 19:30 Anything "time" critical on www.postgresql.org VM? Marc G. Fournier <[email protected]>
2004-09-26 22:48 ` Justin Clift <[email protected]>
2004-09-26 23:44   ` Marc G. Fournier <[email protected]>
2004-09-27 08:06     ` Justin Clift <[email protected]>
2004-09-27 07:53 Re: Anything "time" critical on www.postgresql.org VM? Dave Page <[email protected]>
2004-09-27 08:28 Re: Anything "time" critical on www.postgresql.org VM? John Hansen <[email protected]>
2004-09-27 14:16 ` Marc G. Fournier <[email protected]>
2004-09-27 15:51   ` Justin Clift <[email protected]>
2004-09-27 18:10     ` Marc G. Fournier <[email protected]>

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