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"Clustering"
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* "Clustering"
@ 2006-11-20 19:25 Peter Eisentraut <[email protected]>
  2006-11-20 22:18 ` Re: "Clustering" Bruce Momjian <[email protected]>
  0 siblings, 1 reply; 6+ messages in thread

From: Peter Eisentraut @ 2006-11-20 19:25 UTC (permalink / raw)
  To: pgsql-docs

The heading "Multi-Master Replication Using Clustering" doesn't make 
sense to me.  Clustering is bunching more than host together to achieve 
a common goal.  Thus multimaster replication may be a way to achieve 
clustering, but clustering is not a way to achieve multimaster 
replication.  I don't actually see clustering defined in the 
documentation.  Can someone explain the categorization?

(FWIW, I think "Clustering For Parallel Query Execution" later in the 
list is an appropriate use of the term.)

-- 
Peter Eisentraut
http://developer.postgresql.org/~petere/



^ permalink  raw  reply  [nested|flat] 6+ messages in thread

* Re: "Clustering"
  2006-11-20 19:25 "Clustering" Peter Eisentraut <[email protected]>
@ 2006-11-20 22:18 ` Bruce Momjian <[email protected]>
  2006-11-21 09:42   ` Re: "Clustering" Markus Schiltknecht <[email protected]>
  0 siblings, 1 reply; 6+ messages in thread

From: Bruce Momjian @ 2006-11-20 22:18 UTC (permalink / raw)
  To: Peter Eisentraut <[email protected]>; +Cc: pgsql-docs

Peter Eisentraut wrote:
> The heading "Multi-Master Replication Using Clustering" doesn't make 
> sense to me.  Clustering is bunching more than host together to achieve 
> a common goal.  Thus multimaster replication may be a way to achieve 
> clustering, but clustering is not a way to achieve multimaster 
> replication.  I don't actually see clustering defined in the 
> documentation.  Can someone explain the categorization?

I used the term clustering to mean that the servers work closely
together.  This is not as true with the other items on the page that are
not clustering.

> (FWIW, I think "Clustering For Parallel Query Execution" later in the 
> list is an appropriate use of the term.)

Yes, I saw it as a similar issue.

-- 
  Bruce Momjian   [email protected]
  EnterpriseDB    http://www.enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +



^ permalink  raw  reply  [nested|flat] 6+ messages in thread

* Re: "Clustering"
  2006-11-20 19:25 "Clustering" Peter Eisentraut <[email protected]>
  2006-11-20 22:18 ` Re: "Clustering" Bruce Momjian <[email protected]>
@ 2006-11-21 09:42   ` Markus Schiltknecht <[email protected]>
  2006-11-21 15:50     ` Re: "Clustering" Markus Schiltknecht <[email protected]>
  2006-11-22 04:00     ` Re: "Clustering" Bruce Momjian <[email protected]>
  0 siblings, 2 replies; 6+ messages in thread

From: Markus Schiltknecht @ 2006-11-21 09:42 UTC (permalink / raw)
  To: Bruce Momjian <[email protected]>; +Cc: Peter Eisentraut <[email protected]>; pgsql-docs

Hi,

Bruce Momjian wrote:
> Peter Eisentraut wrote:
>> The heading "Multi-Master Replication Using Clustering" doesn't make 
>> sense to me.  Clustering is bunching more than host together to achieve 
>> a common goal.  Thus multimaster replication may be a way to achieve 
>> clustering, but clustering is not a way to achieve multimaster 
>> replication.  I don't actually see clustering defined in the 
>> documentation.  Can someone explain the categorization?

AFAICS, clustering seems to have no clear definition within database 
replication.

> I used the term clustering to mean that the servers work closely
> together.  This is not as true with the other items on the page that are
> not clustering.

Why not simply call in "Multi Master Replication"? That implies 
clustering, doesn't it?

Perhaps you meant a Shared Nothing Cluster by referring to clustering? 
Such a definition would make more sense.

BTW, I'm slowly beginning to accept that you don't want to mix 
"Statement-Based Replication Middleware" with "Multi Master 
Replication". ;-)

>> (FWIW, I think "Clustering For Parallel Query Execution" later in the 
>> list is an appropriate use of the term.)

That reminds me of the requirement of having Multi Master Replication in 
place to do Parallel Query Execution. Sync Multi Master Replication 
being better, while Async Multi Master Replication obviously leads to 
inconsistent responses, when queried in parallel. That may be acceptable 
in certain situations.

Again, IMHO, "Parallel Query Execution" says everything. The word 
'Clustering' does not help, because it's not defined nor commonly used 
in any helpful way (probably besides marketing).

Regards

Markus



^ permalink  raw  reply  [nested|flat] 6+ messages in thread

* Re: "Clustering"
  2006-11-20 19:25 "Clustering" Peter Eisentraut <[email protected]>
  2006-11-20 22:18 ` Re: "Clustering" Bruce Momjian <[email protected]>
  2006-11-21 09:42   ` Re: "Clustering" Markus Schiltknecht <[email protected]>
@ 2006-11-21 15:50     ` Markus Schiltknecht <[email protected]>
  2006-11-22 04:04       ` Re: "Clustering" Bruce Momjian <[email protected]>
  1 sibling, 1 reply; 6+ messages in thread

From: Markus Schiltknecht @ 2006-11-21 15:50 UTC (permalink / raw)
  To: ; +Cc: Bruce Momjian <[email protected]>; Peter Eisentraut <[email protected]>; pgsql-docs

Hi,

I wrote:
> That reminds me of the requirement of having Multi Master Replication in 
> place to do Parallel Query Execution. Sync Multi Master Replication 
> being better, while Async Multi Master Replication obviously leads to 
> inconsistent responses, when queried in parallel. That may be acceptable 
> in certain situations.

Oops, during rereading "Clustering For Parallel Query Execution", I've 
noticed that you mention Data Partitioning as one possible way to do 
Parallel Query Execution. Thus Multi Master Replication obviously is not 
a requirement, but just another way to allow for Parallel Query 
Execution. Mentioning that as well would probably be good.

IMHO, the advice to use multiple, independent databases to do parallel 
query execution sounds a little meager. Of course it's also parallel 
query execution, but it's not what most people suspect to find under 
that section, I would guess.

Regards

Markus




^ permalink  raw  reply  [nested|flat] 6+ messages in thread

* Re: "Clustering"
  2006-11-20 19:25 "Clustering" Peter Eisentraut <[email protected]>
  2006-11-20 22:18 ` Re: "Clustering" Bruce Momjian <[email protected]>
  2006-11-21 09:42   ` Re: "Clustering" Markus Schiltknecht <[email protected]>
  2006-11-21 15:50     ` Re: "Clustering" Markus Schiltknecht <[email protected]>
@ 2006-11-22 04:04       ` Bruce Momjian <[email protected]>
  0 siblings, 0 replies; 6+ messages in thread

From: Bruce Momjian @ 2006-11-22 04:04 UTC (permalink / raw)
  To: Markus Schiltknecht <[email protected]>; +Cc: Peter Eisentraut <[email protected]>; pgsql-docs

Markus Schiltknecht wrote:
> Hi,
> 
> I wrote:
> > That reminds me of the requirement of having Multi Master Replication in 
> > place to do Parallel Query Execution. Sync Multi Master Replication 
> > being better, while Async Multi Master Replication obviously leads to 
> > inconsistent responses, when queried in parallel. That may be acceptable 
> > in certain situations.
> 
> Oops, during rereading "Clustering For Parallel Query Execution", I've 
> noticed that you mention Data Partitioning as one possible way to do 
> Parallel Query Execution. Thus Multi Master Replication obviously is not 
> a requirement, but just another way to allow for Parallel Query 
> Execution. Mentioning that as well would probably be good.

Uh, multi-master replication allows for load balancing, but it doesn't
help a single query to run any faster.  Think of having only one query
running on the cluster.  Parallel execution allows a single query to use
more than one computer, right?

> IMHO, the advice to use multiple, independent databases to do parallel 
> query execution sounds a little meager. Of course it's also parallel 
> query execution, but it's not what most people suspect to find under 
> that section, I would guess.

Uh, this confuses me.  What is missing?  You split tables across
multiple servers.

-- 
  Bruce Momjian   [email protected]
  EnterpriseDB    http://www.enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +




^ permalink  raw  reply  [nested|flat] 6+ messages in thread

* Re: "Clustering"
  2006-11-20 19:25 "Clustering" Peter Eisentraut <[email protected]>
  2006-11-20 22:18 ` Re: "Clustering" Bruce Momjian <[email protected]>
  2006-11-21 09:42   ` Re: "Clustering" Markus Schiltknecht <[email protected]>
@ 2006-11-22 04:00     ` Bruce Momjian <[email protected]>
  1 sibling, 0 replies; 6+ messages in thread

From: Bruce Momjian @ 2006-11-22 04:00 UTC (permalink / raw)
  To: Markus Schiltknecht <[email protected]>; +Cc: Peter Eisentraut <[email protected]>; pgsql-docs

Markus Schiltknecht wrote:
> Hi,
> 
> Bruce Momjian wrote:
> > Peter Eisentraut wrote:
> >> The heading "Multi-Master Replication Using Clustering" doesn't make 
> >> sense to me.  Clustering is bunching more than host together to achieve 
> >> a common goal.  Thus multimaster replication may be a way to achieve 
> >> clustering, but clustering is not a way to achieve multimaster 
> >> replication.  I don't actually see clustering defined in the 
> >> documentation.  Can someone explain the categorization?
> 
> AFAICS, clustering seems to have no clear definition within database 
> replication.

OK, new title is "Synchonous Multi-Master Replication", and the next
heading is "Asynchronous Multi-Master Replication".

> 
> > I used the term clustering to mean that the servers work closely
> > together.  This is not as true with the other items on the page that are
> > not clustering.
> 
> Why not simply call in "Multi Master Replication"? That implies 
> clustering, doesn't it?

Well, not really because of the async multi-master that is the next
item.

> 
> Perhaps you meant a Shared Nothing Cluster by referring to clustering? 
> Such a definition would make more sense.
> 
> BTW, I'm slowly beginning to accept that you don't want to mix 
> "Statement-Based Replication Middleware" with "Multi Master 
> Replication". ;-)

OK, are they mixed now?

> >> (FWIW, I think "Clustering For Parallel Query Execution" later in the 
> >> list is an appropriate use of the term.)
> 
> That reminds me of the requirement of having Multi Master Replication in 
> place to do Parallel Query Execution. Sync Multi Master Replication 
> being better, while Async Multi Master Replication obviously leads to 
> inconsistent responses, when queried in parallel. That may be acceptable 
> in certain situations.

OK, I think we have that covered now.

> Again, IMHO, "Parallel Query Execution" says everything. The word 
> 'Clustering' does not help, because it's not defined nor commonly used 
> in any helpful way (probably besides marketing).

OK, new title is Multi-Server Parallel Query Execution.  If I have just
"Parallel Query Execution", it could be multi-process parallel
query execution.

-- 
  Bruce Momjian   [email protected]
  EnterpriseDB    http://www.enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +



^ permalink  raw  reply  [nested|flat] 6+ messages in thread


end of thread, other threads:[~2006-11-22 04:04 UTC | newest]

Thread overview: 6+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2006-11-20 19:25 "Clustering" Peter Eisentraut <[email protected]>
2006-11-20 22:18 ` Bruce Momjian <[email protected]>
2006-11-21 09:42   ` Markus Schiltknecht <[email protected]>
2006-11-21 15:50     ` Markus Schiltknecht <[email protected]>
2006-11-22 04:04       ` Bruce Momjian <[email protected]>
2006-11-22 04:00     ` Bruce Momjian <[email protected]>

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