Re: 2-phase commit - Mailing list pgsql-hackers

From Christopher Browne
Subject Re: 2-phase commit
Date
Msg-id m31xtl4uk5.fsf@wolfe.cbbrowne.com
Whole thread Raw
In response to Re: 2-phase commit  (Andrew Sullivan <andrew@libertyrms.info>)
Responses Re: 2-phase commit  (Andrew Sullivan <andrew@libertyrms.info>)
List pgsql-hackers
The world rejoiced as t-ishii@sra.co.jp (Tatsuo Ishii) wrote:
> I'm tired of this kind of "2PC is too slow" arguments. I think
> Satoshi, the only guy who made a trial implementation of 2PC for
> PostgreSQL, has already showed that 2PC is not that slow.

I'm tired of it for a different reason, namely that there are "use
cases" where speed is not _relevant_.  The REAL problem that is taking
place is that people are talking past each other.

- Some say, "It's too slow; no point in doing it."
 The fact that it may be too slow _for them_ means they probably shouldn't use it.  I somehow doubt that there are
VastlyFaster alternatives waiting in the wings.
 

- The other problem that gets pointed out:  "2PC is inherently fragile, and prone to deadlock."
 Again, those that _need_ to use 2PC will forcibly need to address those concerns in the way they manage their
systems.
 Those that can't afford the fragility are not 'customers' for use of 2PC.  And, pointing back to the speed
controversy,it is not at all obvious that there is any other alternative for handling distributed processing that
_totallyaddresses_ the concerns about fragility.
 

Those that can't afford these costs associated with 2PC will simply
Not Use It.

Probably in much the same way that most people _aren't_ using
replication.  And most people _aren't_ using PL/R.  And most people
_aren't_ using any number of the contributed things.

If 2PC gets implemented, that simply means that there will be another
module that some will be interested in, and which many people won't
bother using.  Which shouldn't seem to be a particularly big deal.
-- 
"aa454","@","freenet.carleton.ca"
http://www.ntlug.org/~cbbrowne/
The way to a man's heart is with a broadsword.


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