fwd: parallel PSQL ?

Forwarded from Mosix mailing-list.
Is this a crazy stuff?

Mosix isn't useful for shared memory processes (like apache and postgresql)
it simply doesn't migrate such tasks.
You can do a simple connect script that , for example , do a
round-robin connection to the different postgresql servers on the machineS.

-----------------
$dbh = connect_do_db();
---------------
first time it connects to machine1, second time to machine2 ...machineN,
than you re-start from 1, or you can poll the load of the machines and
choose the less loaded machine.

Other points: start only one machine that init the shared mem structures
(the first), not the others (is there a postgres flag to do this stuff). GFS
doesn't implement fcntl that posgres uses a bit.
The file to patch is in backend/storage/ipc/ipc.c, just add IPC_DIPC in
shmget and semget.

This is are my ideas, i've not yet done all the stuff.

If this perform ok, also other similar programs will perform ok.

bye
valter

From: "Prescott, Richard (EXP)" <richard.prescott@lmco.com>
To: mosix-list@cs.huji.ac.il
Subject: RE: PSQL, Mosix is unuseful
Date: Fri, 03 Nov 2000 14:07:22 -0500

I just though about it.

If you run DIPC + GFS + postgresql. Where the clients will connect ? I
mean. There is more than one machine answering to postgresql port! You
need to distribute the load. and that's the whole point of Mosix: one
virtual machine!

Richard

-----Original Message-----
From: valter m [SMTP:maweb@hotmail.com]
Sent: November 01, 2000 9:45 AM
To: Netmaster@streetwise.se; mosix-list@cs.huji.ac.il
Subject: Re: PSQL, Mosix is unuseful

Hello everyone,

no hope to use PostgreSQL + Mosix, because PostgreSQL uses shared

memory, as

such it's not suitable for migration.

Mosix isn't able now to give us a single system image, where a cluster

of

machine acts as a single transparent machine.

I'm trying DIPC+GFS to do this, i've patched the 2.2.17 linux kernel

with

DIPC , changed PostgreSQL sources to create distributed shared memory

and

semaphores (postgres uses only sem and shm), next steps are to try to
start-up (the changed) postgres to use this distibuted ipc and a

central

location for datafiles (GFS , NFS?, or a thing that permits a shared fs

with

flock and fcntl) , then do a simple connect script that , for example ,

do a

round-robin connection to the different postgresql servers on the

machineS.

DIPC has not a failover mechanism now.

Ideas?

bye
valter

From: Johan Sj> �holm <Netmaster@streetwise.se>
To: "Mosix List" <mosix-list@cs.huji.ac.il>
Subject: PSQL
Date: Wed, 1 Nov 2000 14:09:34 +0100

Hello everyone,

Anyone that has tryied PostgreesSQL under Mosix ? How well does it run

?

Just checking before I get going whit it;)

And I am also going to run Apache on those machines, will that work any
good ?

Whit friendly Regards

- Johan

--
To unsubscribe, send message to mosix-list-request@cs.huji.ac.il
with "unsubscribe" in the message body.

_________________________________________________________________________

Get Your Private, Free E-mail from MSN Hotmail at

http://www.hotmail.com.

Share information about yourself, create your own public profile at
http://profiles.msn.com.

--
To unsubscribe, send message to mosix-list-request@cs.huji.ac.il
with "unsubscribe" in the message body.

--
To unsubscribe, send message to mosix-list-request@cs.huji.ac.il
with "unsubscribe" in the message body.

_________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.

Share information about yourself, create your own public profile at
http://profiles.msn.com.