Thread: PostgreSQL in Cluster
Hi everyone,
Anyone have PostgreSQL running on a cluster?
I'm trying to run on a OpenMosix 2-machine cluster but the processes are not migrating.
All the load is concentrating in one machine.
And, how can I have fail over?
Thank you,
Luiz
On Fri, 27 Feb 2004, Luiz Guilherme Freitas de Paula wrote: > Hi everyone, > > Anyone have PostgreSQL running on a cluster? > I'm trying to run on a OpenMosix 2-machine cluster but the processes are not migrating. > All the load is concentrating in one machine. > And, how can I have fail over? so far, everyone who's tested postgresql on openmosix has found it to be quite slow. IT would appear the shared memory is the deal breaker there.
On Friday 27 February 2004 18:31, Luiz Guilherme Freitas de Paula wrote: > Hi everyone, > > Anyone have PostgreSQL running on a cluster? > I'm trying to run on a OpenMosix 2-machine cluster but the processes are > not migrating. All the load is concentrating in one machine. I don't think openmosix allows shared memory to migrate. Since PG uses shared memory to communicate between backends, this will cause you problems. > And, how can I have fail over? More information? -- Richard Huxton Archonet Ltd
Is there any way to use PostgreSQL in a cluster configuration or have redundancy? How can I have my DB to not stop on hardware failure? Thank you, Luiz > On Friday 27 February 2004 18:31, Luiz Guilherme Freitas de Paula wrote: > > Hi everyone, > > > > Anyone have PostgreSQL running on a cluster? > > I'm trying to run on a OpenMosix 2-machine cluster but the processes are > > not migrating. All the load is concentrating in one machine. > > I don't think openmosix allows shared memory to migrate. Since PG uses shared > memory to communicate between backends, this will cause you problems. > > > And, how can I have fail over? > > More information? > > -- > Richard Huxton > Archonet Ltd > > ---------------------------(end of broadcast)--------------------------- > TIP 3: if posting/reading through Usenet, please send an appropriate > subscribe-nomail command to majordomo@postgresql.org so that your > message can get through to the mailing list cleanly >
On Friday 27 February 2004 20:13, Luiz Guilherme Freitas de Paula wrote: > Is there any way to use PostgreSQL in a cluster configuration or have > redundancy? Well, you don't say much about your hardware, usage patterns etc. but you might want look at the various replication options currently available. There's one in the source distribution: contrib/dbmirror. Or perhaps erserver/rservimp on gborg.postgresql.org > How can I have my DB to not stop on hardware failure? I don't know of anyone doing instant fail-over to a secondary machine. You might want to consider the following: 1. External, shared RAID drives (note that you *MUST NOT* run two versions of PG against the same files) 2. Duplicate machines with replication and one of the "heartbeat+failover" options (free or commercial) 3. Commercial high-availability hardware (I know - too expensive) Can't say much more without knowing what you want. Whatever path you decide to take, do a proper risk assessment first and allow time to understand the systems involved and too proper testing. -- Richard Huxton Archonet Ltd
> Is there any way to use PostgreSQL in a cluster configuration or have > redundancy? > How can I have my DB to not stop on hardware failure? You can have a fail-over cluster by having an external disk array connected to two machines, where machine B is activated, mounts the disks, and switches off power from machine A if it fails. Jon > > Thank you, > > Luiz > > > On Friday 27 February 2004 18:31, Luiz Guilherme Freitas de Paula wrote: > > > Hi everyone, > > > > > > Anyone have PostgreSQL running on a cluster? > > > I'm trying to run on a OpenMosix 2-machine cluster but the processes are > > > not migrating. All the load is concentrating in one machine. > > > > I don't think openmosix allows shared memory to migrate. Since PG uses > shared > > memory to communicate between backends, this will cause you problems. > > > > > And, how can I have fail over? > > > > More information? > > > > -- > > Richard Huxton > > Archonet Ltd > > > > ---------------------------(end of broadcast)--------------------------- > > TIP 3: if posting/reading through Usenet, please send an appropriate > > subscribe-nomail command to majordomo@postgresql.org so that your > > message can get through to the mailing list cleanly > > > > > ---------------------------(end of broadcast)--------------------------- > TIP 6: Have you searched our list archives? > > http://archives.postgresql.org >
-----Mensagem original-----
De: pgsql-general-owner@postgresql.org
[mailto:pgsql-general-owner@postgresql.org] Em nome de Luiz Guilherme
Freitas de Paula
Enviada em: sexta-feira, 27 de fevereiro de 2004 17:14
Para: Richard Huxton; pgsql-general@postgresql.org
Assunto: Re: [GENERAL] PostgreSQL in Cluster
Is there any way to use PostgreSQL in a cluster configuration or have
redundancy?
How can I have my DB to not stop on hardware failure?
Thank you,
Luiz
> On Friday 27 February 2004 18:31, Luiz Guilherme Freitas de Paula
wrote:
> > Hi everyone,
> >
> > Anyone have PostgreSQL running on a cluster?
> > I'm trying to run on a OpenMosix 2-machine cluster but the processes
are
> > not migrating. All the load is concentrating in one machine.
>
> I don't think openmosix allows shared memory to migrate. Since PG uses
shared
> memory to communicate between backends, this will cause you problems.
>
> > And, how can I have fail over?
>
> More information?
>
> --
> Richard Huxton
> Archonet Ltd
>
> ---------------------------(end of
broadcast)---------------------------
> TIP 3: if posting/reading through Usenet, please send an appropriate
> subscribe-nomail command to majordomo@postgresql.org so that
your
> message can get through to the mailing list cleanly
>
---------------------------(end of broadcast)---------------------------
TIP 6: Have you searched our list archives?
http://archives.postgresql.org
> Hi everyone, Hello! > > Anyone have PostgreSQL running on a cluster? Yes. Someone :) Me :) > I'm trying to run on a OpenMosix 2-machine cluster but the processes are > not migrating. The solution you are looking for is depending on what you want to get srom it. I mean even oracle cluster solution do not allow to migrate updates if while update is going on the hardware fail happend. It migrate to a second node and all selects are starting from the beginning and update and inserts are canselled (as far as i know). So to find a solution you should know: 1. How much time your database could be unavailable (one second per year or one hour per day) 2. Does your application could recoonect to a database if the problem arise. 3. Does your application is cappable to check data consistancy (after insert, update whatever if fail happend) ............ 1001. As for me i answerred all that questions and have the following configuration: 1. Two Intel SRKA4 machines with RAID1 for OS and RAID5 for databasee (i know that RAID5 is too slow but for me it is just a solution) 2. Bouth computers connected to different power feeders via different UPSs. 3. I have 3 dedicated Gigabit ethernet connections established between computers for data mirroring and two more for data access from the network. 4. Red Hat Linux8 installed it is a pitty thing because i'm using FreeBSD on all other servers but DRBD is available only for linux. 5. All disks being mirrored over a network using DRBD software. All database drives are configured to write data to remote node first (Protocol C). 6. Hardware being monitored with heartbeat software that is configured to send beats each second and if 2 heartbeats are missing it consider it is as hardware mulfunction 7. Postgress migrating from one computer to another in 5 seconds. 8. There is a special daemon that controlls data consistancy. Best regards, Anton > All the load is concentrating in one machine. > And, how can I have fail over? > > Thank you, > > Luiz