Mysql CLuster versus Postgress CLuster

[Piotr Kirklewski]

Hi guys
Does anyone have any experience witch PGCluster.
I'm running Mysql Cluster since some time ago and I no the pros and cons of this solution.
I just wonder if PGCluster is faster, maybe more efficient ?
Please advice
Regards
PEter

[Steven E. Protter]

Shalom,

You actually have another option, which is to use the Red Hat Cluster Suite (RHCS).

I've seen the specifications on mysql clustering technology. There are a number of options, but some people think the technology is a bit immature.

Mysql is more widely used and the development turnaround on maturity and new releases may be faster.

Postgres is very good as a databse.

Normally the needs of the application drive the decision, not the speed of the cluster.

The most tested cluster technology however among the choices may be rhcs.

SEP

[Vitaly Karasik_1]

Peter,
You should define your requerements from the cluster - is it just high-availability?
Is it just high-availability? In this case RH cluster solution may help. Is this scalability?

You should take into account, that migrating to Postgress will request serious effort from developers/QA/IT.

BTW, there is interesting presentation about MySQL and Postgress https://fossbazaar.org/content/josh-berkus-two-great-open-source-databases-comparison-2008-06-26.

[Piotr Kirklewski]

Hi
My requirements are both: high availability and scalability.
So what do you think: Is pgcluster as good solution as Mysql cluster ?
Regards
PEter

[Vitaly Karasik_1]

Unfortunately, I haven't worked with Mysql or Postgress Cluster yet.
We used Mysql replication for scalability at my previous work.

In my opinion, mysql and postgress clusters still have pre-production quality. In other words, they aren't mature enough if we compare them to Oracle RAC, for example.

So - as Steven said - there are Red Hat and other HA cluster solution which allow to build HA DB server.
And Mysql replication may help to scale out in many cases - as far as I see, many serious enterprises use it.

[Piotr Kirklewski]

IMHO MySQL Cluster is mature enough.
I'm using it since 2 years ago and it does the job beautifully - and FOR FREE :))) .
How much did you pay for Oracle solution?
Did you know that You can have the same performance for free?

My question was about postgress as I need to run some tests on both platforms to see which one is faster - and I have no experience in postgres whatsoever.

Regards

Peter

[Vitaly Karasik_1]

Interesting!
How much is your DB? I know that Mysql cluster version 5.0 puts all data&indexes into RAM. So in fact it was one of showstoppers in my previous company - our DBs were up to hundreds of GBs.

My impression about current Mysql cluster status is partually from different internet sources. But just two months ago (during "Mysql performance" course I took) I asked my lecturer (which works with many customers as consultan) about enterprise-grade mysql cluster usage. He didn't know any serious customer who runs cluster in production.


Please, no more points; I should assign points to you :-)

[Piotr Kirklewski]

Hi

Is Google serious enough ?

http://zurlocker.typepad.com/theopenforce/2005/12/googles_use_of_.html

Cluster nowadays allows for storing the data on the disk and indexes in the memory which overcomes the very well known problem of 4GB of RAM that MYSQL has. Using MYSQL with such big database as yours I would probably go into partitioning or you could split your database into current (small) and archive (big).

Regards

[Vitaly Karasik_1]

>Is Google serious enough ?
Yes, Google is serious enough for me :-|
But, IMHO, there is a serious difference between gigants like Google|Yahoo and a small companies. Google has no problem to invest many man-months into patching/customization/testing MySQL cluster and tweaking their application; and even after that it costs for them less to use mysql cluster instead of Oracle RAC, for example. But small company IMHO need just a cluster which will work - without tweaking code and w/o taking into account all this http://dev.mysql.com/doc/refman/5.0/en/mysql-cluster-limitations.html .

Don't understand me wrong - I work with Linux/FOSS since 1996 and in general I vote for free alternatives. But in many cases FOSS solutions request so many work in order to use it that I'll suggest to use more mature non-free alternatives.

>Cluster nowadays allows for storing the >data on the disk and indexes in the memory >which overcomes the very well known problem >of 4GB of RAM that MYSQL has.
well, 5.1 was released just before one month :-)
And many new features seem to be buggy - http://www.linux-magazine.com/online/news/mysql_founder_warns_5_1_not_ready

>Using MYSQL with such big database as yours >I would probably go into partitioning or >you could split your database into current >(small) and archive (big).
It was more or less our architecture - small DB for current CDRs (it was VoIP systen) and a huge datawarehouse.

[Steven E. Protter]

Shalom,

Hi Vitaly.

I had a class in May with an expert from mysql and had afterward a discussion of replication technology. He agreed with Vitaly's assessment that the technology for mysql replication is not quite mature. He expects that to be rectified in version 6 of mysql.

To be fair, google has created their own replication technology in house and may not be a representative case as their in house solution may not be widely available.

SEP