MySQL Cluster

[Eric Losier]

Hi all,

This question has been asked quite a few times, but my situation is a
little bit different from what I've already read from other people.
Here I go:

I need to load-balance two servers that will be running RedHat Linux,
Apache Web Server and MySQL server, with no shared storage. I've
looked into the Linux HA project and it looks very nice. It seems I'd
be able to acheive without any complication the load-balacing of the
Apache server. However, MySQL is proving to be more challenging.

The major issue for us is that we want no single point of failure
(SPOF). Hence, both servers would be running all services (web, MySQL
and LinuxDirector). Load-balancing the "reads" from the MySQL server
is a piece of cake using MySQL's built-in master->slave replication.
However, I have no clue how to load-balance the "writes" (INSERTs,
DELETEs & UPDATEs).

One idea would be to promote the 2nd machine (original slave) to
master when the original master goes offline. However, when the latter
comes back up, it will try to reinitiate replication and all hell will
break loose !!! Also, we could be stuck with the situation where
"writes" would occur just before the master goes down, and before
those newly added (or updated or deleted) records could have been
replicated to the slave machine. We'd therefore lose some of the
"writes".

Second idea is to use the new MySQL Cluster product. I've read
somewhere that the hardware requirements can be quite high, as one
would need twice as much RAM size as the database size. IS this true?
Anyone has been using MySQL Cluster these days? Production-level
stable? Easy to configure?

Third idea is to go with Emic Networks products. The price tag
associated with this is quite high though, so this would remain as the
very last option. Unless anyone tells me it's the best product they've
ever seen ! ;) Anyone is using it?

Surely we're not the only ones stuck in this situation. Wanting a high
avaibility web/database combination is not a new concept. I can't
pretend to be *that* original ! ;)

Can anyone point me the good direction ?!

Thanks !
--
Eric Losier elosier at montrealinfo dot com
Systems Administrator
Concierge Info
http://www.montrealinfo.com

[Michael Johnson Sr.]

That's because your suppose to use a real database like Oracle.

"Eric Losier" <bi*************@yahoo.com> wrote in message
news:a4**************************@posting.google.c om...

Hi all,

This question has been asked quite a few times, but my situation is a
little bit different from what I've already read from other people.
Here I go:

I need to load-balance two servers that will be running RedHat Linux,
Apache Web Server and MySQL server, with no shared storage. I've
looked into the Linux HA project and it looks very nice. It seems I'd
be able to acheive without any complication the load-balacing of the
Apache server. However, MySQL is proving to be more challenging.

The major issue for us is that we want no single point of failure
(SPOF). Hence, both servers would be running all services (web, MySQL
and LinuxDirector). Load-balancing the "reads" from the MySQL server
is a piece of cake using MySQL's built-in master->slave replication.
However, I have no clue how to load-balance the "writes" (INSERTs,
DELETEs & UPDATEs).

One idea would be to promote the 2nd machine (original slave) to
master when the original master goes offline. However, when the latter
comes back up, it will try to reinitiate replication and all hell will
break loose !!! Also, we could be stuck with the situation where
"writes" would occur just before the master goes down, and before
those newly added (or updated or deleted) records could have been
replicated to the slave machine. We'd therefore lose some of the
"writes".

Second idea is to use the new MySQL Cluster product. I've read
somewhere that the hardware requirements can be quite high, as one
would need twice as much RAM size as the database size. IS this true?
Anyone has been using MySQL Cluster these days? Production-level
stable? Easy to configure?

Third idea is to go with Emic Networks products. The price tag
associated with this is quite high though, so this would remain as the
very last option. Unless anyone tells me it's the best product they've
ever seen ! ;) Anyone is using it?

Surely we're not the only ones stuck in this situation. Wanting a high
avaibility web/database combination is not a new concept. I can't
pretend to be *that* original ! ;)

Can anyone point me the good direction ?!

Thanks !
--
Eric Losier elosier at montrealinfo dot com
Systems Administrator
Concierge Info
http://www.montrealinfo.com