Topic: load balancing

[dennyhalim]

is it possible to have 2/more smeserver do load balancing?

i found other article setting up backup and failover, but cant find complete load balancing.

what i mean is to have 2/more smeserver have the exact same database, same web, same mail, etc... (similar to backup mirroring)

example:
i setup a domain mysmeserver.com point to all 3 smeserver ip address:
mysmeserver.com A 1.2.3.4
mysmeserver.com A 1.2.4.5
mysmeserver.com A 1.2.6.7

so, whenever i open mysmeserver.com (which can be any of the 3 server), i can see same web, use same login, read/send same email.

anyway this can be done?

tia.

[mmccarn]

Will all three servers be at the same physical location, or will they be at separate locations?

Are you working on a load-balancing high-availability cluster, or on a distributed mail / file server of some sort?

Clustering seems to want DRDB and Heartbeat.  Here's a link to an old how-to (SME 5): http://www.opens.com.br/documentacao/HA/ (I had quite a bit of trouble finding this how-to, even though there are lots of references to it at other URLs here on contribs...)

A real-time distributed solution would be very interesting.  The closest I've seen on contribs is various rsync scripts or Michael Weinberger's AFFA.  These are primarly intended as off-site backup solutions, not server synchronization solutions.  I haven't seen anything which would provide real-time (or even batched) server synchronization...

[brentonv]

http://www.networkontrol.net/systemes/sme_server/en_high_availability_en.html

[brentonv]

http://www.networkontrol.net/systemes/sme_server/en_high_availability_en.html

[brentonv]

http://www.networkontrol.net/systemes/sme_server/en_high_availability_en.html

[brentonv]

whoops~

[dennyhalim]

3 different location.
3 different isp.

it's not quite like high availability.
but more on load balancing.

coz, when server 1.2.3.4 down and you got unlucky that dns give that ip to you, you cant access the server.

but you can access the other server directly on their ip and still access the same data, email, etc....

[mmccarn]

Do you need 'real-time' synchronization of your data, or would some sort of batched sync work (hourly, daily, whatever)?

Will you have any files on your system that require simultaneous multi-user access (such as databases)?

Will each user have a "primary" server, or do you need roaming and fail-over to be transparent?

Using SME at multiple sites, you could setup regular rsync jobs to synchronize the data folders and use something like imapsync to synchronize the email folders - but this is not a 'real time' solution...

Availl Technologies makes a "Wide Area File System" that provides real-time, multi-user distributed file and record locking services -- but requires Windows 2003 (if I remember correctly)... Cisco & others make hardware-based units that provide 'WAFS' - but the last time I checked the Cisco option cost about $20,000 for two offices...

WAFS doesn't solve your distributed email issue as far as I know...

[SoftDux]

how difficult would it be to implement heartbeat and DRDB and maybe MySQL replication / clustering into SME?

The supplied link shows an easy way to setup Heartbeat + DRDB, but it's still manual, and have to be applied to each server. It also doesn't cover MySQL

[torsten]

http://www.networkontrol.net/systemes/sme_server/en_high_availability_en.html

For anyone still interested in the subject the page is now @
http://www.networkontrol.net/content/view/126/38/