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Number of domains hosted

CosminM

New Pleskian
Hello,

Is there a way to approximate the maximum number of domains that I can host on a single server? Of course, depending on hardware configuration: let's say dual xeon quad core , 16 gb ram
I need some opinions.
Thank you!
 
Thanks for replying. So I suppose there won't be a problem at all hosting about 1000 active domains on a single dual quad core xeon+16gb ram server. Most of the domains require about 20-40 gb traffic/month.
Thank you!
 
Thanks for replying. So I suppose there won't be a problem at all hosting about 1000 active domains on a single dual quad core xeon+16gb ram server. Most of the domains require about 20-40 gb traffic/month.
Thank you!

I hope you thoroughly enjoy getting 1,000+ sites on a server with Plesk in a high performance environment. We do, and we've had to rip the internals of Plesk apart to get the performance we need, and deal with some ridiculous bugs/issues along the way.

Some notes:
  • Specs of our servers are around Dual Quad Xeons, 24+ GB RAM, RAID 10 SAS disks.
  • Replace apache-mpm-prefork with apache-mpm-worker if you're using PHP as FastCGI (Did this through some Debian package management, tricking Plesk to think that prefork is still installed)
  • PHP as FastCGI if you're a PHP shop. Goes with the above, and works much nicer. If you need PHP settings such as open base dir, change the FCGIWrapper to point to a custom PHP call (/usr/bin/php5-cgi -c /example.com.ini) in vhost.conf and write these out with event hooks.
  • You're more than likely to get file descriptor errors because of the error logs being opened for each site. You can increase your number of file descriptors/recompile Apache if you want but that just seems silly. We ended up modifying the Apache init script to go through any vhosts that have the ErrorLog line and remove it, falling back to a shared error log. (our customers don't need the error logs)
  • Don't rely on Plesk for backups - they're slow and clunky, especially if you're backing up heaps of data. Find something that does block level differentials.
  • Domain management (adding, removing, renaming) etc in Plesk becomes ridiculously slow. We ended up writing our own versions of these that interface with the psa database and commands.
  • With the above, we replaced several Plesk binaries with /bin/true (such as the webmailmng) as we didn't have a need for them and we found when creating a new site, Apache would restart/reload several times which caused connectivity issues for customers.
  • Enable piped logs. This should go without saying.
  • The Plesk 9.3 option to put another web server in front is nice, but was built completely wrong. Implementing it means you need to mess with event hooks and several other things. We wrapped out own which means our front end nginx servers don't need a reload at all, they simply proxy upstream.
  • Tune the **** out of Apache, and MySQL - should also go without saying.
  • Enjoy SLOW Plesk upgrades. Our migration to 9.3 takes over an hour on our equipment, because Plesk rebuilds all mail and all DNS zones at least 3 times for some reason. Plan well in advance, and as soon as Plesk shuts down Apache, /opt/psa/admin/sbin/websrvmng -a -v to rebuild configs and start it again whilst the upgrade finishes - no harm in doing so.

If I think of anything else I'll put through another reply, and consider writing some of this up with howto's in blog posts or something.
 
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