I have lately been getting into setting up custom high availability configurations, I am wondering if it would be worth while to set up cpanel in a high availability environment. I began testing something like this, but ran into issues with figuring out which files to sync between machines, I know the home directory as well as /usr/local/apache would be 2 that are synced but I am not sure on what else. I already have it so when a database or database user is created they are replicated to mysql on the other machine.

Cpanel and clustering are not good friends (but some hosts have achieve it with hard work, trial and error and of course with neverending bugs I suppose). One problem is if you have a central db server to be used by different cpanel web servers, make sure the users have different usernames.

Other control panels can support clustering and load balancers easily like H-Sphere, InterWorx etc.

I feel that I'm really close to getting it working with cpanel, but h-sphere or interworx may be a better option I will take a look at them, thanks for the advice tonyFF

I don't think it makes much sense business wise.
*Good* cpanel hosts will get more than 99.95% uptime - the remaining seconds/month do not really matter imho - and won't justify the higher prices.

Having said that - we 'cluster out' a few functions.

I don't think it makes much sense business wise.
*Good* cpanel hosts will get more than 99.95% uptime - the remaining seconds/month do not really matter imho - and won't justify the higher prices.

Having said that - we 'cluster out' a few functions.

It depends on who you're talking about. Seconds or minutes could mean thousands+ to certain businesses.

I don't think it makes much sense business wise.
*Good* cpanel hosts will get more than 99.95% uptime - the remaining seconds/month do not really matter imho - and won't justify the higher prices.

Having said that - we 'cluster out' a few functions.

For the most, part, you're right. If there was ever a catastrophic server failure of any kind however (motherboard chipset fried, 2 disks fail simultaneously in the RAID5 setup...) then you'd be looking at more than an hour of downtime sorting out spares and/or moving the data.

However, what high-availability hosting does do (or should do) is take out every possible Single Point of Failure in the system. So that if there is a catastrophic failure of any kind, it should result in zero or extremely minimal downtime (i.e. seconds) whilst the system fails over.

cPanel is generally not a good idea to hack into a cluster because unless you want to keep it running an old version indefinitely, it's more than likely that their automatic updates will break something somewhere down the line.

I agree, maybe I need to find a more basic panel to use in a linux-ha environment. Any suggestions?

It depends on who you're talking about. Seconds or minutes could mean thousands+ to certain businesses.

Then shared hosting is not an option for these sites :)

The OP is looking to start a HA shared hosting service.

here is how you can do a High Availability in easy way
Node 1 XEN Server
Node 2 XEN Server
Shared Fiber Channel Storage

On a top install CentOS+cPanel and here is your High Availability cPanel cluster.

Also XEN is free in now days.

ydonchenko, xen is always a possibility, it is a lot easier to create HA systems with xen nodes. I am starting to think, I may want to set each client up with their own custom ha nodes instead of doing the shared set up.

You can also have HA with 3tera os - LayeredTech (theGridLayer) offers some packages with Cpanel. No need to re-invent the wheel :)

AFAIK, the grid layer looks to be a HA virtualization platform... so you can install a VM with cPanel if you want, but it won't have load-balancing or other cool features.

cPanel is hardly "the wheel" in any case. :p

tonyff do you have any personal experience using this service?

dazmanultra, not looking to load balance just to offer ha services with cpanel, the load balancing would be for the more serious, non cpanel clients

dazmanultra, not looking to load balance just to offer ha services with cpanel, the load balancing would be for the more serious, non cpanel clients

Perhaps, but as a supposed High Availability solution, you will need to have a plan in place if a site hosted in a virtual environment gets extremely busy (e.g featured on the news, for example) and threatens to overload your VM.

You can scale most virtual machines up on the fly - but they tend to only scale up to the equivalent of a normal server.

Daz,

good point, the only solution i saw that scaled past that was offered at vps.net

tonyff do you have any personal experience using this service?

No, I do not have any experience with LT, but it definetely seems interesting. Of course, there are other providers using Applogic's 3tera.


Perhaps, but as a supposed High Availability solution, you will need to have a plan in place if a site hosted in a virtual environment gets extremely busy (e.g featured on the news, for example) and threatens to overload your VM.

You can scale most virtual machines up on the fly - but they tend to only scale up to the equivalent of a normal server.

As I remember, you can scale a VM up to many physical machines. You can do "anything" with the 3tera editor. You can have load balancers, centralised storage, mysql clusters etc. even in different datacenters. The limitation here is what Cpanel can do!

A sales request to any provider offering this platform can solve these question.

But even the pricing of a TheGridLayer VPS, with Cpanel and HA built-in (auto failover) is very very attractive. You can start small and while you have more customers you can scale the VPS.

A similar offering is also from UK2.net brand (vps.net) - you can scale a vps instantly (and not wait the provider billing > support queue) and it has failover. I do not know about their technology but it seems interesting :)

As I remember, you can scale a VM up to many physical machines. You can do "anything" with the 3tera editor. You can have load balancers, centralised storage, mysql clusters etc. even in different datacenters. The limitation here is what Cpanel can do!

Well yes, you can provision any number of VMs in any role you like. As you say, cPanel is the weak link here. :)

tonyff, I have been looking at vps.net, it looks quite promising, basically I am curious if I install cpanel on one node and scale up to two, do I have to set up loadbalencing or does it auto cluster etc. I sent them an email but have recieved no response yet.

With vps.net you can scale up to 1 node (as I understand it) - but better wait the response from their sales and do inform us please!

maybe i will just sign up for it and see how it works :)

Good idea, it's actually very cheap (10$).

tonyff, I have been looking at vps.net, it looks quite promising, basically I am curious if I install cpanel on one node and scale up to two, do I have to set up loadbalencing or does it auto cluster etc. I sent them an email but have recieved no response yet.

If you want cpanel running on a VPS.NET cloud server, you just sign up, choose the Centos cpanel image (gives you 30 days free cpanel trial) and go for it.

You can scale it up and down as you need to in order to match the resources needed by your websites/clients.

Everything on the VPS.net is clustered, so the number of single points of failures are very limited.

We do have a HAproxy image available, but as mentioned earlier - cPanel is not that keen on running of traditional LB's...

Let me know if you have other questions - post here, to me or on our vps.net forums

:)
D

thanks eming, so what happens if i had cpanel installed and upgraded to the 5 node cluster does that mean my cpanel installation recieves 400mhz * 5 cpu power? or do I need to do additional configuration on my end?

thanks eming, so what happens if i had cpanel installed and upgraded to the 5 node cluster does that mean my cpanel installation recieves 400mhz * 5 cpu power? or do I need to do additional configuration on my end?

No, thats it really :)

If you upgrade your server from 2 nodes (2x400mhz) to 5 nodes (5x400mhz) your server would simply be upgraded from 800mhz to 2000mhz.
The upgrade is real-time as in 'instant', and nothing else is needed on your side. You can downgrade anytime the same way...

:)
D

sounds quite nice :)