Thread: mirror content on 2 vps's

so i've got 2 vps accounts set up. at the moment the dns is a bit of a mess so we're just getting by with ip addresses, but the plan is

• host dns at dnsmadeeasy dns provider

• point to one vps to handle web traffic

• point to second vps if first one unreachable

my question to you - is there software out there that can mirror the content on both servers? ie, changes be made on server1, so they appear on server2 too?

both machines are centos linux, with mysql databases. one runs on Virtuozzo whm / cpanel, the other with lxadmin (hypervm). i have the option to have whm / cpanel on both at extra cost.

just taking a look at rsync.

Originally Posted by streetmedia

both machines are centos linux, with mysql databases. one runs on Virtuozzo whm / cpanel, the other with lxadmin (hypervm). i have the option to have whm / cpanel on both at extra cost.

just taking a look at rsync.

rsync is very good, but remember you'll always be playing catch-up with changes made to the file system. If you want to be able to switch to your standby VPS and not potentially lose a few minutes/hours (depending on how often rsync runs) of file changes, then you'll need to consider a real-time block replicator like DRBD, although as you might expect this will require assistance from your host to get it set up and certainly isn't a standard requirement, so you'll no doubt be charged appropriately for the host's time and infrastructure changes.

If you're not running a service which absolutely depends upon realtime replication, rsync is a much simpler solution.

The other potential issue is your choice of failover (DNS) - you run the risk of having people caching the old result and then not adopting the new server's IP until their local server chooses to renew the DNS record, which could be hours or days. To guarantee instant failover, you'd need to consider something like VRRP between the two VPSs which will transfer the IP locally. But then you have the problem of the edge router storing the old IP's corresponding MAC address for a while, which will also take you offline. Fun.

yeah i really just want to be able to offer my clients that bit extra comfort and be able to say that we have a failsafe in place.

i've been looking at dnsmadeeasy for a while and they get good reviews across the net.

Why not rent a VPS on a cloud? Most clouds have fault tolerance as standard.

VPS cloud? how does that work, i've never heard of it...

are there big providers supplying this? I'm happy with my current vps provider, with a great deal of trust and experience with them over the years. i wanted to try and set up the system myself (/get someone to do it) so i had control over it and wasn't relying solely on a third party.

There are a few of VPS/cloud providers here. Basically it would be a VM on redundant hardware, although if the DC goes down then you're stuck. Doing everything yourself takes much time (I've been doing mine for 12 months on/off) and isn't for the non-techy. Perhaps your current VPS provider can provide failover already? Have you checked?

Lea

ok, so after looking into all this - it seems like mirroring such a small operation is going to be inefficient compared to the amount of effort it will take.

a few folk have advised me of cloud hosting.

thing is, im happy with my WHM setup - i've been using it for years and i wish to remain with it. i thought it would be easy to set it up so it was running on two servers but apparently not...



what do you think about this:

i'm now thinking about running my vps with my main company, and setting up a static site for each of my clients websites (im a web designer) so when the first one isn;t reachable (short ttl) the static site will appear.

would i be able to acheive this using "NO CACHE" on my web pages so the pages hit fresh every time?

will the ttl method at dnsmadeeasy work ok for this idea?



i'd like to take this opportunity to thank everyone for their time in answering my queries. i really appreciate it.

wouldn't i need to take a third party dns service then? at the moment i've only got 1 vps box which handles everything. if it goes im screwed?