Something that has bugged me for years and years and surprises me something does not easily exist, is say a server goes down, for example maintenance whilst the Linode is upgraded, any domains will just have a Page Not Found because there is no server to respond to the request. I understand this but what I dont understand is why hosting providers dont have something in place to show some standard maintenance message when a server is down. Like some switch I can redirect all IPs on a server to somewhere else to intercept any requests and show a message. It is soooo much better to show a simple down for maintenance message than a page not found.

I rarely perform server maintenance because of this. I have to inform all customers way in advance then stick to it, then make sure its done as fast as possible, its awful. If a simple maintenance message was easily put up it would not be such a huge issue.

So I wondered what solutions there are to implement a down for maintenance message easily whilst servers are upgraded. Be great to have some sort of switch, then switch back when finished. The only way I can think of is use the IP address swap in Linode, and have a Linode setup JUST to show this maintenance message.

Any other easy ways?

Thanks!

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Web Development Agency in South Wales

If you're going to be running another set of servers to fail over to so you can show a maintenance page, why not have them serve your actual site. People who want high availability generally use load balancing and health checks to set it up. I'm biased, but I'd recommend NodeBalancers:

https://library.linode.com/nodebalancers

- Les

On Linode, I've got about 11 servers, and on each of those ranges from several to say 40 websites. I assumed for Load Balancing I would need a second server for each server I want to mirror? So I dont want to invest in that at the moment, it will triple my costs I think.

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Web Development Agency in South Wales

Can IP Failover be used for this? Without using Heartbeat and Pacemaker which this page implies is being used:
https://library.linode.com/remote-acces ... p-failover

I cant find much info on what IP Failover is, only this configuration page.

I would not want a load balancer/mirror, I would just want a second server to serve a default page only when the first server is down, and never any other time.

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Web Development Agency in South Wales

Doing that requires having a second server, in which case you might as well take the aforementioned course and actually serve your sites from the second server.

The IP failover documentation is short because it's very simple: you enable for the IPs you want, on the Linodes that should also be able to use those IPs. After that, you can bring up those IPs on the Linodes you chose. We don't fail over the IPs automatically, and traffic only goes to a single Linode (whichever one you've brought up the IP on).

- Les

I would think mirroring multiple sites from multiple servers on one server may be a bit more tricky that just having a default maintenance page served for all sites, so I wanted to start at just a default maintenance page but will certainly look into having a mirrored site once I get this first step working.

How does one "bring the ip up" on a server? If Linode does not automatically repoint the main Ip to the failover server how do I do it?

Thanks

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Web Development Agency in South Wales

amityweb,
If you're running 11 Linodes, just redirect the DNS for all the sites on the Linode you're going to be performing maintenance on to a 'Maintenance' page on one of your other servers. If you're using Apache just set up a vhost file that has all the domains in it and point them to a generic 'Currently Unavailable Due To Maintenance' page (I'm not familiar with Nginx, but I'm sure it has the same option).

Well, that can be done yes, but I personally don't think thats a good way of doing because DNS changes can take a while, there will be no control over who sees what site on what server when. TTL can be reduced but that requires at least 24 to 48 hours planning. As stated one server has 40 domains, that will take ages. Some customers control their own DNS records which would be a pain to manage. So I don't think DNS changes is a good way to control switches to different servers, so ideally I am looking for an easier way.

The Apache/Nginx vhosts wont work, as that server would be down. Any IP repointing/redirection would need to be before traffic hits the server thats going down.

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Web Development Agency in South Wales

Failover environments don't necessarily need to be as powerful (or diverse) as the primary. As long as storage space isn't the concern, the failover environments can be configured for lower performance and greater consolidation.

Due to the complexity with database and file syncing (i.e. if the database changes on the failover server we need that synced back) then I am fine with a maintenance page stating site is down for maintenance and to checkback soon (just SOMETHING other that page not found).

What I dont understand at the moment though, due to lack of documentation, is if I do choose a failover server, how do I get that to kick in instead of the main server, because its stated above failover does not automatically work when the main server goes down. Sounds like I just need to switch the main servers IP addresses to point to a new server I have with he maintenance pages.

Thanks

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Web Development Agency in South Wales

I set up DNS Made Easy's failover option, and I fail over my Linode in Dallas to one in Fremont. DNSME will allow extremely short TTLs (IIRC I use 5 minutes and never had a problem) and they monitor very quickly, though local DNS caching is a pain I can't get around with this particular setup. It's not perfect, but as akerl noted I can mirror the site with a maintenance page that looks official and seamless even though it's on a completely different server, and I can even offer some limited services to my visitors. For simplicity I replicate MySQL as master/slave, so the slave linode is always current, though I don't allow DB writes so when the main server comes back online DNSME switches back automatically. Been doing this for years, and it's great piece of mind. Does wonders for the stress level, particularly when you've experienced an extended outage (not at Linode in my case).

I really wont be pursuing DNS changes for maintenance (the server upgrade took 30 minutes)... I control most domains but not all, I would have to go through customers to arrange DNS changes (they set the A record), and even then some recent upgrades involved over 50 domains, I'm really not going to change DNS for 50 domains many of which I have to arrange with customers. It really is in my opinion the worse way for a sort of failover (unless you know a server will be down for a very long time). I'm looking for a quick/simple way to point the original server Ip to a different one. Amazon have elastic IPs you can reassign easily.

I would like to look into Linodes IP Failover, I just cant see how to to get the "down" server IP to point to the failover server. I tried it, by choosing a failover server, then shutting down the main server, and restarting the failover one even, and added the IP as per static networking guide, but it didn't work. I cant see where to point the downed server IP to the failover one. If anyone knows how please could they let me know, documentation says nothing about this.

Thanks

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Web Development Agency in South Wales

Did Linode Support have any answers regarding the failover not working?

I understand the part about you not controlling all domains (and sorry I missed that), but with respect to it being the [worst] method to fail over, I think you're missing that with DNSME the failover is automatic. You define the failover IP address in advance, and your server is monitored 24x7. If it goes down, the DNS records switch within a minute or two with no action on your part. When your server comes back up, the DNS switches back, and you don't have to do anything. (or you can tell them to continue pointing to the failover server if you want.)

Just clarifying that for anyone else who reads your post and assumes that someone would have to change A records manually in advance of an outage. That is not how this system works.

You define the failover IP address in advance, and your server is monitored 24x7. If it goes down, the DNS records switch within a minute or two with no action on your part

I was hoping it was something like this, but it didn't work for me. I chose a Failover IP/server for another server, then I shut down the server. A domain which was pointing to the down server never did start pointing to the failover one. So I must have missed something somewhere.

Oh, but you mention DNS records change. So do you mean the DNS records in Linode DNS Manager? So therefore the domains need to be in there? My domains are not. I thought the failiver IP means the IP address would point to the failover server, not update DNS.

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Web Development Agency in South Wales