I am trying to do a fail over solution with round robin dns. Our dns is served by windows and our web servers are setup with Linux..
I know round-robin does not by default do a fail over, however my understanding is that a script can be used to remove the failed server for dns, is anyone aware of something that will do this for windows?
iptables -t nat -A POSTROUTING -o eth0 -j SNAT -p tcp --dport 80 --to-source 1.2.3.4-1.2.3.6
If I'm understanding the iptables man correctly this rule should round-robin outgoing http requests over the IP range, instead it's sticking to the first IP no matter how many connections I make.
We have a few IIS servers that will be acting as front end for our users to split off the load.
Currently, we have one IIS with 1 SSL. we are going to do round robining for the FQDN to span a few IIS servers. I just wanted to make sure we would not run into any issues with the certificate. I was thinking of installing it on one server after generating the CSR and then once the root trusted is in place, export it and import it in all the other servers. Do you think this would be an issue at all? is there a better way?
additionally, the certificate is about to expire, I need a certificate with $1mil insurance, what do you think is the best deal (trusted source) going around? should I do the ones with 256bit too or have you seen any conflicts, do they auto negotiate if the client can only support 128bit?
Round-robin and UserDirs
I just setup a round-robin so that my website is always available even if one of the 2 servers goes down. It works like it should, however, i can't access the userdirs from server2. The userdirs are located on server1.
It's setup like this:
www1.domain.org is server1
www2.domain.org is server2www.domain.org is the round-robin. I have 2 WWW's pointed with an A record to each of the server's IP addresses.
On server 1 i have 2 userdirs which are accessible through www1.domain.org/~user . They should also be reachable on www2, because if they are not, they wont be accessible half the time due to the round robin.
I therefore added a .htaccess in www2's root document directory with the following info:
Redirect /~user1/ http://www1.domain.org/~user1/
Redirect /~user2/ http://www1.domain.org/~user2/
So when i go to www2.domain.org/~user1/, i should be automatically be transferred to server1... but all i get is a 404 error page. It works perfectly when accessed on www1. I don't see what i'm doing wrong. I thought it might be the userDir setting in apache that might be causing trouble.. but that is turned off on server2, so that should not be the problem. Anyone here have any idea how to access the user dirs via server2?
Looking for redundant setup, round robin?
I'm looking to make high availability setup, and wondering how many of you have made it so?
we are looking to multi-home the page with a round robin setup, using multiple VPSs/dedicated servers geographically different locations.
Right now i'm still looking at "stale" DNS setup, no automanagement of servers down. Is there a service/software which already offers automatic changes of zones for removing servers which are down, and adding them back when they get back online?
Do i need to custom tailor everything?
I run a site with about 1,000,000 unique visitors per month and recents server failures made me decide to get a failover server to minimize downtime. My goal wasn't to get 99.999% uptime but to be able to be back on track after a failure in a "reasonable" amount of time. After evaluating several solutions, I decided to go with DNS failover. Here's how the setup work:
1) mydomain.com points to main server with a very low TTL (time to live)
2) failover server replicates data from main server
3) when main server goes down, mydomain.com is changed to point to failover server
The drawback is the DNS propagation time since some DNS servers don't honor the TTL and there is some caching happening on the user's machine and browser. I looked for empirical data to gauge the extent of the problem but couldn't find any so I decided to setup my own experiment.
The Experiment
==============
I start with mydomain.com pointing to the main server with a TTL of 1800 seconds (1/2 hour). I then change it to point to the failover server which simply port forwards to the main server. On the main server, I periodically compute the percentage of requests coming from the failover server which gives me the percentage of people for which the DNS change has propagated.
I made the DNS change at exactly 16:04 on 06/21/06 and here are the percentage of propagated users:
06/21/06 16:00 0 %
06/21/06 16:05 3 %
06/21/06 16:10 20 %
06/21/06 16:15 37 %
06/21/06 16:20 59 %
06/21/06 16:25 69 %
06/21/06 16:30 76 %
06/21/06 16:35 80 %
06/21/06 16:40 86 %
06/21/06 16:45 90 %
06/21/06 16:50 91 %
06/21/06 16:55 92 %
06/21/06 17:00 93 %
06/21/06 17:05 94 %
06/21/06 17:10 94 %
06/21/06 17:15 95 %
06/21/06 17:35 95 %
06/21/06 17:40 96 %
06/21/06 17:45 97 %
...
06/22/06 10:40 99 %
So even after 18 hours, there is still a certain percentage of users going to the old server so DNS failover is obviously not a 99.999% uptime solution. However, since more than 90% of the users are propagated in the first hour, the solution works well enough for me.
I host my own server but need to get a failover server in the case it goes down. Does anyone know of any companies that host failover servers that will run off my own server?
View 7 Replies View RelatedI'd like to create a failover server, a complete and identical copy (as much as possible) of my primary server, which becomes "primary" when the first server dies.
I've been reading a lot about this subject and i've seen an already working method which uses rsync and MySQL replication.
Has anyone managed to create such a system? is there someone with experience or can point me to a relevant web site?
CentOS, LAMP, webmin.
I have ibeat.org running on one server.
Now I want to make a status subdomain on another server.
ibeat.org on one - status.ibeat.org on another.
I've edited the master zone on server one and added status.ibeat.org. and www.status.ibeat.org. ... and pointed it with A and CNAME to the other server and related IP...
I have also created the subdomain on the second server.
So my question is what should I do to get this working? This isn't!
I want to have a status link on the ibeat site ... and also:
... if server one with ibeat.org fails make it open status.ibeat.org?
Should be pretty simple - but can't get my head wrapped around it.
So, there is my example. I have two servers in different locations. First one is the main server with all the data and the second one has just simple notice like "We will be back soon".
Now, if I set the primary DNS server on main server and secondary DNS on second one (but with different A records), will users actually get the server two if main server is down?
Will this work or not? I want 100% access to the site, at least to the server with only notice (I don't need data from main server). I can set the round robin, but I don't need load balancing (actually I want access only main server), but just if main server is down to go on the second one.
It seems the more places we can put servers, the more places boss-man wants them
We're setting up an external network to test back into our network from geographically/carrier diverse locations. We've got about 15 hosts up, but most are in the states, one in london, one in amsterdam, one in frankfurt and one in hong kong.
The current wish list of locations includes -
- Japan
- S. Korea
- Australia (holy cow bw is expensive in sydney! is anyone charging less than $500 per Mb?)
- Paris, France (we have one quote in, but it is pretty pricy)
- Italy
- Spain
- Sweden
I'm doing research and have submitted rfq's to companies in most of these locations, but was hoping for personal recommendations of hosts you have used.
Does anyone know any tools or scripts that you can run to do email round trip monitoring (eg, sending and ensuring it’s received within x minutes)?
Not looking for a solution that is hosted (eg, websitepulse.com) but for something that can be run off a machine locally.
We was unable to log in into Round cube with any email account. URL....
View 2 Replies View RelatedI want to add a DNS Failover automated service at my server, in order that when it goes down, the DNS Failover enters in action and it will redirect all the traffic to a second backup/failover server (hosted at a different location).
So in order to do this i have been looking around and i have found dnsmadeeasy, and i found their offer interesting.
But i still have some question and doubts on how a dns failover service works. So maybe someone can expalin it to me.
My question and doubts:
1 - If i use for example the DNS failover from dnsmadeeasy, i would have to buy 2 servers where one is the principal server and the other is a backup/failover server, so when my main server goes down, the dnsmadeeasy will detect in a automatic way, and redirect all the traffic to my backp/failover server. After my principal server goes back online, dnsmadeeasy will automatic redirect all the traffic to the principal server.
Im i correct? Or i understound wrong how this works?
2 - I use my own Nameservers and i want to continue to use my own nameservers. So if i use dnsmadeeasy services, i will be able to continue to use my nameservers as ns1/ns2 and then i will add the dnsmadeeasy ns3/ns4...as the following example:
ns1.mynameservers.com
ns2.mynameservers.com
ns3.dnsmadeeasy.com
ns4.dnsmadeeasy.com
ns5.dnsmadeeasy.com
ns6.dnsmadeeasy.com
Correct?
I am planning to rent 2 managed dedicate servers with windows server 2008 and ms.sql 2008.
which I will use one for web application and 1 for database server.
why people usually divide them into web and database server? is it for security or performance reason?
Which one you prefer to choose?
- 1 server for web and 1 server for database.
or
- 1 server(web and database) and 1 server for failover
In making my plans for my web hosting business I plan to start, I've thought about a failover but wanted to know the best way to set it up.
I would ideally like to start with something like getting a small shared hosting solution (not reseller, just shared) at a reliable hosting company. On this hosting plan, I will host a simple 1 page site that says my company is having technical difficulties, reminds people that data is safe, and provides any contact information accessable (like e-mail/phone/etc...).
I already have DNS setup offsite.
I would like that if my server(s) go down for any reason, whatsoever, that DNS automatically starts serving the temp site.
so if my server suddenly goes down, [url]or [url]suddenly goes to the offsite shared hosting plan.
This would not provide customer site redundancy. This would only ensure that if anything happens to my service, customers have a page available that explains what is happening and has information to contact us to get more details.
We have 2 Cisco PIX 515's in a failover configuration (7.1 series IOS). We have available both a serial failover cable and adequate switch capacity to allow using either the serial or LAN-based approach. We have no current plans to locate the firewalls physically apart.
We have plenty of info on how to configure either, but no recommendation on which is the better choice.
I have a reseller account with a company that often has spontaneous DNS errors, and this, as you know looses us money. I also have a dedicated server running a panel exclusively via IIS. Is there a way I can set up my dedicated (Windows) box and my reseller account in a mirror way, so if one of them fails, the other will take over.
There are no file changes often, more database then anything. Is this possible?
Main necessities are:
-Mail Servers
-MySQL Servers
-PHP5
-Cron jobs
(Or, if a shared hosting company can accommodate this somehow and is relatively inexpensive.
Basically have 2 hosting accounts at different providers...each set-up for the same domain name...and then somehow wtih DNS make it so if host #1 goes down traffic goes to host #2 (which would basically be a splash screen explaining that host #1 is down and will be back soon).
DNS isn't my strong point, but I do know you can do this with MX records...so if the first server fails it tries the next until it gets a working one or reaches the end of the list. I'd just like to do it is A records.
It wouldn't be as simple as setting the nameservers like this would it?
ns1.host1.com
ns2.host1.com
ns1.host2.com
ns2.host2.com
Would it use the host1 nameservers as long as they're online, and if not failover to the host2 nameservers? If so, great, but what if the host1 nameservers are online but the server itself is not.
Assume, a DNS failover service would change the DNS from server 1 to server 2 when the first one is offline. This will be changed quite fast, however isn't it true that some visitors still experience a downtime of a couple of hours (saying that the main server will be offline for 6 hours) as their ISP might not update DNS that frequently?
So basically, what is the added value of a failover service?
What happens if your primary nameserver goes down? Meaning that it goes completely off the net, not even denying dns requests but completely ignoring them.
I'd guess that resolvers would query the secondary NS after a specified timeout, but what is that timeout set to? Does it differ from ISP to ISP? How much of a slowdown are we looking at for end users?
I was wondering what sort of systems have you guys implemented for ensuring your website remains online.
Iv attached a pic of what I think are the best options.
What do you think?
Also, am I correct in my assumptions about DNS?
I'm building the infrastructure for a live event site.
I have specced 8 app servers but I'm still unsure with regards to MSSQL.
The site functionality makes a single write to the DB with no reads. A simple option would be to have a MSSQL DB instance on each of the APP servers and simply collate the information after the event.
I've also been looking at the mirroring function of 2005 as it would mean we could get away with two MSSQL servers instead of 8.
Has anyone used MSSQL 2005 Mirroring? Is it easy to setup and maintain? Any caveats?
We want to provide failover service at our server using dnsmadeeasy service.
So we have already buy the "failover server" (running linux/plesk), and now we are looking to find the most adequate / best way in order to keep the 2 servers sincronized, in order that if "main server" goes down, all the traffic can be redirect to the "backup server" using dnsmadeeasy.
on scripts/software to keep 2 linux servers sincronized in a failover setup?
I'm working for a client who has an e-commerce site currently hosted on a shared hosting solution.
He is now looking for 100% uptime (as near as), so I have suggested that we get 2 VPS and use DNS monitoring to switch servers as required (from DNSmadeEasy).
This is all fine, and the websites files/images do not change often, so I can use rsync every so often to sync these. Not a problem.
What does change frequently is the mySQL db for the site.
I've been looking at MySQL replication, but this seems to be no good. If one server goes down, then the other one takes over, they don't automatically sync themselves after they come back up. It seems MySQL cluster is best, but this needs 3 servers and they all need to be on the same LAN.
I've read you can set MySQL replication to MASTER-MASTER so that it acts like a cluster, and resyncs itself as required.
I was wondering if this is the right section.
Well my problem is, we have 2(ABC and XYZ company) internet connection and sometimes,
the ABC connection is not active and we're disconnected for about 2-4 minutes interval to get the XYZ internet connection online.
My question is - Is there a software that will automatically set the XTZ internet connection to active? Something like if the ABC connection is down, the XYZ will supply internet connection right away.
I have been searching and searching for a solution. We are currently using one single vps to host some of our clients. We are finding more and more that we need to have some redundancy.
I have looked at using DNS failover using RSYNC/mysql replication etc with two servers, but just dont like the idea.
I have also looked at hosts like imountain etc that use h-sphere. I dont like this setup because services are split onto single machines. For example mail is done on one single server, therefor if that server is down, mail is down.
What I am looking for:
I am trying to stay in a budget of 150/month or less.
I would like to get one of the two options here:
option 1: two vps's or dedi's that technically act as one(a true cluster) then on top of that is OS and control panel and done. This solution doesnt allow for whole datacenter outages, or network issues.
option 2: Two geographically placed vps or dedi's that are somehow either load balanced, or failover.
Ultimately our goal is to have high uptime, but we dont really have much server load.
Basically failover is ok as loads are always low anyway, but if we are paying big $$ it would be nice to have it load balanced.
Please let me know if my expectations are way to high or my price is way too low. I need to find a solution here somehow and if I cant find anything will most likely just go with DNS failover.
to do a standby fail over solution for a web server box. I would like the solution to be automated so that in the event of a failure the change happens without any manual intervention.
I have 2 identical hardware boxes and bandwidth is not an issue.
