4
votes
3answers
113 views

Website high availability without load-balancer?

I'm considering options for changing a 'high availability' website that provides a service via an https api. The current setup is: Two self-contained VMs, from different cloud providers (AWS and ...
4
votes
2answers
683 views

Is round-robin DNS a possible solution for high availability?

Let's say I have 2 IPs for a given domain (round-robin DNS). If one the IPs becomes unresponsive, will clients try to connect to the other IP? or they will just fail to establish comunication with the ...
1
vote
3answers
70 views

If my DNS is a VM with HA do I need a secondary?

Same question would apply to mail server - if I have these running as VMs with failover / HA do I need to run a secondary / backup for either? This is a relatively small site (< 50 machines) so ...
2
votes
1answer
186 views

Simple redundancy setup using two servers in two different datacenters? [closed]

Scope of the question This question is solely about getting a client requesting a domain: example.com to one of the two available servers. How it is handled from there on, is another problem to solve ...
0
votes
2answers
39 views

DNS failover in virtual network

I have read some articles here and on other websites about the drawbacks of using DNS to implement high availability services. This is mostly due to the fact that configuring DNS to work efficiently ...
3
votes
3answers
403 views

How can I create a “fail whale” for my website?

I have a website that we load-balance across a few machines. The load-balancer (a Brocade ServerIron ADX) is on the local network. I know it has the capability to configure a "backup" ip address to ...
0
votes
1answer
155 views

Using Amazon route53 for high availability

Using Amazon Route53 DNS, is it possible to build a highly available setup pointing to multiple web servers not on Amazon? I don't need to worry about session stickyness. Let's assume I have two web ...
5
votes
3answers
3k views

If DNS Failover is not recommended, what is?

As a followup question to his very popular question: Why is DNS failover not recommended?, I think it was agreed that DNS failover is not 100% reliable due to caching. However the highest voted ...
2
votes
1answer
43 views

Setup a constant web application availability on Windows Server

I am a part of a team that is building an ASP.NET web system. We need to guarantee, that when the main hosting server with IIS is being updated, web site visitors get the special message that the ...
2
votes
1answer
527 views

Using LVS (Linux Virtual Server) for doing DNS HA

I have been trying to create an LVS DNS HA using CentOS 6.x: Piranha GUI to configure the DNS Pulse is the HA heart of CentOS LB IPTables to configure marks on the packets since DNS uses TCP and UDP ...
2
votes
2answers
134 views

Swap DNS entry on failure

I'm building an application that requires high-availability. We currently run: 4 webservers, 2 varnish servers (both with Pound for SSL proxy), 3 Cassandra nodes. The varnish servers are used as ...
0
votes
1answer
616 views

DNS failover in a two datacenter scenario

I'm trying to implement a low-cost solution for website high availability. I'm looking for the downsides of the following scenario: I have two servers with the same configuration, content, mysql ...
4
votes
4answers
3k views

DNS Round Robin: Do browsers stick to one IP as long as it is online?

How do most browsers behave if they get multiple A-records from the DNS server? Do the stick to one IP as long as it is reachable (and only use another if the IP is down)? Or do they switch all the ...
7
votes
3answers
4k views

What is the difference between Anycast and GeoDNS / GeoIP wrt HA?

Based on the Wikipedia description of Anycast, it includes both the distribution of a domain-name-to-many-IP-mapping across many DNS servers as well as replying to clients with the most geographically ...
2
votes
2answers
2k views

Load balancing / Failover for multiple VPS's set across different datacenters

I know many variants of this question has been asked already, but I still can't find a good answer to my needs. What I want to do is setup a few (2 at minimum) VPS's to host my web apps on. I'd like ...
2
votes
3answers
376 views

Looking for a DNS Hosting provider with automatic failover and role switching

I need to set up automatic failover with two SQL Server Instances and mirroring. There are several DNS hosters (such as DNS Made Easy and Netriplex) out there providing automatic failover. The are ...
2
votes
4answers
5k views

DNS Round Robin: Multiple Nameservers VS Multiple A Records?

Note: This is a follow-up to my previous question regarding DNS Failover. The Goal: to make the client's web browser select the next available server if one is down instantly. I've read somewhere ...
11
votes
7answers
7k views

Avoiding DNS timeouts when a dns server fails

We have a small datacenter with about a hundred hosts pointing to 3 internal dns servers (bind 9). Our problem comes when one of the internal dns servers becomes unavailable. At that point all the ...
2
votes
2answers
596 views

Does my BIND zone really provide redundancy and load balancing?

We have the following IP addresses (for example): 1.1.1.1 2.2.2.2 Each hosts the same website, but on a different server. We want to do some really simple load balancing by having web users visit a ...
8
votes
3answers
781 views

Global high availability setup question

I own and operate visualwebsiteoptimizer.com/. The app provides a code snippet which my customers insert in their websites to track certain metrics. Since the code snippet is external JavaScript (at ...
6
votes
3answers
516 views

Apache availability with the two front-ends on diferent locations. Is it possible?

I have to locations (office and service providers). One DNS(bind) serving our domain as authoritative, and a service provider webserver with our corporate web on a private server. So.. Now we are ...
9
votes
8answers
5k views

High Availability DNS Hosting Strategy?

I'm trying to find a few options of ways to do high availability DNS hosting for a few existing websites. This morning, the company I work for was brought to its knees because the DNS hosting we have ...
0
votes
3answers
298 views

Site specific URL DNS Issue

I have a large number of worldwide sites that need to access a service via a URL. The site URL cannot be altered as it is set centrally. The service is hosted locally at each site, as connectivity ...
2
votes
2answers
438 views

tools for geographical redundancy

I'm writing a spec for a high availability application. I need a low budget solution to be able to failover between two data centers. Replicating databases and content I'll be able to manage solutions ...
1
vote
2answers
489 views

hosting a website on multiple hosts

Is there a way to host a website on multiple hosts. exactly the same site, for example on hosting companies HostingABC and HostingDEF? In case there is ever a problem with HostingABC (either a ...
51
votes
11answers
13k views

Multiple data centers and HTTP traffic: DNS Round Robin is the ONLY way to assure instant fail-over?

Multiple A records pointing to the same domain seem to be used almost exclusively to implement DNS Round Robin as a cheap load balancing technique. The usual warning against DNS RR is that it is not ...
1
vote
1answer
578 views

Could a Geo-DNS create availability issues?

Geo-DNS can be used to balance traffic across data-centers. I found this (old) article where it is described why Geo-DNS implies availability issues if one of the IPs (data centers) goes down. Could ...
1
vote
5answers
2k views

Free DNS software with failover support? [closed]

I'm looking for DNS software that can accomplish the following: Check health of all A records at set intervals If server is unresponsive after multiple successive checks, replace A record with a ...
1
vote
3answers
264 views

Software for failover across multiple external hosts

I have multiple webservers with the same content, hosted across different providers. However, I can't seem to find a nice, simple failover solution. Load-balancing software (Pound, HAProxy, etc.) are ...