DNS configuration to distribute traffic to multiple host on google cloud - dns

We have 2 servers hosting a particular service on google cloud. How to do a simple round-robin DNS configuration to distribute the load?

According to this thread Google Cloud DNS does not support round-robin.

You can set up DNS round robin with Cloud DNS simply by adding more than one IP address to your DNS record.
You might want to look into Google Compute Engine's Load Balancing options. This will allow you to have one IP address that sends traffic to your two servers. This has a few advantages, including that you can configure it to automatically stop sending traffic to an instance if it fails a health check.

Related

How to redirect traffic hosted on an azure endpoint (DNS/static IP) to different external IP address

Question: How do I host an endpoint in azure which allows me to redirect internet traffic at will between azure and aws services?
I am hosting two kubernetes clusters - one in Azure and the other in AWS. I want to be able to:
1. redirect the traffic at will to either aws or azure, whilst retaining the public dns endpoint.
2. fail over manually [and pref automatically too] to the aws cluster. What is the best way to host the endpoint in azure?
Requirements:
The traffic needs to be redirected immediately - no caching issues and stale loads!
Ability to configure failover - i.e. specify that Azure is hot and AWS is the failover service - the traffic should be automatically redirected as soon as Azure goes down.
I have looked at Traffic Manager, Load Balancers and Application Gateway. Not sure which one (if any) of these is best.
traffic manager wont work for you, since its a dns service, so caching will happen (admittedly its the best solution if you set dns cache to 5 seconds or something). application gateway allows you to specify an ip address as an endpoint, load balancers only work when attached to vms inside azure. But application gateways dont allow to failover at will. you would need to block the probe to failover.
Azure Front Door might be the solution for you (like the other answer mentions)
You can have a look into Azure Front Door Service for your usecase.
Look into this https://learn.microsoft.com/en-gb/azure/frontdoor/front-door-overview

Azure Load balancing to Multiple Sites with Disaster Recovery

I am trying to configure applications on 2 different Azure sites having their local load balancing capabilities. I can use Traffic manager to distribute the traffic and have weighted routing to force everything to my primary site.
But i want this to occur automatically where i can map a service pointing to the internal load balancers at both sites and evaluate the sites are up and running or not to decide where to forward the traffic. This will allow me not to manually configure the Traffic Manager in case of disaster.
Note : The services are hosted on IIS on IaaS VMs. ILB1 and ILB2 are respective loadbalancer for Site1 and Site2.
Any help is appreciated!
Thanks
As far as I know, we can't add internal load balancer as traffic manager endpoints.
But I want this to occur automatically where I can map a service
pointing to the internal load balancers at both sites and evaluate them
sites are up and running or not to decide where to forward the
traffic.
By default, we can set multiple sites around the world with traffic manager, traffic manager will probe the health of all sites, forward network traffic to the right site.
We can use traffic manager profile to manage network traffic, traffic Manager profiles use traffic-routing methods to control the distribution of traffic to your cloud services or website endpoints.
For example, we create website 1 on site 1 (primary site), create website 2 on site 2. If we use the weighted method, network traffic will to site 1. When site 1 is down, traffic manager will know site 1 was down, will route network traffic to site 2.
Traffic manager works as a DNS level Load Balancer, it will route network to the available site by default.
About traffic manager probe settings, we can via the Azure portal to modify it, like this:
By the way, if you want to use traffic manager, we can add public IP address to traffic manager endpoint.
Update:
As a workaround, we can deploy a S2S VPN between two locations, and use Haproxy to work as load balancer, then add two VMs to public load balancer, like this:
We can use Haproxy to set primary website, more information about Haproxy, please refer to this link.

How to do load balancing / port forwarding on Azure?

I am evaluating the convenience of moving to azure. Currently, I am trying to figure out how to balance the load and make routing for different websites on the same machine. I saw tutorials where a user created a separate LB on a different VM. I also found many articles about the possibility to balance the load using Azure load balancing.
So I assume both are possible, is that correct?
I would like to know how to connect between machines on azure. Would it be possible to do so using a local ip, machinename, or dns?
I also need to figure out how to forward traffic to different ports based on http header, is that possible without a seperate machine as load balancer? I see the endpoint config in my azure dashboard and found the official documentation, but unfortunately it's not enough for my understanding.
Currently, I am trying to figure out how to balance the load and make
routing for different websites on the same machine.
You can have different web sites on the same machine by configuring virtual hosting on IIS. This is accomplished using host header. VM, Cloud Service or even Websites supports this functionality. VMs and Cloud Services should be pretty straight forward. Example using websites:
Hosting multiple domains under one Azure Website
http://blogs.msdn.com/b/cschotte/archive/2013/05/30/hosting-multiple-domains-under-one-azure.aspx
I also found many articles about the possibility to balance the load
using Azure load balancing.
LB for VMs are as easy as creating a load balance set inside endpoint configuration wizard. Once you create a balance set, for example, enpoint HTTP port 80, you can assign this balance set to any VM on the same cloud service. All requests to port 80 would be automatically balanced across all VMs in the set.
So I assume both are possible, is that correct?
Yes.
I would like to know how to connect between machines on azure. Would
it be possible to do so using a local ip, machinename, or dns?
You just have to create a virtual network and deploy the VMs to it. Websites (through preview portal only), Cloud Services and VMs supports VNet.
Virtual Network Overview
https://msdn.microsoft.com/library/azure/jj156007.aspx/
I also need to figure out how to forward traffic to different ports
based on http header, is that possible without a seperate machine as
load balancer?
Not at this moment. Best you can have with native Azure Services is a 3-tuple (Source IP, Destination IP, Protocol) load balance configuration.
Azure Load Balancer new distribution mode
http://azure.microsoft.com/blog/2014/10/30/azure-load-balancer-new-distribution-mode/
depending on how you're deploying there's a couple of options:
first of all: LB sets in VM's in a cloud service. For this the Cloud service acts as the LB. this can only be achieved when using a standard sku VM.
second of all in Azure WebApps : load balancing is achieved automagically when deploying through standard means, since scaling is foreseen here.
Third of all there's Cloud Services with roles, who also do this "automagically".
Now none of that seem to apply to your needs. you can also start thinking about using traffic manager, something with a little more bite :-)
have you read this article by any chance? http://azure.microsoft.com/en-us/documentation/articles/virtual-machines-load-balance/
I'd like to advise you to add different endpoints to your VM's work with traffic manager and ake sure you IIS has all the headers on the correct ports (cause i'm assuming that's what you're doing already)

Azure Traffic Manager

Fast question is it possible to have Azure Traffic Manager
I would like to rent dedicated servers in 3rd party suppler and to load balancer from Azure
Question 1:
Can I setup this scenario? and use the load balancer from Azure?
Question 2:
Will I pay Outgoing bandwidth
Question 3:
Will you share for website with 10 000 000 page views per month how much you pay for DNS look ups as average.
Question 4 please suggest same service competitors... Google, Amazon, Rackspace I already know
The link you provided to the article already answers #1 and #3. Yes you can set this up. Billing is done by DNS lookup at $0.75 per million lookup, so your 10m page views will cost at most $7.50, but this isn't taking into consideration DNS caching which will drastically lower this (already very low) cost.
Question 2 is not an Azure Traffic Manager related question. No bandwidth goes through ATM so there is no charge. I am sure you will pay bandwidth charges with whatever 3rd party datacenter provider you are going to use.
I don't understand question 4. What do you want suggestions for? A cloud provider? There are lots of good ones but it depends on your scenario.
Azure Traffic Manager is a DNS routing system. It is similar to the routing features of AWS Route 53 (although Route 53 is a more full-featured DNS system).
Azure Traffic Manager uses DNS to point incoming traffic to different endpoints, which can be either within Azure or external urls. Because it uses DNS, it doesn't actually see any of the data itself, it just translates something like myapp.trafficmanager.net to 'webserver1.example.comorwebserver2.example.com` based on your rules and setup.
You can use round-robin, weighted or performance (which directs to the geographically closest address you have setup). You can further use Azure's DNS or another DNS system to use your own (sub)domain to CNAME to the trafficmanager.net domain name.
Load balancers like Azure Load Balancers and Amazon's Elastic Load Balancers are used to actually spread the traffic itself to different machines or services. Each work only with services hosted with the cloud provider so Azure Load Balancers can be used to load balance Azure VM's but not some servers you have hosted elsewhere.
Load balancers have bandwidth charges because they actually pass through the traffic. Azure Traffic Manager just has DNS query charges because that's all it does.
In your case, yes you can use Azure Traffic Manager to point to several external endpoints for your dedicated servers. You can also nest Traffic Manager profiles so that you can first use geo-location then round-robin. Azure Traffic Manager does support basic http/https monitoring to make sure the endpoint is still active.
Because it is based on DNS, there will always be a lag between changes with the TTL value and how clients cache DNS addresses. This is inherent with all DNS routing. To be extra safe, you can use Azure Traffic Manager to route to your datacenter and then run your own load balancing software locally to spread the load among servers.

Can CloudFlare perform automatic failover to a different backend?

I am looking for an easy way to fail over to a different DC quickly, does CloudFlare offer anything special in this regards with things like health checks or is it just like a standard DNS service?
Update: CloudFlare started a closed beta for the Traffic Manager feature which allows to do exactly this kind of failover:
https://www.cloudflare.com/traffic-manager/
AWS Failover:
The following solution seems to work well when you are hosting your backend system on AWS:
I setup a AWS Route 53 zone with a separate domain (e.g. failover-example.com). Route 53 allows you to setup health checks on the backend server (e.g. the load balancer) with DNS failover. AWS will remove the unhealthy backend system from the DNS record list.
In cloudflare I setup a CNAME for example.com record to failover-example.com and activate the cloudflare proxy on example.com.
The result is that the browser resolves the IP address of example.com to a cloudflare IP address. Cloudflare queries the AWS DNS server to lockup failover-example.com. Cloudflare fetches the content from the resolved IP address and returns the content back to the browser.
In my tests the switch to the other backend system occurs after ca. 20 seconds.
The separate domain is required because cloudflare does not route the traffic through the proxy when the CNAME is a subdomain of example.com.
I have tried to visualize the failover. In theory the failover works with any DNS failover capable service and not only with Route53:
The browser connects always with CloudFlare and hence a DNS failover of the backend system does never effect the browser of the user.
We don't have automatic failover at this time (something we're looking at). We can support the additional DNS entries in your zone file, of course, but you would currently have to manually make the change in that circumstance.
To add -- in the mean time, I'd recommend looking at https://runbook.io
Several other DIY options:
http://blog.booru.org/?p=12
https://vpsboard.com/topic/3341-running-your-own-failover-dns-setup/
https://github.com/marccerrato/python-dns-failover
You'd want to decide if these are the right options for you, of course.

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