I use Azure Application Gateway. When I review the documents, I only see round-robin distribution of incoming traffic, cookie-based session affinity, URL path-based routing for Application Load Balancer. Is there any way to use Least Connection for that. This is available on AWS, but I couldn't see it on Azure.
Yes, you can do it via https://resources.azure.com/
You should open that resource; find your RG and APP GW and you will see setting
routingmethod -> roundrobin and you can change it to leastresponsetime
https://learn.microsoft.com/en-us/azure/application-gateway/how-application-gateway-works#how-an-application-gateway-routes-a-request
Round-robin (or cookie based affinity) is all you can do. Kinda lame.
Related
So I am looking at using Azure App Gateway to overcome a set of legacy servers (Win2003) that will not support TLS 1.2 and therefore come March+ 2020 the client browsers will not be able to access the site.
So my question is can I use AZ App Gateway to terminate the SSL and route traffic onto a set of Windows Load Balanced servers in our datacentres?
Has anyone done this before?
You can certainly do this, but Azure Front Door would be a better option, I believe (if you trust IP restrictions, I think that would be the only way to secure endpoints). They would allow you to offload SSL and offer some other nice features. And you don't have to create site-to-site vpn and maintain it.
What are some legitimate use-cases for fronting an Azure "Web App" service with a reverse proxy (i.e. ARR)?
I'm specifically interested in security considerations. For the purposes of this question, let's assume load balancing is handled by the Azure load balancer and the proxy would not perform any additional features such as caching or compression.
The Azure Load Balancer is a Layer-4 component. ARR is a Layer-7 router, therefore it can do sticky sessions (instance affinity) and health checking.
In App Service it also does TLS offloading, which is pretty nice since your application code only has to deal with plain HTTP. More on that here: https://stackoverflow.com/a/38726543/4148708
If you don't need/want any of that, then by all means, go to Cloud Services, VM Scale Sets or vanilla VMs.
Currently I have a Service Fabric cluster with 2 stateless services hosting Asp Web APIs. While creating the cluster also appropriate Azure Load Balancers got created.
Now I would like to add Application Gateway in front of my cluster for various reasons like SSL offloading, url-routing etc.
I'd like to understand how to configure the Application Gateway correctly. I see 2 options, not sure which one is valid:
Application Gateway replaces the existing Load Balancer and points directly to SF services hosting WebApi
I keep existing LB configuration and Application Gateway points to this LB (seems like 1 LB solution too many)
Which one is correct? Any advise how to configure?
Approach 2 is what we are using, We have kept the load balancer and that is routing any request received from the Application Gateway. We found this to be easiest and simplest choice, as this involves minimum changes to be done in Application Gateway.
Your two web api's can run on every node in the VM scale set. The Azure Load Balancer is used to distribute traffic over those nodes. Targeting a single service on a single node will reduce scalability and fault tolerance.
You could use the App Gateway to translate incoming request to different ports on the Load Balancer. (E.g. direct traffic to API 1 #url ~/1/ and API 2 #url ~/2/)
Favor using load balancing rules (using all nodes) over NAT redirections (to single nodes). This way you'll have a performant, reliable system.
Solution 2 would also provide possibly to create VPN connection e.g to manage your cluster. Then no need to expose management endpoint to the public. Internal lb also brings on additional features to utilize in the future.
I would go with your first option and to implement it create / modify your ARM template so that it doesn't contain the load balancer and instead contains the application gateway.
Here is a link to the quick starts for ARM templates which you can use. There isn't an out of the box example for service fabric with a gateway but it will give you a great starting place.
link
My company wants something like the Application Gateway to be a scalable entrypoint of all incoming requests, with SSL offloading, and balance those requests to external web servers, which are not on our Azure subscription, but belong to the company.
If Application Gateway is indeed the recommended way, how can I declare in the XML configuration file something like that? And if it's not, what's the best way I can achieve that?
application gateway is an option to achive this but by using an application gateway you use an AzureVM ressource. The scalability is ok but we have to pre-create more application gateways in case of a scale out. For a scale down you should also check first how to reroute traffic from the current gateway to the others before you scale down.
i would reccomend an another design. by using azure app-services. this is a webserver farm as a service. in the webserver is IIS running and you can create a forward / redirect reverse proxy or ARR. check out point like azure topics like Application request routing and reverse proxy:
http://blogs.iis.net/carlosag/setting-up-a-reverse-proxy-using-iis-url-rewrite-and-arr
http://www.iis.net/learn/extensions/url-rewrite-module/iis-url-rewriting-and-aspnet-routing
regards
patrick
How can I maintain users to get redirected to the same Server in a Load-Balanced Web Apps
Your answer will be very helpful
Traffic Manager directs the user to the appropriate region, but assuming you have your web app scaled out to at least two instances, ARR (Application Request Routing) is what directs each request to a specific instance of the app.
ARR has a feature called Session Affinity which is enabled by default. It uses an ARRAffinity cookie to attempt to route all requests from a client to the same instance of your application. I say "attempt" because, the cloud being what it is, instances of your app can come and go due to autoscaling or maintenance activities.
Your best bet is to use Azure Traffic manager. When setup correctly it will route users to the proper cloud service in their region and provide them with the best possible experience.
More information can be found here
Azure Traffic Manager
Azure Traffic Manager Documentation
Traffic Routing Methods