Installing Haproxy On Windows' title='Installing Haproxy On Windows' />List of Client Implementations Issuance Tech. ARR as a Highly Available Reverse Proxy in Windows Azure. With the general availability of Windows Azures Iaa. S solution last year, weve seen a significant uptake in migration of legacy solutions to the Windows Azure platform. And with the even more recent announcement of our agreement with Oracle for them to support their products on Microsofts hypervisor technology, Hyper V, we have a whole new category of apps we are being asked to help move to Windows Azure. One common pattern thats been emerging is for the need for LinuxApacheJava solutions to run in Azure at the same level of density that is available via traditional hosting providers. I understand the concept of Path MTU but not sure if its required that systems in the same network should have the same MTU. For example my hosts MTU is 9000 and. If you were an ISV Independent Software Vendor hosting solutions for individual customers, you may choose to accomplish this by giving each customer a unique URI and binding that to a specific Apache module, sometimes based on a unique IP address that is associated with a customer specific URL and a unique SSL certificate. This results in a scenario that requires multiple IPs per server. As you may have heard, the internet starting to run a bit short on IP addresses. So supporting multiple public IPs per server is a difficult proposition for a cloud, as well as some traditional hosting providers. To that end weve seen new technologies emerge such as SNI Server Name Indication and use of more and more proxy and request routing solutions like Ha. Installing Haproxy On Windows' title='Installing Haproxy On Windows' />Proxy, Free. BSD, Microsofts Application Request Routing ARR. This is also complicated by the need for delivery highly available, fault tolerant solutions that can load balancing client traffic. This isnt a always an easy problem to solve, especially using just application centric approaches. Download Virtual Dj Keyboard Shortcuts. They require intelligent, configurable proxies andor load balancers. Precisely the kind of low level management the cloud is supposed to help us get away from. Opensource TCPHTTP loadbalancing proxy server supporting native SSL, keepalive, compression, CLI sticktables, custom log formats, header rewriting, redirects. But today, Im here to share one solution I created for a customer that I think addresses some of this need. Using Microsofts ARR modules for IIS, hosted in Windows Azures Iaa. S service, as a reverse proxy for a high density application hosting solution. Disclaimer This article assumes you are familiar with creatingprovisioning virtual machines in Windows Azure and then remoting into them to further alter their configurations. Additionally, you will need a basic understanding of IIS and how to make changes to it via the IIS Manager console. Im also aware of there being a myriad of ways to accomplish what were trying to do with this solution. This is simply one possible solution. Overview of the Scenario and proposed solution. Heres the outline of a potential customers scenario We have two or more virtual machines hosted in Windows Azure that are configured for high availability. Each of these virtual machines is identical, and hosts several web applications. The web applications consist of two types. Stateful web sites, accessed by end users via a web browser. Stateless APIs accessed by a rich client running natively on a mobile device. The state of the web sites is stored in an in memory user session store that is specific to the machine on which the session was started. So all subsequent requests made during that session must be routed to the same server. This is referred to as session affinity or sticky sessions. All client requests will be over SSL on port 4. URL specific to a given applicationcustomer. Each siteURL has its own unique SSL certificate. SSL Offloading decryption of HTTPS traffic prior to its receipt by the web application should be enabled to reduce the load on the web servers. As you can guess based on the title of this article my intent is to solve this problem using Application Request Routing aka ARR, a free plug in for Windows Server IIS. ARR is an incredibly powerful utility that can be used to do many things, including acting as a reverse proxy to help route requests in a way that is completely transparent to the requestor. Combined with other features of IIS 8. For my POC, I use four virtual machines within a single Windows Azure cloud service a cloud service is simply a container that virtual machines can be placed into that provides a level of network isolation. On premises we had the availability provided by the titanium eggshell that is robust hardware, but in the cloud we need to protect ourselves from potential outages by running multiple instances configured to help minimize downtimes. To be covered by Windows Azures 9. SLA, I am required to run multiple virtual machine instances placed into an availability set. But since the Windows Azure Load Balancer doesnt support sticky sessions, I need something in the mix to deliver this functionality. The POC will consist of two layers, the ARR based Reverse Proxy layer, and the web servers. To get the Windows Azure SLA, each layer will have two virtual machines two running ARR with public endpoints for SSL traffic port 4. Requests will come in from various clients web browsers or devices and arrive at the Windows Azure Load Balancer. The load balancer will then distribute the traffic equally across our two reserve proxy virtual machines where the requests are processed by IIS and ARR and routed based on the rules we will configure to the proper applications on the web servers, each running on a unique port. Optionally, ARR will also handle the routing of requests to a specific web server, ensuring that session affinity is maintained. The following diagram illustrates the solution. The focus on this article in on how we can leverage ARR to fulfill the scenario in a way thats cloud friendly. So while the original customer scenario called for LinuxApache servers, Im going to use Windows ServerIIS for this POC. This is purely a decision of convenience since it has been a LONG time since I set up a LinuxApache web server. Additionally, while the original scenario called for multiple customers, each with their own web applicationsmodules as shown in the diagram, I just need to demonstrate the URI to specific application routing. So as youll see in later in the article, Im just going to set up a couple of web applications. Note While we can have more than two web servers, Ive limited the POC to two for the sake of simplicity. If you want to run, 3, 1. ARR web farms as well be doing later in this article. Setting up the Servers in Windows Azure. If youre used to setting up Virtual Machines in Windows Azure, this is fairly straight forward. We start by creating a cloud service and two storage accounts. The reason for the two is that I really want to try and maximize the uptime of the solution. And if all the VMs had their hard drives in a single storage account and that account experienced a sustained service interruption, my entire solution could be taken offline. NOTE The approach to use multiple storage accounts does not guarantee availability. This is a personal preference to help, even if in some small part, mitigate potential risk. You can also go so far as to define a virtual network for the machines with separate subnets for the front and back end. However, this should not be required for the solution to work as the cloud service container gives us DNS resolution within its boundaries. However, the virtual network can be used to help manage visibility and security of the different virtual machine instances. Once the storage accounts are created, I create the first of our two front end ARR servers by provisioning a new Windows Server 2.