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Websites vs Webroles vs VMs + Load Balancing. RRS feed

  • Question

  • I currently have 10 Websites that run on 2 physical machines behind a load balancer.  I understand how the database component would migrate to Azure, but I'm not entirely clear on how the websites would migrate and what my options are.

    I could buy 2 VMs and configure/manage them myself.  I would RDP in and deploy my existing code.  Are those auto-load-balanced?  Or is there an additional Load Balancer component that I would need to buy that I'm not seeing?

    It appears that each "Reserved Website" grants me 100 websites on each.  If I were to buy 4 of them, install my 10 sites on each of the 4, are those auto-load-balanced?  Does deploying to the Reserved Website require any modification to my code?

    If I want to estimate cost for the WebRoles, do I need 10 of them since I have 10 websites?  What would it mean to have those load-balanced?  This definitely requires code changes, yes?

    I called the Sales line and was able to get answers to some of my questions, but I was not able to get clarity on these more detailed issues.

    • Moved by Arwind - MSFTModerator Wednesday, June 20, 2012 7:35 AM (From:Windows Azure Purchasing, Pricing & Billing)
    Tuesday, June 19, 2012 9:32 PM

Answers

  • Hi Jacob,

    VMs are load balanced using Azure core LB solution, but the code running inside, in your case would have to implement its' own LB solution for the application that VM is hosting. In your case that would be IIS. IIS does have an OOB software load balancer ARR that you can use to configure this scenario.

    If you choose to go with Windows Azure Websites, with "reserved" instance you will get 100 sites running on the dedicated VM of your size. You really dont need to buy 4 such instances under different sunbscriptions, You can actually buy one and then scale up, by increasing instances to 3 within the site configuration. This will all be load balanced for you automatically. Generally, deploying to Windows Azure Webistes does not require code changes, unless your application is doing certain things that will need an administrative level rights etc. You need to manage session state outside of aplication if you are going to scale out.

    Webrole needs code investments and yes you will have to buy atleast 10 of those and 20 to be have 100% HA.

    Depending on what kind of applications these are, your choice will vary. Windows Azure Websites is most easyliy portable and cheap solution, but it's currently in CTP without any SLA.

    HTH

    AJ


    Apurva Joshi, This posting is provided "AS IS" with no warranties, and confers no rights.

    • Proposed as answer by Apurva Joshi (AJ) Wednesday, June 20, 2012 9:30 PM
    • Marked as answer by Jacob.G Wednesday, June 20, 2012 10:12 PM
    Wednesday, June 20, 2012 3:55 PM

All replies

  • Hi Jacob,

    VMs are load balanced using Azure core LB solution, but the code running inside, in your case would have to implement its' own LB solution for the application that VM is hosting. In your case that would be IIS. IIS does have an OOB software load balancer ARR that you can use to configure this scenario.

    If you choose to go with Windows Azure Websites, with "reserved" instance you will get 100 sites running on the dedicated VM of your size. You really dont need to buy 4 such instances under different sunbscriptions, You can actually buy one and then scale up, by increasing instances to 3 within the site configuration. This will all be load balanced for you automatically. Generally, deploying to Windows Azure Webistes does not require code changes, unless your application is doing certain things that will need an administrative level rights etc. You need to manage session state outside of aplication if you are going to scale out.

    Webrole needs code investments and yes you will have to buy atleast 10 of those and 20 to be have 100% HA.

    Depending on what kind of applications these are, your choice will vary. Windows Azure Websites is most easyliy portable and cheap solution, but it's currently in CTP without any SLA.

    HTH

    AJ


    Apurva Joshi, This posting is provided "AS IS" with no warranties, and confers no rights.

    • Proposed as answer by Apurva Joshi (AJ) Wednesday, June 20, 2012 9:30 PM
    • Marked as answer by Jacob.G Wednesday, June 20, 2012 10:12 PM
    Wednesday, June 20, 2012 3:55 PM
  • Can we have more detail regarding load balancing on Azure Web Sites.

    There is a whole section discussing load balancing using Windows Azure Traffic Manager where developers can choose from three load balancing methods: Performance, Failover, or Round Robin.

    You mention it is automatic on Azure Web Sites with multiple instances, but which method is used out of Performance, Failover, or Round Robin?

    Saturday, August 18, 2012 11:22 AM
  • It's software LB solution using Microsoft ARR (Application Request Routing).

    http://learn.iis.net/page.aspx/486/http-load-balancing-using-application-request-routing/

    It mainly uses round robin to assign the requests to your workers.

    HTH

    AJ


    Apurva Joshi, This posting is provided "AS IS" with no warranties, and confers no rights.

    Tuesday, August 21, 2012 5:05 PM
  • Is there a way to get Websites to load balance based on performance / geography?

    Robert Levy

    Friday, January 10, 2014 4:11 AM
  • Hi Apoorva,

    A simple question on web apps load balancing. You have said it is automatically done. Where should I point my DNS? Let us assume I have 3 web app instances are running within a resource group. How the load will be distributed from DNS? DO I need to configure ARR on a separate server / load balancer...I did NOT find any material on this? please help

    best regards

    Raj

    Monday, November 23, 2015 5:46 PM
  • You map your DNS to the hostname of the Web App. If you web app name is abc.azurewebsites.net which has custom domain of www.abc.com then you map your DNS as www.abc.com --> abc.azurewebsites.net

    See this article for more details on DNS mapping.

    https://azure.microsoft.com/en-us/documentation/articles/web-sites-custom-domain-name/

    DNS will send traffic to abc.azurewebsites.net which will be offloaded on our frontend roles, which has knowledge of 3 instances where your web app is running and it will load balance them automatically for you. You do not need to configure ARR or worry about anything, we take care of that for you.

    HTH

    AJ


    Apurva Joshi, This posting is provided "AS IS" with no warranties, and confers no rights.

    Monday, November 23, 2015 6:58 PM