Layer7 API Management

  • 1.  API Gateway load balancing across servers

    Posted Oct 06, 2016 10:27 AM

    Hi All,

    I would like to know if API gateway can load balance across servers serving up an API it is protecting, or if it needs to integrate with VIPs for load balancing / failover?

     

    Thanks in advance.



  • 2.  Re: API Gateway load balancing across servers

    Broadcom Employee
    Posted Oct 06, 2016 11:25 AM

    Good morning,

     

    The HTTP Routing assertion has several load balancer/fail over strategies such as round robin, order sticky, etc ( Route via HTTP(S) Assertion - CA API Gateway - 9.1 - CA Technologies Documentation ) which can also be used in conjunction with Routing Strategies (Working With Dynamic Routing - CA API Gateway - 9.1 - CA Technologies Documentation ).

     

    The Gateway can also be used with a load balancer VIP that manages available back-end systems.

     

    Sincerely,

     

    Stephen Hughes

    Director, CA Support



  • 3.  Re: API Gateway load balancing across servers

    Posted Oct 07, 2016 05:45 PM

    Hi Steve,

     

    My Requirement is for API Gateway to act as a proxy to a service deployed on 2 back end servers, TEST A and TEST B.

    API Gateway should balance send the request equally across both servers and send to Test B only if Test A is down and vice versa.

     

    I am following the document you mentioned here. I tried to create a routing strategy, I selected on create New ROute, I gave it a name and clicked 'ADD' for route properties. I am confused as to what needs to go here, appreciate assistance. It may be very intuitive and self explanatory but I am stuck as the document says just  '

    1. Configure the route properties.'

    Ravichandran, I m not trying to hijack your thread , just trying to keep related info in one place. Please let me know if you want me to start another thread.



  • 4.  Re: API Gateway load balancing across servers
    Best Answer

    Posted Oct 12, 2016 10:39 AM

    Hey Sam,

     

    You should be able to do this in the Route via HTTP Assertion itself. 

     

    Here's an example of what a route could look like

     

     

    it this case, we have multiple urls to route to and we are using a 'Round-Robin' failover strategy...

     

    looking at the doc, here are the details of 'Round-Robin'

     

     

    hope this helps!



  • 5.  Re: API Gateway load balancing across servers

    Posted Oct 12, 2016 03:42 PM

    Thank You , Sir. Much appreciated. Will test and let you know.

     

    I have been playing with that assertion for a couple of days but could not find that screen,



  • 6.  Re: API Gateway load balancing across servers

    Posted Mar 08, 2018 11:41 PM

    I know it's the old thread but still trying my luck out. My questions is, how does the API gateway knows if the end application is does? Does it do the polling like a Industry Standard load balancer or it does it in the real time when the transaction comes?

     

    Question appear trivial but in our case we are trying to remove the load balancer between APIG and backend application instances. So all I want to know how APIG handles this scenario.

     

    A typical LB would do a health check to determine if the service is available or not. This happens in background and not at the time transactions comes in. We are not worried that API gateway would do the fail over but rather it would try to direct every alternate request to the unavailable server and then redirect it to the next one active. Hope I am able to clearly articulate my query.

    Thanks,

    Varun



  • 7.  Re: API Gateway load balancing across servers

    Broadcom Employee
    Posted Mar 08, 2018 11:49 PM

    Varun,

     

    We don't do polling by default within the gateway but you could look to use Dynamic Routing (Working With Dynamic Routing - CA API Gateway - 9.2 - CA Technologies Documentation) in combination with using Scheduled tasks that could ping the back end at periodic intervals and update the information associated with Dynamic Routing.

     

    Sincerely,

     

    Stephen Hughes

    Director, CA Support



  • 8.  Re: API Gateway load balancing across servers

    Broadcom Employee
    Posted Nov 05, 2018 02:09 PM

    thanks for this input stephen , it was very helpful for s similar use case for me. 



  • 9.  Re: API Gateway load balancing across servers

    Posted Mar 09, 2018 12:47 AM

    Thank you for your help. Really useful information, addresses my query.