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dragonflymr's avatar
dragonflymr
Icon for Cirrostratus rankCirrostratus
Feb 12, 2015

Fastest LB, OneConnect and...

Hi,

 

I am a bit lost when it comes to terms used for Fastest LB description. Basically it described as based on outstanding L7 requests. But what exactly is that mean? If we talking about HTTP L7 request is equal to HTTP request? What in case of other L7 protocols like FTP or SMTP etc.?

 

The other are I am not sure about is how it relates to TCP connections (L4). As far as I understand when no OneConnection profile is used (at least for HTTP) LB decision is made once for each TCP connection. In case of HTTP/1.1 one TCP connection can contain many HTTP request (and replies) so how Fastest will handle such situation? It will increase outstanding counter only when first HTTP request is send over given TCP connection or it will be increasing counter for each HTTP request send over this TCP connection?

 

What about situation when OneConnect is used? According to docs in this case LB decision can be made for each HTTP request instead of each TCP connection. Will then Fastest count each request even if on the client side there is just one TCP connection transporting many HTTP requests?

 

Piotr

 

application delivery
design
LTM
performance
TMOS

10 Replies

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  • Brad_Parker_139's avatar
    Brad_Parker_139
    Icon for Nacreous rankNacreous
    Feb 12, 2015

    Yes, you should expect that it will count each request when you have a OneConnect profile in use because that decision is being made before a tcp connection is made to the node to send such request.

     

    • Brad_Parker_139's avatar
      Brad_Parker_139
      Icon for Nacreous rankNacreous
      Feb 12, 2015
      This is why it is always recommended to use OneConnect if you are planning on using L7 persistence type such as cookie.
    • dragonflymr's avatar
      dragonflymr
      Icon for Cirrostratus rankCirrostratus
      Feb 12, 2015
      It's recommended because over OneConnect request with different cookies can be directed to different members on request by request basis? So to summarize, when Fastest is used: 1. Without OneConnect outstanding counter is increased when first request is send over TCP connection, following request over the same connection are ignored. Then it means that counter is decreased when last reply is send and TCP connection is closed - so actually it's more like TCP connection counter not request counter - Am I right? 2. With OneConnect counter is increased for each request transmitted over TCP connection and decreased wen each response is received meaning we can have one TCP connection to the server but 5 outstanding request? Piotr
    • Brad_Parker_139's avatar
      Brad_Parker_139
      Icon for Nacreous rankNacreous
      Feb 12, 2015
      Recommend because only the first request would be guaranteed to persist properly, it would be possible the persistence could be ignored for subsequent requests. 1. I believe the behavior will load balance each request not each connection, that's why it requires the L7 profile(HTTP). It will default back to least connection behavior if you don't have that L7 profile. 2. Yes. Summation, OneConnect shouldn't come into play with this load balancing method. I didn't give enough consideration to all your question in my original response.
  • Brad_Parker's avatar
    Brad_Parker
    Icon for Cirrus rankCirrus
    Feb 12, 2015

    Yes, you should expect that it will count each request when you have a OneConnect profile in use because that decision is being made before a tcp connection is made to the node to send such request.

     

    • Brad_Parker's avatar
      Brad_Parker
      Icon for Cirrus rankCirrus
      Feb 12, 2015
      This is why it is always recommended to use OneConnect if you are planning on using L7 persistence type such as cookie.
    • dragonflymr's avatar
      dragonflymr
      Icon for Cirrostratus rankCirrostratus
      Feb 12, 2015
      It's recommended because over OneConnect request with different cookies can be directed to different members on request by request basis? So to summarize, when Fastest is used: 1. Without OneConnect outstanding counter is increased when first request is send over TCP connection, following request over the same connection are ignored. Then it means that counter is decreased when last reply is send and TCP connection is closed - so actually it's more like TCP connection counter not request counter - Am I right? 2. With OneConnect counter is increased for each request transmitted over TCP connection and decreased wen each response is received meaning we can have one TCP connection to the server but 5 outstanding request? Piotr
    • Brad_Parker's avatar
      Brad_Parker
      Icon for Cirrus rankCirrus
      Feb 12, 2015
      Recommend because only the first request would be guaranteed to persist properly, it would be possible the persistence could be ignored for subsequent requests. 1. I believe the behavior will load balance each request not each connection, that's why it requires the L7 profile(HTTP). It will default back to least connection behavior if you don't have that L7 profile. 2. Yes. Summation, OneConnect shouldn't come into play with this load balancing method. I didn't give enough consideration to all your question in my original response.