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aelred_1927's avatar
aelred_1927
Icon for Nimbostratus rankNimbostratus
May 28, 2009

Sticky CPU utilization (debunking info needed)

First, sorry if this is a bit off-topic.

 

 

We are having a raging debate in a large enterprise environment regarding use of Cisco's ACE product vs. F5 BigIPs for a new GTM/GLB function.

 

 

Two of the senior architecture wonks have made a statement that once sticky is turned on, only one CPU can pick up the load, which reduces throughput of the box. This is based on a presentation several years ago by some Cisco product engineers.

 

 

Does anybody have any knowledge/history of this? I've used BigIP at two large institutions previously and never run into this, but I don't have access to product or lab right now to disprove the veracity of the statement.

 

 

Any help is appreciated.

 

 

TIA,

 

 

-s
config
design

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  • dennypayne's avatar
    dennypayne
    Icon for Employee rankEmployee
    May 28, 2009
    Hi,

    According to SOL 7751 (Click here), it depends on what type of persistence is used. Specifically: 

      
 If a virtual server references any of the following BIG-IP system features, CMP is disabled for that virtual server and handled by TMM0 only:  
 * A rate class  
 * iRules global variables  
 * A persistence profile or iRule using a method other than cookie persistence  
 Note: Cookie persistence methods are exempt from CMP demotion since they are the only methods which do not store information in 
  memory; instead, they write persistence information to a cookie that is then read each time the client sends the cookie back in a  
  subsequent request.

    So as long as you use cookie persistence, CMP will remain enabled.

    Denny
  • L4L7_53191's avatar
    L4L7_53191
    Icon for Nimbostratus rankNimbostratus
    May 30, 2009
    The version 10 release notes contain:

     

     

    "Also, the CMP feature now remains enabled when running BIG-IP system modules such as Application Security Manager and WebAccelerator™, and when most features such as persistence and iRule read-only global variables are configured on a virtual server."

     

     

    ...although this doesn't specify the specific persistence types involved.

     

     

    -Matt