Forum Discussion

Puli's avatar
Icon for Nimbostratus rankNimbostratus
Dec 13, 2011

performance and impact of STREAM Expression

We created a new iRule, which will replace links from one doamin to another in page content.


Below is the iRule



if {[HTTP::header vaule Content-Type] contains "text"}{


STREAM::expression {@http://doaminA@http://doaminB@}








Need clarification on performance.


1) What is the performance impact of using STREAM profile, i understand bigip will look at page content but is it detrimental for the bigip for a website that gets 2 pageviews per seconds. Does it impact bigip ?



2) Does bigip consume more memory with STREAM processing ?


What the impact on memory utilization.


The size of the pages mostly ranges from 1-1.5MB



Would appreciate if anyone is using in production with lot more pageviews.



Appreciate feedback and comments.






3 Replies

  • Puli's avatar
    Icon for Nimbostratus rankNimbostratus
    Any thoughts ? appreciate any thoughts and feedback.


    Our BigIP LTM admin is concerned about performance using the STREAM profile.


    Wanted if other people have used it sucessfully without issues.
  • Hi Puli,

    I haven't done or seen any stream specific performance testing. I've implemented it at a number of customer sites though. I wouldn't add the iRule to a unit which is already at 80 or 90%. But I'd be confident in using it on a lower unit with lower utilization.

    Make sure to disable the stream filter in HTTP_REQUEST in your rule though:

    when HTTP_REQUEST {
        Disable the stream filter by default on all requests
    when HTTP_RESPONSE {
        Check if response is text
       if {[HTTP::header value Content-Type] contains "text"}{
           Set expression to find/replace and enable the stream filter
          STREAM::expression {@http://domainA@http://domainB@}

    If you want to get estimates before putting it into production, you could enable timing on the iRule and test it on a test virtual server or test LTM:

  • Puli's avatar
    Icon for Nimbostratus rankNimbostratus
    thanks very much Aaron. appreciate your time.