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Robert_47833's avatar
Robert_47833
Icon for Altostratus rankAltostratus
Jul 22, 2015

disable irule process for the request not for the whole tcp connection

hi ,Iurle I need to stop irule process for the exact http request ,not for the whole tcp connection ,how to achieve this?  
application delivery
design
LTM
  • Kiozs_131042's avatar
    Kiozs_131042
    Jul 26, 2015

    Understood this topic is discussing some race conditions applied on iRule http events;

    client 1 --> http request1 --> F5 --> http request1 --> server
client 1 --> http request2 --> F5 --> http request2 --> server
client 1 --> http request3 --> F5 --> http request3 --> server
client 1 <-- http request1 <-- F5 <-- http response1 <-- server
client 1 <-- http request2 <-- F5 <-- http response2 <-- server
client 1 <-- http request3 <-- F5 <-- http response3 <-- server

    From LTM perspective, LTM will not process the subsequent request (but rather put it on the request queue instead)until first response is back from backend pool memeber.

    Even pipelining is enabled on client side and multiple requests come in at same time, LTM will still serialize them and process them according to the sequence (FIFO).

    So in our case, variable has been set in request 1 will not be messed up even request 2 comes in earlier than response 1.

Kevin_Stewart's avatar
Kevin_Stewart
Icon for Employee rankEmployee
Jul 24, 2015

Yes. iRules variables are TCP connection scoped - meaning they exist for the life of a discreet TCP connection. If you create a variable in one event you can manipulate it in another if their both in the same TCP connection. I'd also point out here that when you add multiple iRules to a VIP, and those iRules contain the same events (ex. HTTP_REQUEST), these events are compiled into one event. That's why the order of the iRules (an option in the GUI in 11.x and a "priority" option in the event declaration otherwise) is so important.