Problem after migration ACE20 A2(3.3) to ACE30 A5(1.2)

[Jakub Begziak]

Hello,

After migration some of apllications didn't work correctly. I troubleshooted the problem with the length of http header. The question is why the problem occur after migration? As I checked the default value of header-maxparse-length didn’t change. It is also strange because some of applications, which didn’t work correctly on new devices, hasn’t used default value on ACE20. I mean if application used http parameter map with header-maxparse-length 8000 on ACE20, I have to increase it to 16000 on ACE30.

Important information - the problem occurs only for clients which use firefox web-browser. Other browsers work fine with old values.

[jlamousn]

Hello Jakub,

The change of behavior may be due to persistence rebalance which is enabled by default on the ACE30 but wasn't on ACE20. If you didn't have persistence rebalance specifically enabled on the ACE20, then the ACE20 was only looking at the first http request in any given tcp connection and we would stop parsing http after the first request. With ACE30 by default we parse every single http request by default so maybe one of those subsequent http request had large http headers which would have been ignored by the ACE20.

You can engage the Cisco TAC for further troubleshooting on this, we would need packet traces and further in depth troubleshooting to diagnose the root cause of the issue.

Joel Lamousnery
CCIE R&S - 36768
Engineer, Customer Support
Technical Services

[Jakub Begziak]

Hello,

I forgot to remind, that in ACE20 I had configured persistent-rebalance in http parameter-map.

I looked at forum and I found such discussion:

https://supportforums.cisco.com/docs/DOC-24752#comment-12787

Clients who experience the problem said that they had problem with sending a lot of data to application. My solution is a little bit different as Ajay suggest but it works. The question is why only firefox clients are impacted.