Application Acceleration
Reply
Contributor
KStieerse
Posts: 11
Registered: ‎12-04-2010
0
Accepted Solution

Issues wth HTTP acceleration

Digging through the forum, I found a few references about HTTP acceleration and that for the most part, it should be turned off...

(for example http://forums.juniper.net/t5/Application-Acceleration/What-is-the-current-recommenation-for-HTTP-acc... )

 

Is this still true?   I'm seeing peformance issues inside our network, running 5.7.5.

 

 

 

 

 

 

Super Contributor
imirza
Posts: 88
Registered: ‎12-14-2009
0

Re: Issues wth HTTP acceleration

Hi,

 

Here is a quote from 5.7.6.0 release notes on page 6.

 

---- 

When HTTP acceleration is enabled on a WX or WXC device with WXOS 5.7 (or

later), HTTP traffic is accelerated only for remote WX and WXC devices that have

WXOS 5.6.4 (or later).

HTTP acceleration in WXOS is designed to optimize traffic within an enterprise

network (intranet). While it is possible to configure this feature to optimize all HTTP

traffic, including to and from the internet, it is not a supported configuration.

---

 

 

 

Bottom line, HTTP acceleration is supported for Intranet traffic not for Internet traffic.

 

If you are trying to accelerate internet traffic and it is an absolute MUST for you to do that then here are certain recommendations that I always tell my customers;

 

1- Try to identify at least 30-40% of webservers and assign them a separate application definition and put them under HTTP traffic class and only enable HTTP acceleration for those apps only. This will help isolate most of uncessary traffic.

2- Keep an eye on the cache objects at all time and if possible clear the cache when it is about to reach the maximam number of 25600 objects. You can use the command "she oyo cacheShow" to see how many objects are there in the disk at any given time.

3- Disable the HTTP application acceleration for the rest of the internet traffic except the defined HTTP apps.

 

What I have seen in recent times is that when you enable HTTP acceleration globally for INTERNET traffic, it works fine for only a few days and then when the cache reaches the limit, it gets into a certain state where it runs out of system resources and then it slows down every other application as well. That is why this product was never designed to accelerate INTERNET HTTP traffic.

 

Let me know if that helps.

Thanks

Iqbal Mirza

SRX Global JTAC

JNCIE-SEC#68, JNCIS-M, CCNP
_______________________________________
"Accepted Solution" = If the solutions works for you.
"Accepted Solution+Kudos" = If you really think I earned it.
Contributor
KStieerse
Posts: 11
Registered: ‎12-04-2010
0

Re: Issues wth HTTP acceleration

That makes a lot of sense, and explains why one of my boxes started throwing errors about http cache object collisions. 

 

I guess I assumed that the algorithm figured out what was "internal" based on the compression subnets or default decompressors...

 

Thanks for your help!

 

Ken

Super Contributor
imirza
Posts: 88
Registered: ‎12-14-2009
0

Re: Issues wth HTTP acceleration

Here are some of the typical errors you might be seeing in the logs;

 

I39 Trans 0x55372dc0 - HTTP object key  collision: ret = 26,URI=en.wikipedia.orghttp://en.wikipedia.org/skins-1.5/monobook/bullet.gif

 

I50 openRead-4024: URI length mismatch file=75 span=60 URI=www.tabonline.com.auhttp://www.tabonline.com.au/js/awstats_misc_tracker.js

 

I39 writeHeadersToCache (trans=0x10cb5bc8): Fail to create the file 20.20.23.193/4k.html - err=OC_OUT_OF_RESOURCE

 

 

Iqbal Mirza

SRX Global JTAC

JNCIE-SEC#68, JNCIS-M, CCNP
_______________________________________
"Accepted Solution" = If the solutions works for you.
"Accepted Solution+Kudos" = If you really think I earned it.
Copyright© 1999-2013 Juniper Networks, Inc. All rights reserved.