ACE :Transparent Cache-SP

Unanswered Question
Mar 22nd, 2009


I have a setup for transparent caching with my SP client and as of now we are using leastconn as predictor with A2(1.3) as the version.

here are my pain points:

1. The Cache guys tell me the moment we turn normalization ON the caches cant FTP the logs to their FTP servers (the traffic/conn drops after sometime).we dont have randomization ON.

I feel its more of the cache issue or of the connection than of security as normalization will either allow or disallow but will not terminate after some time.

2. also im observing in "show stats" output , lot of "Total layer4 rejections" and some Layer7 conns, and "Total times rserver was unavailable" .. as we see probe-fails a lot when traffic peaks up thus making cache to be out-of-service , need to know when do we have these issues.does it need to have the whole farm to fail or is it for connections failing for a single cache-server?

any good links to find more on the troubleshooting aspect of ACE ?



I have this problem too.
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Gilles Dufour Tue, 03/24/2009 - 03:07


ACE has a default idle timeout of 1hour for all traffic going through.

This is true with and without normalization.

Once the connection times out, it is being removed from the connection-list.

This is where normalization makes a difference.

With normalization, a connection can only be established with a SYN.

So, when the application starts sending again, we do not allow the packets to go through.

Without normalization, any packet can be used to establish the connection, so when the server start sending data again, we re-establish the connection and allow the packets to go through.

L4 rejections occur when we can't find a server active - so the whole farm is down.


shukla1975 Tue, 03/31/2009 - 12:26

Hi Gilles,

as per TAC its a single server and not the whole farm, im kinda still looking for confirmation as the whole farm failing will be catastrophic....

for normalization, for example:

my cache team says , the FTP starts with TCP and then for data transfer uses UDP, in this case ACE would drop the packet ?

Can we configure application specific normalization parameters ?

thanks in advance.



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