3com Webcache 1000 (3C16115) User Manual

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HAPTER
 13: P
ROBLEM
 S
OLVING
Solving Webcache 
Performance 
Problems
The performance of the Webcache is poor
Check:
Whether any of the cache storage devices have failed. Examine the 
front panel LEDs to ensure there are no faults found. If there are, 
contact 3Com support personnel. As long as there is at least one 
working cache storage device, the Webcache will operate as a cache, 
but the failure of a cache storage device will degrade the performance 
of the Webcache. If all cache storage devices have failed, the 
Webcache will pass all requests through to the Web without 
performing any caching.
The Caching Performance graphs in the Device View -> Performance 
folder. Specifically check the Hit and Miss Rate graph. If the hit rate 
percentage is low, save the system log onto another device in your 
network. Then use a utility like Webtrends to analyze your web traffic 
and see if a higher hit rate is expected.
Run a network performance test between your client machines and 
your Webcache using the Ping command. Check that the response 
time is reasonable.
Analyze your network to look for network errors.
If you are using Proxy Auto Configuration (PAC) files to configure 
browsers, try setting the browser settings manually to avoid the 
overhead of PAC files.
If you are using the Web Proxy Auto-Discovery (WPAD) protocol to 
configure the browsers on client machines, try setting the browser 
settings manually to avoid the overhead of the WPAD protocol.
The Webcache Domain Name Server configuration to check that it can 
access the DNS server.
No Web sites can be accessed using the Webcache
Check the Webcache DNS and Default Router settings, and try to ping 
these addresses from the Webcache.
Alternatively, if the Webcache is operating in transparent mode, it will not 
service Web requests from browsers on client machines that are using the 
Webcache as a proxy server. None of those client machines will be able to 
access the Web. You must configure the browsers to use another proxy 
server and bypass the Webcache, or configure the browsers so that they 
are not operating in proxy mode.