Re: Cacheflow vs. Squid

Our department runs Squid and Cacheflow. Because of Cacheflow's
prefetching and proactive refreshing of pages from the most popular sites
it appears to do really well for things like www.cnn.com or www.news.com.
However, it's design is explicitly geared towards latency reduction as
opposed to bandwidth reduction. As far as I know it does not limit active
caching to off-time periods. We haven't measured the bandwidth usage
caused by Cacheflow but I strongly suspect that active caching uses a lot
of extra bandwidth.

Also, beware of using Cacheflow for anything else but standard web
browsing traffic. For example, I used it as a proxy to robot-scan the
content of popular web sites. Bad idea: Days after I completed the scans
we received angry phone calls from some of these sites. The Cacheflow box
was apparently sending an aggressive amount of refresh requests to these
scanned sites...

I guess the bottom line is that Cacheflow is great for latency reduction
of standard web traffic. On the other hand, Squid is free and will more
likely reduce your bandwidth consumption.

Carlos

On Thu, 23 Jul 1998, Fraser Campbell wrote:

    Someone has contacted me regarding a product called Cacheflow. He/they
    claim their product is vastly superior to Squid. I'd like to know if
    anyone here has any experience or comments with the product
    (http://www.cacheflow.com/).
    
    The product apparently uses "active caching". This is it "by keeping
    track of both user requests and content changes and by sending refresh
    requests based on algorithms that calculate the probability that a refresh
    will be needed. CacheFlow says this technique can boost hit rate to as
    high as 75%, compared with 30% to 40% in most cache systems."
    
    I would say that this prefetching of a page (while it may slightly
    increase response time) is going to use just as much bandwidth (possibly
    more). What does everyone think? Has anyone here used Cachflow? Sorry,
    if this is slightly off topic but I believe comparing alternative caching
    systems to be relevant.
    
    **************************************************************
    * Fraser M. Campbell - available for employment *
    * Email: fraser@greynet.net Phone: (519) 364-6115 *
    * http://www.greynet.net/fraser/ *
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Received on Thu Jul 23 1998 - 13:17:01 MDT