Re: cache_swap size

Pattara Kiatisevi writes:

>Dear guys,
>
>We are from NECTEC, Thailand running 2 cache servers, cache1 and
>cache2.nectec.or.th . Although we tell our downstream nodes to point to us
>both cache1 and cache2 but it seems that cache1 now doing much work than
>cache2. Then I try new method by separating domain,
>
>At cache1:
>
>cache_host cache2.nectec.or.th parent 8080 3130 proxy-only
>cache_host_domain cache2.nectec.or.th com
>
>At cache2:
>
>cache_host cache1.nectec.or.th parent 8080 3130 proxy-only
>cache_host_domain cache1.nectec.or.th !.com

This is a reasonable thing to do. In our experience, the COM
domain makes up 60% or more of all requests, so its not a
perfect balance, but its pretty good. Your percentage might
be closer to 50%.

>I'm not sure if this is a good way to this, will the data in both cache is
>duplicated? And I wonder about cache size, do we have a formula to

Since you use 'proxy-only' there will not be very much duplication,
but there could be some.

>calculate the cache size. Cache1 is Alpha2x5/466MHz 512MB without
>1,500,000-2,000,000 request/day and 25 GB of cache space causes it to have
>a very slow response time. Now I just restart the cache space and both of
>them works fine (fast).

If you have bad response times, you should decrease your cache size a
little or find some other way to reduce memory usage. Going from 25 GB
to, say 23 GB will probably have very little effect on your hit ratio.

Duane W.
Received on Thu Jul 02 1998 - 00:05:23 MDT