Re: [squid-users] Interpreting of logfiles

Squid's measurement of client speeds is a bit optimistic ;-)

Details: Squid measures the time it takes from receiving the request to write
the full reply to the client TCP connection. It does not actually wait for
TCP to finalize the delivery of the data to the end user. With a TCP transmit
buffer size of 64K (default on Linux) this can give almost infinite speeds on
cache hits.

Regards
Henrik

Boosten, Peter wrote:
> Hi Guys (m/f),
>
> Yesterday I asked a question about measuring downloadspeeds, while dividing
> column 5 (size) from access.log by column 2 (elapsed time).
>
> Henrik mentioned that some clients don't close their connection fully and
> therefor some logentries had a second extra added.
>
> How about this one (wrapped):
>
> 1029400340.528 4 172.31.142.226 TCP_HIT/200 32758 GET http://orbit-
> net.nesdis.noaa.gov/goes/aviation/rawimage/loops/gifs/atl_wv/19.gif -
> NONE/- image/gif
>
> Here a file (32758 bytes) is serviced from cache in 4 ms, that would be a
> connectionspeed of 7997.59 Kbytes/sec., which is not possible, because the
> client is located on the other side of a T1, which is 1.5 Mbit!
>
> Any explaination possible for this?
>
> Peter
>
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Received on Fri Aug 16 2002 - 08:21:21 MDT