Hello Squid community, According to the bug report 4511 [1], Squid may transfer much useless, not requested data from uplink after specific sequence of actions. For example, slow client (access rate 128Kb/s) may begin transfer of big cacheable object (4GB). After some time, another client (access rate 1Mb/s) may begin to transfer the same object. Depending on time interval between the requests (or the volume to data cached to disk by the first transfer), after some time, transfer rate of the second client will be limited to 128Kb/s too [2]. If after some time the first client aborts the transfer, the second client's rate recovers to 1Mb/s and Squid begin to transfer the object from origin server to disk cache at maximum rate the uplink permits (let's assume 100Mb/s). If the second client also aborts the transfer after some time, it may results in much not requested data transferred from uplink. Also, if Squid doesn't finish to transfer the object to the disk cache, the object won't be cached finally. For example, if the first client aborts the transfer after downloading 100MB, Squid begins to transfer the object at rate 100Mb/s. If after 4 minutes, the second client also aborts the transfer, Squid would terminate the transfer from origin server and we get is the following statistics: Client #1 - 100MB Client #2 - 100MB + 1Mb/s / 8 bits * 240 seconds = 130MB Squid - 100MB + 100Mb/s / 8 bits * 240 seconds = 3100MB Not requested / useless data = 3100MB - (100MB + 130MB) = 2870MB In that scenario, Squid would get 2870MB useless data that would not be cached (object's size 4GB). During these 4 minutes, 'Hits as % bytes sent' counter would show extremely low value. [1] http://bugs.squid-cache.org/show_bug.cgi?id=4511 [2] http://bugs.squid-cache.org/show_bug.cgi?id=4520 ------------ So, I want to ask community to share ideas, best practice to cope with the problem. Many thank in advance! -- Garri Djavadyan <garryd@xxxxxxxxx> Comnet ISP _______________________________________________ squid-users mailing list squid-users@xxxxxxxxxxxxxxxxxxxxx http://lists.squid-cache.org/listinfo/squid-users
