> -----Original Message----- > From: Scott Presnell [mailto:srp@xxxxxxxxxxxx] > Sent: Monday, April 18, 2005 8:40 AM > To: squid-users > Subject: [squid-users] Help understanding calamaris/squid output > > > HI Folks, > I'm running Squid Cache: Version 2.5.STABLE7 under NetBSD 2.0 > and I'm using calamaris to try and track performance. Calamaris seems > to be telling me that my TCP_REFRESH_HIT speed performance is poor; actually > lower than my MISS performance. I have some questions: > > 1) Why would this be true? Overhead of the IMS test + the actual request? > local disk performace issues? What can I do to further interrogate and increase > the performance of this kind of request/response? It's not... TCP_REFRESH_HITs are taking 0.2 seconds to complete. Your fastest MISS (TCP_CLIENT_REFRESH_MISS) is taking twice as long. If you are looking at the kB/sec speed, then you must realize that small transfers (as a TCP_REFRESH_HIT will be) suffer from TCPs slow start. Nothing you can do about that. > > 2) Given the definition of TCP_REFRESH_HIT: > > The requested object was cached but STALE. The IMS query for the object resulted in "304 not modified". > > ... then what is the difference between TCP_REFRESH_HIT/200 and TCP_REFRESH_HIT/304? TCP_REFRESH_HIT/200 = Object was cached, and not marked as stale. TCP_REFRESH_HIT/304 = Object was cached, marked as stale, but the request to the origin server returned "304 Not Modified". > > Thanks for any help. > > - Scott > > # Incoming TCP-requests by status > status request % sec/req Byte % kB/sec > ------------------------------ --------- ------ ------- -------- ------ ------- > HIT 11599 54.81 0.12 11108299 6.26 7.95 > TCP_REFRESH_HIT 6572 31.06 0.20 6582553 3.71 4.94 > TCP_MEM_HIT 2929 13.84 0.01 2529904 1.43 79.90 > TCP_IMS_HIT 1136 5.37 0.01 262521 0.15 18.61 > TCP_HIT 942 4.45 0.02 1706470 0.96 92.35 > TCP_NEGATIVE_HIT 20 0.09 0.01 26851 0.02 141.74 > MISS 7279 34.40 1.53 156276K 90.15 14.00 > TCP_MISS 6579 31.09 1.64 149822K 86.43 13.89 > TCP_CLIENT_REFRESH_MISS 462 2.18 0.40 5698990 3.21 29.81 > TCP_REFRESH_MISS 238 1.12 0.80 909725 0.51 4.64 > ERROR 2283 10.79 0.72 6372629 3.59 3.78 > TCP_MISS 1718 8.12 0.96 5551109 3.13 3.30 > TCP_DENIED 564 2.67 0.00 819910 0.46 652.03 > TCP_REFRESH_MISS 1 0.00 0.05 1610 0.00 32.09 > ------------------------------ --------- ------ ------- -------- ------ ------- > Sum 21161 100.00 0.67 173347K 100.00 12.23 > Chris
