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?
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?
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
My refresh_pattern(s) look like this:
refresh_pattern -i \.jpe?g$ 1440 50% 10080 reload-into-ims refresh_pattern -i \.tiff?$ 1440 50% 10080 reload-into-ims refresh_pattern -i \.gif$ 1440 50% 10080 ignore-reload refresh_pattern -i \.png$ 1440 50% 10080 reload-into-ims refresh_pattern -i \.bmp$ 1440 50% 10080 reload-into-ims refresh_pattern -i \.p(n|b|g|p)m$ 1440 50% 10080 reload-into-ims refresh_pattern . 30 50% 10080
Example TCP_REFRESH_HITs:
1113779628.851 240 192.168.37.165 TCP_REFRESH_HIT/200 648 GET http://www.google.com/nav_current.gif - DIRECT/www.google.com text/html 1113779628.876 257 192.168.37.165 TCP_REFRESH_HIT/200 1306 GET http://www.google.com/nav_first.gif - DIRECT/www.google.com text/html 1113779628.902 284 192.168.37.165 TCP_REFRESH_HIT/200 645 GET http://www.google.com/nav_page.gif - DIRECT/www.google.com text/html 1113779628.924 259 192.168.37.165 TCP_REFRESH_HIT/200 1787 GET http://www.google.com/nav_next.gif - DIRECT/www.google.com text/html 1113779629.092 241 192.168.37.165 TCP_REFRESH_HIT/200 2905 GET http://www.google.com/images/gds1.gif - DIRECT/www.google.com text/html 1113777949.633 323 192.168.37.58 TCP_REFRESH_HIT/304 165 GET http://www.bankofamerica.com/global/mvc_objects/stylesheet/masthead.css - DIRECT/www.bankofamerica.com - 1113777949.681 356 192.168.37.58 TCP_REFRESH_HIT/304 165 GET http://www.bankofamerica.com/global/hs_home/signin.js - DIRECT/www.bankofamerica.com - 1113777950.138 185 192.168.37.58 TCP_REFRESH_HIT/304 165 GET http://www.bankofamerica.com/global/js/fontsize.js - DIRECT/www.bankofamerica.com - 1113777950.466 200 192.168.37.58 TCP_REFRESH_HIT/304 165 GET http://www.bankofamerica.com/x.gif - DIRECT/www.bankofamerica.com - 1113777950.470 197 192.168.37.58 TCP_REFRESH_HIT/304 165 GET http://www.bankofamerica.com/global/mvc_objects/images/mhd_reg_logo.gif - D
