Hi folks, I have a setup with ICAP running a custom server alongside Squid. While testing file upload scenarios, I ran into a slow upload issue and have narrowed it down to slowness between squid and icap, especially in the request handling path. The slowness is down to extremely small packets sent by squid towards the ICAP server. These packets are a few 10s of bytes in size. This despite receiving large-sized packets from the client over the HTTPS connection. The ICAP server responds with the ACK quickly enough, so this isn't a case of small packets being generated because the server isn't quick enough to read. The debugs haven't shown any hints. It appears that there are times when Squid allocates only small buffers to read from the HTTPS connection. I see buffers of even a single byte being allocated during message processing. I am new to the Squid code, so I might be reading it all wrong. I have pasted below a sample TCP dump (incomplete) showing the behavior, resulting from a curl request. The request was generated on the same node where squid and ICAP are resident. Any hints/tips on what may be going wrong here? Appreciate any help in this matter. Thank you. Regards. Prashanth TCP dump: Note that on my setup, squid is running on port 443. Note also that the packets to-from both ports 443 and 1344 are available in this sequence. 20:53:31.479166 IP localhost.56475 > localhost.https: Flags [S], seq 2166915705, win 32792, options [mss 16396,sackOK,TS val 3300947254 ecr 0,nop,wscale 12], length 0 20:53:31.479178 IP localhost.https > localhost.56475: Flags [S.], seq 728006122, ack 2166915706, win 32768, options [mss 16396,sackOK,TS val 3300947254 ecr 3300947254,nop,wscale 12], length 0 20:53:31.479186 IP localhost.56475 > localhost.https: Flags [.], ack 1, win 9, options [nop,nop,TS val 3300947254 ecr 3300947254], length 0 20:53:31.479308 IP localhost.56475 > localhost.https: Flags [P.], seq 1:221, ack 1, win 9, options [nop,nop,TS val 3300947254 ecr 3300947254], length 220 20:53:31.479317 IP localhost.https > localhost.56475: Flags [.], ack 221, win 9, options [nop,nop,TS val 3300947254 ecr 3300947254], length 0 20:53:31.483620 IP localhost.https > localhost.56475: Flags [P.], seq 1:40, ack 221, win 9, options [nop,nop,TS val 3300947255 ecr 3300947254], length 39 20:53:31.483636 IP localhost.56475 > localhost.https: Flags [.], ack 40, win 9, options [nop,nop,TS val 3300947255 ecr 3300947255], length 0 20:53:31.497413 IP localhost.56475 > localhost.https: Flags [P.], seq 221:534, ack 40, win 9, options [nop,nop,TS val 3300947259 ecr 3300947255], length 313 20:53:31.530394 IP localhost.https > localhost.56475: Flags [P.], seq 40:3153, ack 534, win 9, options [nop,nop,TS val 3300947267 ecr 3300947259], length 3113 20:53:31.531331 IP localhost.56475 > localhost.https: Flags [P.], seq 534:1108, ack 3153, win 10, options [nop,nop,TS val 3300947267 ecr 3300947267], length 574 20:53:31.549229 IP localhost.https > localhost.56475: Flags [P.], seq 3153:3204, ack 1108, win 9, options [nop,nop,TS val 3300947272 ecr 3300947267], length 51 20:53:31.549589 IP localhost.56475 > localhost.https: Flags [P.], seq 1108:1453, ack 3204, win 10, options [nop,nop,TS val 3300947272 ecr 3300947272], length 345 20:53:31.556517 IP localhost.46489 > localhost.1344: Flags [S], seq 2773005283, win 32792, options [mss 16396,sackOK,TS val 3300947274 ecr 0,nop,wscale 12], length 0 20:53:31.556527 IP localhost.1344 > localhost.46489: Flags [S.], seq 2778855454, ack 2773005284, win 32768, options [mss 16396,sackOK,TS val 3300947274 ecr 3300947274,nop,wscale 12], length 0 20:53:31.556534 IP localhost.46489 > localhost.1344: Flags [.], ack 1, win 9, options [nop,nop,TS val 3300947274 ecr 3300947274], length 0 20:53:31.559075 IP localhost.46489 > localhost.1344: Flags [P.], seq 1:602, ack 1, win 9, options [nop,nop,TS val 3300947274 ecr 3300947274], length 601 20:53:31.559092 IP localhost.1344 > localhost.46489: Flags [.], ack 602, win 9, options [nop,nop,TS val 3300947274 ecr 3300947274], length 0 20:53:31.588467 IP localhost.https > localhost.56475: Flags [.], ack 1453, win 10, options [nop,nop,TS val 3300947282 ecr 3300947272], length 0 20:53:32.550821 IP localhost.56475 > localhost.https: Flags [.], seq 1453:17837, ack 3204, win 10, options [nop,nop,TS val 3300947522 ecr 3300947282], length 16384 20:53:32.550849 IP localhost.https > localhost.56475: Flags [.], ack 17837, win 12, options [nop,nop,TS val 3300947522 ecr 3300947522], length 0 20:53:32.550856 IP localhost.56475 > localhost.https: Flags [P.], seq 17837:17866, ack 3204, win 10, options [nop,nop,TS val 3300947522 ecr 3300947282], length 29 20:53:32.550859 IP localhost.https > localhost.56475: Flags [.], ack 17866, win 12, options [nop,nop,TS val 3300947522 ecr 3300947522], length 0 20:53:32.550916 IP localhost.56475 > localhost.https: Flags [.], seq 17866:34250, ack 3204, win 10, options [nop,nop,TS val 3300947522 ecr 3300947522], length 16384 20:53:32.550938 IP localhost.https > localhost.56475: Flags [.], ack 34250, win 10, options [nop,nop,TS val 3300947522 ecr 3300947522], length 0 20:53:32.550942 IP localhost.56475 > localhost.https: Flags [P.], seq 34250:34279, ack 3204, win 10, options [nop,nop,TS val 3300947522 ecr 3300947522], length 29 20:53:32.550946 IP localhost.https > localhost.56475: Flags [.], ack 34279, win 10, options [nop,nop,TS val 3300947522 ecr 3300947522], length 0 20:53:32.550993 IP localhost.56475 > localhost.https: Flags [.], seq 34279:50663, ack 3204, win 10, options [nop,nop,TS val 3300947522 ecr 3300947522], length 16384 20:53:32.551009 IP localhost.https > localhost.56475: Flags [.], ack 50663, win 6, options [nop,nop,TS val 3300947522 ecr 3300947522], length 0 20:53:32.551014 IP localhost.56475 > localhost.https: Flags [P.], seq 50663:50692, ack 3204, win 10, options [nop,nop,TS val 3300947522 ecr 3300947522], length 29 20:53:32.552297 IP localhost.46489 > localhost.1344: Flags [P.], seq 602:647, ack 1, win 9, options [nop,nop,TS val 3300947522 ecr 3300947274], length 45 20:53:32.552303 IP localhost.1344 > localhost.46489: Flags [.], ack 647, win 9, options [nop,nop,TS val 3300947522 ecr 3300947522], length 0 20:53:32.553609 IP localhost.46489 > localhost.1344: Flags [P.], seq 647:1644, ack 1, win 9, options [nop,nop,TS val 3300947523 ecr 3300947522], length 997 20:53:32.553615 IP localhost.1344 > localhost.46489: Flags [.], ack 1644, win 9, options [nop,nop,TS val 3300947523 ecr 3300947523], length 0 20:53:32.553983 IP localhost.1344 > localhost.46489: Flags [P.], seq 1:26, ack 1644, win 9, options [nop,nop,TS val 3300947523 ecr 3300947523], length 25 20:53:32.553988 IP localhost.46489 > localhost.1344: Flags [.], ack 26, win 9, options [nop,nop,TS val 3300947523 ecr 3300947523], length 0 20:53:32.554939 IP localhost.https > localhost.56475: Flags [.], ack 50692, win 12, options [nop,nop,TS val 3300947523 ecr 3300947522], length 0 20:53:32.554951 IP localhost.56475 > localhost.https: Flags [P.], seq 50692:62824, ack 3204, win 10, options [nop,nop,TS val 3300947523 ecr 3300947523], length 12132 20:53:32.556392 IP localhost.46489 > localhost.1344: Flags [.], seq 1644:18028, ack 26, win 9, options [nop,nop,TS val 3300947523 ecr 3300947523], length 16384 20:53:32.556415 IP localhost.46489 > localhost.1344: Flags [P.], seq 18028:21146, ack 26, win 9, options [nop,nop,TS val 3300947524 ecr 3300947523], length 3118 20:53:32.556422 IP localhost.1344 > localhost.46489: Flags [.], ack 21146, win 12, options [nop,nop,TS val 3300947524 ecr 3300947523], length 0 20:53:32.557860 IP localhost.46489 > localhost.1344: Flags [P.], seq 21146:33403, ack 26, win 9, options [nop,nop,TS val 3300947524 ecr 3300947524], length 12257 20:53:32.559221 IP localhost.46489 > localhost.1344: Flags [P.], seq 33403:33409, ack 26, win 9, options [nop,nop,TS val 3300947524 ecr 3300947524], length 6 20:53:32.559243 IP localhost.1344 > localhost.46489: Flags [.], ack 33409, win 12, options [nop,nop,TS val 3300947524 ecr 3300947524], length 0 20:53:32.560692 IP localhost.46489 > localhost.1344: Flags [.], seq 33409:49793, ack 26, win 9, options [nop,nop,TS val 3300947525 ecr 3300947524], length 16384 20:53:32.560713 IP localhost.46489 > localhost.1344: Flags [P.], seq 49793:49799, ack 26, win 9, options [nop,nop,TS val 3300947525 ecr 3300947524], length 6 20:53:32.560717 IP localhost.1344 > localhost.46489: Flags [.], ack 49799, win 12, options [nop,nop,TS val 3300947525 ecr 3300947525], length 0 20:53:32.562076 IP localhost.46489 > localhost.1344: Flags [P.], seq 49799:49806, ack 26, win 9, options [nop,nop,TS val 3300947525 ecr 3300947525], length 7 20:53:32.562333 IP localhost.https > localhost.56475: Flags [.], ack 62824, win 12, options [nop,nop,TS val 3300947525 ecr 3300947523], length 0 20:53:32.563442 IP localhost.46489 > localhost.1344: Flags [P.], seq 49806:49849, ack 26, win 9, options [nop,nop,TS val 3300947525 ecr 3300947525], length 43 20:53:32.563463 IP localhost.1344 > localhost.46489: Flags [.], ack 49849, win 12, options [nop,nop,TS val 3300947525 ecr 3300947525], length 0 20:53:32.564775 IP localhost.46489 > localhost.1344: Flags [P.], seq 49849:49856, ack 26, win 9, options [nop,nop,TS val 3300947526 ecr 3300947525], length 7 20:53:32.566070 IP localhost.46489 > localhost.1344: Flags [P.], seq 49856:49899, ack 26, win 9, options [nop,nop,TS val 3300947526 ecr 3300947525], length 43 20:53:32.566091 IP localhost.1344 > localhost.46489: Flags [.], ack 49899, win 12, options [nop,nop,TS val 3300947526 ecr 3300947526], length 0 20:53:32.567372 IP localhost.46489 > localhost.1344: Flags [P.], seq 49899:49906, ack 26, win 9, options [nop,nop,TS val 3300947526 ecr 3300947526], length 7 20:53:32.568686 IP localhost.46489 > localhost.1344: Flags [P.], seq 49906:49949, ack 26, win 9, options [nop,nop,TS val 3300947527 ecr 3300947526], length 43 20:53:32.568707 IP localhost.1344 > localhost.46489: Flags [.], ack 49949, win 12, options [nop,nop,TS val 3300947527 ecr 3300947526], length 0 20:53:32.569992 IP localhost.46489 > localhost.1344: Flags [P.], seq 49949:49956, ack 26, win 9, options [nop,nop,TS val 3300947527 ecr 3300947527], length 7 20:53:32.571285 IP localhost.46489 > localhost.1344: Flags [P.], seq 49956:49999, ack 26, win 9, options [nop,nop,TS val 3300947527 ecr 3300947527], length 43 20:53:32.571305 IP localhost.1344 > localhost.46489: Flags [.], ack 49999, win 12, options [nop,nop,TS val 3300947527 ecr 3300947527], length 0 _______________________________________________ squid-users mailing list squid-users@xxxxxxxxxxxxxxxxxxxxx http://lists.squid-cache.org/listinfo/squid-users
