weblatency.d revision 1.1.1.1
1 #!/usr/sbin/dtrace -s 2 /* 3 * weblatency.d - website latency statistics. 4 * Written using DTrace (Solaris 10 3/05). 5 * 6 * $Id: weblatency.d,v 1.1.1.1 2015/09/30 22:01:06 christos Exp $ 7 * 8 * USAGE: weblatency.d # hit Ctrl-C to end sample 9 * 10 * See the code below for the "BROWSER" variable, which sets the browser 11 * to trace (currently set to "mozilla-bin"). 12 * 13 * This is written as an experimental tool, and may not work at all with 14 * your browser. 15 * 16 * FIELDS: 17 * HOST Hostname from URL 18 * NUM Number of GETs 19 * AVGTIME(ms) Average time for response, ms 20 * MAXTIME(ms) Maximum time for response, ms 21 * 22 * NOTE: 23 * 24 * The latency measured here is from the browser sending the GET 25 * request to when the browser begins to recieve the response. It 26 * is an overall response time for the client, and encompasses 27 * connection speed delays, DNS lookups, proxy delays, and web server 28 * response time. 29 * 30 * IDEA: Bryan Cantrill (who wrote an elegant version for Sol 10 update 1) 31 * 32 * COPYRIGHT: Copyright (c) 2005, 2006 Brendan Gregg. 33 * 34 * CDDL HEADER START 35 * 36 * The contents of this file are subject to the terms of the 37 * Common Development and Distribution License, Version 1.0 only 38 * (the "License"). You may not use this file except in compliance 39 * with the License. 40 * 41 * You can obtain a copy of the license at Docs/cddl1.txt 42 * or http://www.opensolaris.org/os/licensing. 43 * See the License for the specific language governing permissions 44 * and limitations under the License. 45 * 46 * CDDL HEADER END 47 * 48 * ToDo: 49 * Check write fd for socket, not file. 50 * 51 * 30-Nov-2005 Brendan Gregg Created this. 52 * 20-Apr-2006 " " Last update. 53 */ 54 55 #pragma D option quiet 56 57 /* browser's execname */ 58 inline string BROWSER = "mozilla-bin"; 59 60 /* maximum expected hostname length + "GET http://" */ 61 inline int MAX_REQ = 64; 62 63 dtrace:::BEGIN 64 { 65 printf("Tracing... Hit Ctrl-C to end.\n"); 66 } 67 68 /* 69 * Trace brower request 70 * 71 * This is achieved by matching writes for the browser's execname that 72 * start with "GET", and then timing from the return of the write to 73 * the return of the next read in the same thread. Various stateful flags 74 * are used: self->fd, self->read. 75 * 76 * For performance reasons, I'd like to only process writes that follow a 77 * connect(), however this approach fails to process keepalives. 78 */ 79 syscall::write:entry 80 /execname == BROWSER/ 81 { 82 self->buf = arg1; 83 self->fd = arg0 + 1; 84 self->nam = ""; 85 } 86 87 syscall::write:return 88 /self->fd/ 89 { 90 this->str = (char *)copyin(self->buf, MAX_REQ); 91 this->str[4] = '\0'; 92 self->fd = stringof(this->str) == "GET " ? self->fd : 0; 93 } 94 95 syscall::write:return 96 /self->fd/ 97 { 98 /* fetch browser request */ 99 this->str = (char *)copyin(self->buf, MAX_REQ); 100 this->str[MAX_REQ] = '\0'; 101 102 /* 103 * This unrolled loop strips down a URL to it's hostname. 104 * We ought to use strtok(), but it's not available on Sol 10 3/05, 105 * so instead I used dirname(). It's not pretty - it's done so that 106 * this works on all Sol 10 versions. 107 */ 108 self->req = stringof(this->str); 109 self->nam = strlen(self->req) > 15 ? self->req : self->nam; 110 self->req = dirname(self->req); 111 self->nam = strlen(self->req) > 15 ? self->req : self->nam; 112 self->req = dirname(self->req); 113 self->nam = strlen(self->req) > 15 ? self->req : self->nam; 114 self->req = dirname(self->req); 115 self->nam = strlen(self->req) > 15 ? self->req : self->nam; 116 self->req = dirname(self->req); 117 self->nam = strlen(self->req) > 15 ? self->req : self->nam; 118 self->req = dirname(self->req); 119 self->nam = strlen(self->req) > 15 ? self->req : self->nam; 120 self->req = dirname(self->req); 121 self->nam = strlen(self->req) > 15 ? self->req : self->nam; 122 self->req = dirname(self->req); 123 self->nam = strlen(self->req) > 15 ? self->req : self->nam; 124 self->req = dirname(self->req); 125 self->nam = strlen(self->req) > 15 ? self->req : self->nam; 126 self->nam = basename(self->nam); 127 128 /* start the timer */ 129 start[pid, self->fd - 1] = timestamp; 130 host[pid, self->fd - 1] = self->nam; 131 self->buf = 0; 132 self->fd = 0; 133 self->req = 0; 134 self->nam = 0; 135 } 136 137 /* this one wasn't a GET */ 138 syscall::write:return 139 /self->buf/ 140 { 141 self->buf = 0; 142 self->fd = 0; 143 } 144 145 syscall::read:entry 146 /execname == BROWSER && start[pid, arg0]/ 147 { 148 self->fd = arg0 + 1; 149 } 150 151 /* 152 * Record host details 153 */ 154 syscall::read:return 155 /self->fd/ 156 { 157 /* fetch details */ 158 self->host = stringof(host[pid, self->fd - 1]); 159 this->start = start[pid, self->fd - 1]; 160 161 /* save details */ 162 @Avg[self->host] = avg((timestamp - this->start)/1000000); 163 @Max[self->host] = max((timestamp - this->start)/1000000); 164 @Num[self->host] = count(); 165 166 /* clear vars */ 167 start[pid, self->fd - 1] = 0; 168 host[pid, self->fd - 1] = 0; 169 self->host = 0; 170 self->fd = 0; 171 } 172 173 /* 174 * Output report 175 */ 176 dtrace:::END 177 { 178 printf("%-32s %11s\n", "HOST", "NUM"); 179 printa("%-32s %@11d\n", @Num); 180 181 printf("\n%-32s %11s\n", "HOST", "AVGTIME(ms)"); 182 printa("%-32s %@11d\n", @Avg); 183 184 printf("\n%-32s %11s\n", "HOST", "MAXTIME(ms)"); 185 printa("%-32s %@11d\n", @Max); 186 } 187
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