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Hi Christophe,
AFAIK, the timestamp of the request is the timestamp when
the first request line
(i.e. GET /index.html HTTP/1.1) is being read by the
server.
The duration is calculated as a delta to this
base.
Regs,
Christian
P.S. In case the timestamp is not enough exact, then try
out modsecurity,
which brings a microtimestamp.
--
Christian Folini, IT 222 Webserver Security Engineer Von: Furmaniak Christophe [mailto:Christophe.Furmaniak@xxxxxxxxxxxxxx] Gesendet: Mittwoch, 29. Oktober 2008 10:44 An: users@xxxxxxxxxxxxxxxx Betreff: Does the "time taken to serve the request (%D)" include the time taken to read the request? Hi, We use a java lib (HttpClient) to measure a web page response
time, the page is served by httpd. We trace the time taken to serve the request using a %D in
the LogFormat directive, but sometimes the duration logged in the access file
does not match the duration measured using HttpClient (less than a 1ms against 3
seconds) We've found that the "missing" time is consumed during the
sending of the request on the HttpClient side (i.e., NOT during the response
reading). My question is: "does the time taken to server the request
include the time taken to read the request from the client"? I had a quick look at modules/loggers/mod_log_config.c and
server/protocol.c. in the mod_log_config.c, I've found: =================================== static const char *log_request_duration(request_rec *r, char
*a) { apr_time_t duration = apr_time_now() -
r->request_time; return apr_psprintf(r->pool, "%"
APR_TIME_T_FMT, apr_time_sec(duration)); } static const char
*log_request_duration_microseconds(request_rec *r, char *a) { return apr_psprintf(r->pool, "%"
APR_TIME_T_FMT,
(apr_time_now() - r->request_time)); } =================================== in the server/protocol.c, ========================= static int read_request_line(request_rec *r,
apr_bucket_brigade *bb){ ?. do
{ apr_status_t rv; /* insure
ap_rgetline allocates memory each time thru the
loop * if there are empty
lines
*/ r->the_request =
NULL; rv =
ap_rgetline(&(r->the_request),
(apr_size_t)(r->server->limit_req_line +
2),
&len, r, 0, bb); if (rv !=
APR_SUCCESS) {
r->request_time = apr_time_now();
/* ap_rgetline returns APR_ENOSPC if it fills up
the *
buffer before finding the end-of-line. This is only going
to *
happen if it exceeds the configured limit for a
request-line.
*/
if (rv == APR_ENOSPC) {
r->status = HTTP_REQUEST_URI_TOO_LARGE;
r->proto_num = HTTP_VERSION(1,0);
r->protocol = apr_pstrdup(r->pool, "HTTP/1.0");
}
return 0; } } while ((len <= 0) &&
(++num_blank_lines < max_blank_lines)); /* we've probably got something to do,
ignore graceful restart requests */ r->request_time =
apr_time_now(); ll = r->the_request; r->method =
ap_getword_white(r->pool, &ll); ?. ========================= I'm neither an httpd expert, nor a C expert, but what I
understand is that the r->request_time "top" is taken when
the request is being read, that's why we cannot see in the access log the time
taken for the request to be sent from the client to the server. Am I wrong? Thanks. -- Christophe Furmaniak Ce message et les pièces jointes sont confidentiels et réservés à l'usage exclusif de ses destinataires. Il peut également être protégé par le secret professionnel. Si vous recevez ce message par erreur, merci d'en avertir immédiatement l'expéditeur et de le détruire. L'intégrité du message ne pouvant être assurée sur Internet, la responsabilité du groupe Atos Origin ne pourra être recherchée quant au contenu de ce message. Bien que les meilleurs efforts soient faits pour maintenir cette transmission exempte de tout virus, l'expéditeur ne donne aucune garantie à cet égard et sa responsabilité ne saurait être recherchée pour tout dommage résultant d'un virus transmis. This e-mail and the documents attached are confidential and intended solely for the addressee; it may also be privileged. If you receive this e-mail in error, please notify the sender immediately and destroy it. As its integrity cannot be secured on the Internet, the Atos Origin group liability cannot be triggered for the message content. Although the sender endeavours to maintain a computer virus-free network, the sender does not warrant that this transmission is virus-free and will not be liable for any damages resulting from any virus transmitted. |
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