find apache slow query

if you have troubles with apache web server  you can try to find slow http-query. it can  be done using apace logs.
first, you must create specail log format (we  name it 'debug')


in you config file add such line (in debian /etc/apache2/httpd.conf):

LogFormat "%h %D %T %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" debug

where,

Format String	Description
%T	The time taken to serve the request, in seconds.
%D	The time taken to serve the request, in microseconds.

then you can use it format in your www.site config file , for example:

CustomLog /var/log/apache2/www.site-access.log debug

and now apache will write to log file the time taken to serve the request, in microseconds. So you can using cat, awk, tail and other shell command find "slow" query...

for example, find query than take more than 2 second:

# cat /var/log/apache2/www.site-access.log  | awk ' { if($3 > 2)  print $_ }'

Also useful:

The characteristics of the request itself are logged by placing "%" directives in the format string, which are replaced in the log file by the values as follows:

Format String	Description
%%	The percent sign
%a	Remote IP-address
%A	Local IP-address
%B	Size of response in bytes, excluding HTTP headers.
%b	Size of response in bytes, excluding HTTP headers. In CLF format, i.e. a '-' rather than a 0 when no bytes are sent.
%{Foobar}C	The contents of cookie Foobar in the request sent to the server. Only version 0 cookies are fully supported.
%D	The time taken to serve the request, in microseconds.
%{FOOBAR}e	The contents of the environment variable FOOBAR
%f	Filename
%h	Remote host
%H	The request protocol
%{Foobar}i	The contents of Foobar: header line(s) in the request sent to the server. Changes made by other modules (e.g. mod_headers) affect this.
%k	Number of keepalive requests handled on this connection. Interesting if KeepAlive is being used, so that, for example, a '1' means the first keepalive request after the initial one, '2' the second, etc...; otherwise this is always 0 (indicating the initial request). Available in versions 2.2.11 and later.
%l	Remote logname (from identd, if supplied). This will return a dash unless mod_ident is present and IdentityCheck is set On.
%m	The request method
%{Foobar}n	The contents of note Foobar from another module.
%{Foobar}o	The contents of Foobar: header line(s) in the reply.
%p	The canonical port of the server serving the request
%{format}p	The canonical port of the server serving the request or the server's actual port or the client's actual port. Valid formats are canonical, local, or remote.
%P	The process ID of the child that serviced the request.
%{format}P	The process ID or thread id of the child that serviced the request. Valid formats are pid, tid, and hextid. hextid requires APR 1.2.0 or higher.
%q	The query string (prepended with a ? if a query string exists, otherwise an empty string)
%r	First line of request
%R	The handler generating the response (if any).
%s	Status. For requests that got internally redirected, this is the status of the *original* request --- %>s for the last.
%t	Time the request was received (standard english format)
%{format}t	The time, in the form given by format, which should be in strftime(3) format. (potentially localized)
%T	The time taken to serve the request, in seconds.
%u	Remote user (from auth; may be bogus if return status (%s) is 401)
%U	The URL path requested, not including any query string.
%v	The canonical ServerName of the server serving the request.
%V	The server name according to the UseCanonicalName setting.
%X	Connection status when response is completed: X = connection aborted before the response completed. + = connection may be kept alive after the response is sent. - = connection will be closed after the response is sent. (This directive was %c in late versions of Apache 1.3, but this conflicted with the historical ssl %{var}c syntax.)
%I	Bytes received, including request and headers, cannot be zero. You need to enable mod_logio to use this.
%O	Bytes sent, including headers, cannot be zero. You need to enable mod_logio to use this.