ResLog is a PHP extension to log resource usage of PHP scripts.

The data comes from the getrusage system call (LAMP stack required). Log messages can go to syslog or to a file specified.

It is possible to use separate files for different virtual hosts.

Log messages have the following format (similarly to Apache's access log):

[ http_host SPACE ] remote_addr SPACE "[" request_time "]" SPACE
<"> request_uri <"> SPACE pid SPACE
"-" times SPACE "-" SPACE io SPACE "-" SPACE memory

times : u_elapsed SPACE s_elapsed SPACE t_elapsed 
io : blk_in_count SPACE blk_out_count
memory : mem_peak SPACE mem_peak_real SPACE hardfault

http_host : Name of the host from the SERVER_NAME environment, if reslog.usecanonical is enabled (default). Otherwise the host name in use by the client from the HTTP_HOST environment. This can be useful in case of multiple ServerAlias directives.

remote_addr : IP address of the remote host (from the REMOTE_ADDR environment variable).

request_time : Time of the request.

request_uri : Full URI of this request (from the REQUEST_URI environment variable).

pid : Current process ID.

u_elapsed : CPU time (in microseconds), this thread spend in user mode.

s_elapsed : CPU time (in microseconds), this thread spend in system mode.

t_elapsed : Elapsed time (microseconds) from starting the script to finishing. This is not indicative of the current script's performance as other threads will have an impact on this amount.

blk_in_count : Number of block input operations (reads).

blk_out_count : Number of block output operations (writes).

mem_peak : Peak memory usage. The value reported by memory_get_peak_usage(false).

mem_peak_real : Real peak memory usage. The value reported by memory_get_peak_usage(true).

hardfault : "Hard" page faults (where I/O operations were needed).

Get the binary with the following commands:

phpize
./configure
make

Install it (requires root privileges):

sudo make install

Activate the extension by adding the follwing to your php.ini:

extension=reslog.so

You will have to restart Apache for the changes to take effect.

The extension has the following parameters (also settable in .htaccess but not with ini_set).

Note: It is strongly recommended to use php_admin_flag for all the settings if you are operating a shared hosting environment.

reslog.file : String, name of the file to use for log messages. (File operations will be done with the same privileges with which the script is executed).

reslog.hideuri : Request URI will be replaced by "/".

reslog.showhost : Boolean, determines whether to prefix log lines with the server's name.

reslog.syslog : Boolean, if enabled all logging will be done through the syslog facility. (Ignoring reslog.file setting).

reslog.usecanonical : Boolean, if enabled (default) the server's name will be read from SERVER_NAME, otherwise HTTP_HOST will be used. (Last one is relevant for virtual hosts with aliases. Please consult Apache's manual for the difference).

ResLog should show up in the output of phpinfo displaying configuration parameters.