 readme  id readmetxt v 1141 20100516 221428 kbahey exp by khalid baheyeldin copyright 2008 http 2bitscom description this module provides performance statistics logging for a site such as page generation times and memory usage for each page load this module is useful for developers and site administrators alike to identify pages that are slow to generate or use excessive memory features include settings to enable detailed logging or summary logging the module defaults to no logging at all detailed logging causes one database row to be written for each page load of the site the data includes page generation time in milliseconds and the number of bytes allocated to php time stamp etc summary logging logs the average and maximum page generation time average and maximum memory usage last access time and number of accesses for each path summary can be logged to memcache if configured so as to not cause extra load on the database this works when apc cannot be used eg certain fastcgi configurations or when you have many web servers on different boxes this mode is recommended for live sites summary can be logged to apc if installed and the apc data cache is shared so as to not cause extra load on the database this mode is recommended for live sites a settings option is available when using summary mode with apc to exclude pages with less than a certain number of accesses useful for large sites support for normal page cache note that detailed logging is only suitable for a site that is in development or testing do not enable detailed logging on a live site the memory measurement feature of this module depends on the memorygetpeakusage function available only in php 52x or later only summary logging with memcache or apc are recommended mode for live sites with a threshold of 2 or more note on completeness please note that when summary logging to apc or memcache the data captured in the summary will not be comprehensive reflecting every single page view for every url the reason for this is that there is no atomic locking when updating the data structures that store perurl statistics in this module this means that the values you get when using these storage caches are only samples and would miss some page views depending on how busy the site is for memcache there is way to implement locking using the mc increment and or mc add as well however there is a risk if these are implemented that there will be less concurrency and we can cause a site to slow down configuration if you are using memcache then you need to configure an extra bin for performance if you have multiple web server boxes then it is best to centralize this bin for all the boxes so you get combined statistics your settingsphp looks like this conf array cacheinc sites all modules memcache memcacheinc memcacheservers array 12700111211 default more bins here 12700111311 performance memcachebins array cacheperformance performance bugs features patches if you want to report bugs feature requests or submit a patch please do so at the project page on the drupal web site at http drupalorg project performance author khalid baheyeldin http baheyeldincom khalid and http 2bitscom if you use this module find it useful and want to send the author a thank you note then use the feedback contact page at the url above the author can also be contacted for paid customizations of this and other modules  