FINAL suepr merge step : added all modules to this super repos

sites/all/modules/contrib/dev/performance/README.txt

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+By Khalid Baheyeldin
+
+Copyright 2008 http://2bits.com
+
+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 any cache for which a Drupal caching module is
+  available that transparently integrates with the drupal cache layer. Some
+  examples:
+    http://drupal.org/project/apc
+    http://drupal.org/project/memcache
+    http://drupal.org/project/filecache
+
+* A settings option is available when using summary mode, 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
+memory_get_peak_usage() function, available only in PHP 5.2.x or later.
+
+Only summary logging with Memcache, APC or similar mechanisms are the
+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 per-URL 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:
+--------------
+To configure the Performance Logging and Monitoring module, navigate to
+/admin/config/development/performance-logging. By default, this module creates a
+key for each entry based off of the hostname of the site being accessed. If you
+have a site with multiple domains, it is recommended to specify a shared key
+between all sites in your settings.php file:
+
+  $conf['performance_key'] = 'example_key';
+
+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 settings.php looks like this:
+
+  $conf['cache_backends'][] = './sites/all/modules/memcache/memcache.inc';
+  $conf['cache_default_class'] = 'MemCacheDrupal';
+  // Prevent special cache_form bin from being assigned to a volatile cache
+  // storage implementation
+  $conf['cache_class_cache_form'] = 'DrupalDatabaseCache';
+
+  $conf['memcache_servers'] = array(
+    '127.0.0.1:11211' => 'default',
+    // More bins here ....
+    '127.0.0.1:11311' => 'performance',
+  );
+  $conf['memcache_bins'] = array(
+    'cache_performance' => 'performance',
+  );
+
+Note that since version 2.x, you can use any Drupal caching module available
+that transparently integrates with the drupal cache layer (like the apc or
+filecache modules).
+
+Statistics:
+-----------
+You can view the recorded performance statistics (summary and details) at
+/admin/reports/performance-logging
+
+Drush support
+-------------
+Drush support has been integrated as well. You can check the summary and detail
+logs using the performance-summary (aliased as perf-sm) and performance-detail
+(aliased as perf-dt) commands. Some examples:
+
+  Retrieve last 15 entries from the detail log:
+    drush performance-detail 15
+
+  Retrieve last 20 summary log entries sorted by the number of queries,
+  descending:
+    drush performance-summary 20 query_count
+
+  Retrieve last 35 entries from the detail log sorted by size, ascending:
+    drush performance-detail 35 bytes asc
+
+Use drush perf-sm --help or drush perf-dt --help to see a full explanation.
+
+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://drupal.org/project/performance
+
+Author
+------
+Khalid Baheyeldin (http://baheyeldin.com/khalid and http://2bits.com)
+
+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.