? .DS_Store
? Drupal7.kpf
? ignore_slave.patch
? ignore_slave_3.patch
? ignore_slave_4.patch
? sites/.DS_Store
? sites/default/files
? sites/default/settings.php
Index: includes/database/database.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/database/database.inc,v
retrieving revision 1.55
diff -u -p -r1.55 database.inc
--- includes/database/database.inc	17 Jun 2009 13:40:26 -0000	1.55
+++ includes/database/database.inc	20 Jun 2009 06:01:23 -0000
@@ -2687,6 +2687,22 @@ function db_rewrite_sql($query, $primary
   return $query;
 }
 
+/**
+ * Helper function to get duration lag from variable
+ * if one isn't passed, and then set the session variable
+ * that contains the lag.
+ *
+ * @param $duration
+ *   The amount of time to ignore the slave to give it
+ *   time to refresh after an insert or update.
+ */
+function db_set_ignore_slave($duration = NULL) {
+  if (!$duration) {
+    $duration = variable_get('maximum_replication_lag', 10);
+  }
+  drupal_set_session('ignore_slave_server', REQUEST_TIME + $duration);
+}
+
 
 /**
  * @} End of "ingroup database-legacy".
Index: modules/comment/comment.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/comment/comment.module,v
retrieving revision 1.723
diff -u -p -r1.723 comment.module
--- modules/comment/comment.module	15 Jun 2009 19:28:55 -0000	1.723
+++ modules/comment/comment.module	20 Jun 2009 06:01:23 -0000
@@ -930,6 +930,9 @@ function comment_save($edit) {
             'homepage' => $edit['homepage'],
           ))
           ->execute();
+        // Ignore slave server temporarily to give time for the
+        // saved node to be propagated to the slave
+        db_set_ignore_slave();
         // Tell the other modules a new comment has been submitted.
         comment_invoke_comment($edit, 'insert');
         // Add an entry to the watchdog log.
Index: modules/node/node.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/node/node.module,v
retrieving revision 1.1070
diff -u -p -r1.1070 node.module
--- modules/node/node.module	12 Jun 2009 08:39:38 -0000	1.1070
+++ modules/node/node.module	20 Jun 2009 06:01:23 -0000
@@ -1034,6 +1034,10 @@ function node_save($node) {
 
   // Clear the page and block caches.
   cache_clear_all();
+  
+  // Ignore slave server temporarily to give time for the
+  // saved node to be propagated to the slave
+  db_set_ignore_slave();
 }
 
 /**
Index: modules/system/system.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.module,v
retrieving revision 1.712
diff -u -p -r1.712 system.module
--- modules/system/system.module	16 Jun 2009 08:41:35 -0000	1.712
+++ modules/system/system.module	20 Jun 2009 06:01:23 -0000
@@ -842,6 +842,28 @@ function system_init() {
   drupal_add_css(drupal_get_path('module', 'system') . '/defaults.css');
   drupal_add_css(drupal_get_path('module', 'system') . '/system.css');
   drupal_add_css(drupal_get_path('module', 'system') . '/system-menus.css');
+
+  // Ignore slave database servers for this request.
+  //
+  // In Drupal's distributed database structure, new data is written to the master
+  // and then propagated to the slave servers.  This means there is a lag
+  // between when data is written to the master and when it is available on the slave.
+  // At these times, we will want to avoid using a slave server temporarily.
+  // For example, if a user posts a new node then we want to disable the slave
+  // server for that user temporarily to allow the slave server to catch up.
+  // That way, that user will see their changes immediately while for other
+  // users we still get the benefits of having a slave server, just with slightly
+  // stale data.  Code that wants to disable the slave server should use the 
+  // db_set_ignore_slave() function to set $_SESSION['ignore_slave_server'] to 
+  // the timestamp after which the slave can be re-enabled.
+  if (isset($_SESSION['ignore_slave_server'])) {
+    if ($_SESSION['ignore_slave_server'] >= REQUEST_TIME) {
+      Database::ignoreTarget('default', 'slave');
+    }
+    else {
+      unset($_SESSION['ignore_slave_server']);
+    }
+  }
 }
 
 /**