Make WANObjectCache sets account for slave lag

[lhc/web/wiklou.git] / includes / MediaWiki.php

diff --git a/includes/MediaWiki.php b/includes/MediaWiki.php
index fbacb25..e29319b 100644 (file)
--- a/includes/MediaWiki.php
+++ b/includes/MediaWiki.php
@@ -471,7 +471,6 @@ class MediaWiki {
         */
        public function run() {
                try {
-                       $this->checkMaxLag();
                        try {
                                $this->main();
                        } catch ( ErrorPageError $e ) {
@@ -504,6 +503,14 @@ class MediaWiki {
                $factory->shutdown();
 
                wfDebug( __METHOD__ . ' completed; all transactions committed' );
+
+               // Set a cookie to tell all CDN edge nodes to "stick" the user to the
+               // DC that handles this POST request (e.g. the "master" data center)
+               $request = $this->context->getRequest();
+               if ( $request->wasPosted() && $factory->hasOrMadeRecentMasterChanges() ) {
+                       $expires = time() + $this->config->get( 'DataCenterUpdateStickTTL' );
+                       $request->response()->setCookie( 'UseDC', 'master', $expires );
+               }
        }
 
        /**
@@ -546,33 +553,6 @@ class MediaWiki {
                }
        }
 
-       /**
-        * Checks if the request should abort due to a lagged server,
-        * for given maxlag parameter.
-        * @return bool
-        */
-       private function checkMaxLag() {
-               $maxLag = $this->context->getRequest()->getVal( 'maxlag' );
-               if ( !is_null( $maxLag ) ) {
-                       list( $host, $lag ) = wfGetLB()->getMaxLag();
-                       if ( $lag > $maxLag ) {
-                               $resp = $this->context->getRequest()->response();
-                               $resp->statusHeader( 503 );
-                               $resp->header( 'Retry-After: ' . max( intval( $maxLag ), 5 ) );
-                               $resp->header( 'X-Database-Lag: ' . intval( $lag ) );
-                               $resp->header( 'Content-Type: text/plain' );
-                               if ( $this->config->get( 'ShowHostnames' ) ) {
-                                       echo "Waiting for $host: $lag seconds lagged\n";
-                               } else {
-                                       echo "Waiting for a database server: $lag seconds lagged\n";
-                               }
-
-                               exit;
-                       }
-               }
-               return true;
-       }
-
        private function main() {
                global $wgTitle, $wgTrxProfilerLimits;