- added an event for server failover logging

- added support for optional events to plugin system

library/Solarium/Client.php

@@ -457,10 +457,12 @@ class Solarium_Client extends Solarium_Configurable
     protected function _callPlugins($event, $params, $resultOverride = false)
     {
         foreach ($this->_pluginInstances AS $plugin) {
-            $result = call_user_func_array(array($plugin, $event), $params);
+            if (method_exists($plugin, $event)) {
+                $result = call_user_func_array(array($plugin, $event), $params);
 
-            if ($result !== null && $resultOverride) {
-                return $result;
+                if ($result !== null && $resultOverride) {
+                    return $result;
+                }
             }
         }
     }

library/Solarium/Plugin/Loadbalancer.php

@@ -452,20 +452,22 @@ class Solarium_Plugin_Loadbalancer extends Solarium_Plugin_Abstract
      */
     protected function _getLoadbalancedResponse($request) {
 
+        $this->_serverExcludes = array(); // reset for each query
         $adapter = $this->_client->getAdapter();
 
         if ($this->getFailoverEnabled() == true) {
 
             $e = new Solarium_Exception('Maximum number of loadbalancer retries reached');
-            $this->_serverExcludes = array(); // reset
 
             for($i=0; $i<=$this->getFailoverMaxRetries(); $i++) {
                 $options = $this->_getRandomServerOptions();
                 $adapter->setOptions($options);
-                try{
+                try {
                     return $adapter->execute($request);
                 } catch(Solarium_Client_HttpException $e) {
-                    // ignore HTTP errors, try again
+                    // ignore HTTP errors and try again
+                    // but do issue an event for things like logging
+                    $this->_client->triggerEvent('LoadbalancerServerFail', array($options, $e));
                 }
             }