Bugfix #41302 - Add an explicit reconnect for failed Redis connections

src/Illuminate/Redis/Connections/Connection.php

@@ -36,6 +36,13 @@ abstract class Connection
      */
     protected $events;
 
+    /**
+     * Indicates if the connection is invalid and needs to reconnect.
+     *
+     * @var bool
+     */
+    public $shouldReconnect = false;
+
     /**
      * Subscribe to a set of given channels for messages.
      *
@@ -108,12 +115,31 @@ public function psubscribe($channels, Closure $callback)
      * @param  string  $method
      * @param  array  $parameters
      * @return mixed
+     *
+     * @throws \Exception Throws an exception if this connection should not be used
      */
     public function command($method, array $parameters = [])
     {
+        if ($this->shouldReconnect) {
+            // shouldReconnect is checked by RedisManager before returning this connection.
+            // If this exception is triggered, it means some other codepath is using this
+            // which should also be made aware of the public bool shouldReconnect.
+
+            // Basically - if you see this, this is a bug in whatever is NOT using RedisManager
+            // to get Redis objects.
+            throw new \Exception('The Redis connection '.$this->name.' has been marked as failed and needs to be recreated.');
+        }
         $start = microtime(true);
 
-        $result = $this->client->{$method}(...$parameters);
+        try {
+            $result = $this->client->{$method}(...$parameters);
+        } catch (\RedisException $e) {
+            // If there is a RedisException, this connection is no longer usable.
+            // Mark the connection as shouldReconnect, and re-throw the Exception
+            $this->shouldReconnect = true;
+
+            throw $e;
+        }
 
         $time = round((microtime(true) - $start) * 1000, 2);
 

src/Illuminate/Redis/RedisManager.php

@@ -84,11 +84,19 @@ public function connection($name = null)
         $name = $name ?: 'default';
 
         if (isset($this->connections[$name])) {
-            return $this->connections[$name];
+            // If the connection has had a fatal socket error, the \Redis object
+            // in this connection is no longer valid, and needs to be destroyed
+            // and recreated.
+            if (! $this->connections[$name]->shouldReconnect) {
+                return $this->connections[$name];
+            }
+            // Unset and destroy the Connection object to ensure it's cleaned up.
+            unset($this->connections[$name]);
         }
 
         return $this->connections[$name] = $this->configure(
-            $this->resolve($name), $name
+            $this->resolve($name),
+            $name
         );
     }