From: Aaron Schulz <aschulz@wikimedia.org>
Date: Tue, 12 Nov 2013 17:39:47 +0000 (-0800)
Subject: Expanded use of reauthenticateConnection() beyond just Lua calls
X-Git-Tag: 1.31.0-rc.0~18131
X-Git-Url: https://git.cyclocoop.org/%7B%24www_url%7Dadmin/compta/exercices/bilan.php?a=commitdiff_plain;h=146ea32031dba266831d0f7820f2bc8214f34a58;p=lhc%2Fweb%2Fwiklou.git

Expanded use of reauthenticateConnection() beyond just Lua calls

* Also made it so luaEval() does not clear any previous errors to callers.
  None of the native methods have that behavoir, so this is more consistent.

Bug: 56886
Change-Id: I47d0f52e72b35ec5cb7b92b9cc3488f145b2d7a2
---

diff --git a/includes/clientpool/RedisConnectionPool.php b/includes/clientpool/RedisConnectionPool.php
index c8e98a7d52..6cf7376e09 100644
--- a/includes/clientpool/RedisConnectionPool.php
+++ b/includes/clientpool/RedisConnectionPool.php
@@ -285,9 +285,16 @@ class RedisConnectionPool {
 	}
 
 	/**
-	 * Resend an AUTH request to the redis server (useful after disconnects)
+	 * Re-send an AUTH request to the redis server (useful after disconnects).
 	 *
-	 * This method is for internal use only
+	 * This works around an upstream bug in phpredis. phpredis hides disconnects by transparently
+	 * reconnecting, but it neglects to re-authenticate the new connection. To the user of the
+	 * phpredis client API this manifests as a seemingly random tendency of connections to lose
+	 * their authentication status.
+	 *
+	 * This method is for internal use only.
+	 *
+	 * @see https://github.com/nicolasff/phpredis/issues/403
 	 *
 	 * @param string $server
 	 * @param Redis $conn
@@ -317,6 +324,7 @@ class RedisConnRef {
 	protected $conn;
 
 	protected $server; // string
+	protected $lastError; // string
 
 	/**
 	 * @param $pool RedisConnectionPool
@@ -329,8 +337,29 @@ class RedisConnRef {
 		$this->conn = $conn;
 	}
 
+	public function getLastError() {
+		return $this->lastError;
+	}
+
+	public function clearLastError() {
+		$this->lastError = null;
+	}
+
 	public function __call( $name, $arguments ) {
-		return call_user_func_array( array( $this->conn, $name ), $arguments );
+		$conn = $this->conn; // convenience
+
+		$conn->clearLastError();
+		$res = call_user_func_array( array( $conn, $name ), $arguments );
+		if ( preg_match( '/^ERR operation not permitted\b/', $conn->getLastError() ) ) {
+			$this->pool->reauthenticateConnection( $this->server, $conn );
+			$conn->clearLastError();
+			$res = call_user_func_array( array( $conn, $name ), $arguments );
+			wfDebugLog( 'redis', "Used automatic re-authentication for method '$name'." );
+		}
+
+		$this->lastError = $conn->getLastError() ?: $this->lastError;
+
+		return $res;
 	}
 
 	/**
@@ -369,6 +398,8 @@ class RedisConnRef {
 			wfDebugLog( 'redis', "Lua script error on server $server: " . $conn->getLastError() );
 		}
 
+		$this->lastError = $conn->getLastError() ?: $this->lastError;
+
 		return $res;
 	}