diff --git a/core/modules/dblog/src/Logger/DbLog.php b/core/modules/dblog/src/Logger/DbLog.php
index a841430..32f84e3 100644
--- a/core/modules/dblog/src/Logger/DbLog.php
+++ b/core/modules/dblog/src/Logger/DbLog.php
@@ -9,7 +9,8 @@
 
 use Drupal\Component\Utility\Unicode;
 use Drupal\Core\Database\Connection;
-use Drupal\Component\Utility\SafeMarkup;
+use Drupal\Core\Database\Database;
+use Drupal\Core\Database\DatabaseException;
 use Drupal\Core\DependencyInjection\DependencySerializationTrait;
 use Drupal\Core\Logger\LogMessageParserInterface;
 use Drupal\Core\Logger\RfcLoggerTrait;
@@ -23,11 +24,16 @@ class DbLog implements LoggerInterface {
   use DependencySerializationTrait;
 
   /**
+   * The dedicated database connection target to use for log entries.
+   */
+  const DEDICATED_DBLOG_CONNECTION_TARGET = 'dedicated_dblog';
+
+  /**
    * The database connection object.
    *
    * @var \Drupal\Core\Database\Connection
    */
-  protected $database;
+  protected $connection;
 
   /**
    * The message's placeholders parser.
@@ -44,8 +50,8 @@ class DbLog implements LoggerInterface {
    * @param \Drupal\Core\Logger\LogMessageParserInterface $parser
    *   The parser to use when extracting message variables.
    */
-  public function __construct(Connection $database, LogMessageParserInterface $parser) {
-    $this->database = $database;
+  public function __construct(Connection $connection, LogMessageParserInterface $parser) {
+    $this->connection = $connection;
     $this->parser = $parser;
   }
 
@@ -60,21 +66,52 @@ public function log($level, $message, array $context = array()) {
     // translated too in runtime.
     $message_placeholders = $this->parser->parseMessagePlaceholders($message, $context);
 
-    $this->database
-      ->insert('watchdog')
-      ->fields(array(
-        'uid' => $context['uid'],
-        'type' => Unicode::substr($context['channel'], 0, 64),
-        'message' => $message,
-        'variables' => serialize($message_placeholders),
-        'severity' => $level,
-        'link' => $context['link'],
-        'location' => $context['request_uri'],
-        'referer' => $context['referer'],
-        'hostname' => Unicode::substr($context['ip'], 0, 128),
-        'timestamp' => $context['timestamp'],
-      ))
-      ->execute();
+    try {
+      $this->connection
+        ->insert('watchdog')
+        ->fields(array(
+          'uid' => $context['uid'],
+          'type' => Unicode::substr($context['channel'], 0, 64),
+          'message' => $message,
+          'variables' => serialize($message_placeholders),
+          'severity' => $level,
+          'link' => $context['link'],
+          'location' => $context['request_uri'],
+          'referer' => $context['referer'],
+          'hostname' => Unicode::substr($context['ip'], 0, 128),
+          'timestamp' => $context['timestamp'],
+        ))
+        ->execute();
+    }
+    catch (\Exception $e) {
+      // When running Drupal on MySQL or MariaDB you can run into several errors
+      // that corrupt the database connection. Some examples for these kind of
+      // errors on the database layer are "1100 - Table 'xyz' was not locked
+      // with LOCK TABLES" and "1153 - Got a packet bigger than
+      // 'max_allowed_packet' bytes". If such an error happens, the MySQL server
+      // invalidates the connection and answers all further requests in this
+      // connection with "2006 - MySQL server had gone away". In that case the
+      // insert statement above results in a database exception. To ensure that
+      // the causal error is written to the log we try once to open a dedicated
+      // connection and write again.
+      if (
+        // Only handle database related exceptions.
+        ($e instanceof DatabaseException || $e instanceof \PDOException) &&
+        // Avoid an endless loop of re-write attempts.
+        $this->connection->getTarget() != self::DEDICATED_DBLOG_CONNECTION_TARGET
+      ) {
+        // Open a dedicated connection for logging.
+        $key = $this->connection->getKey();
+        $info = Database::getConnectionInfo($key);
+        Database::addConnectionInfo($key, self::DEDICATED_DBLOG_CONNECTION_TARGET, $info['default']);
+        $this->connection = Database::getConnection(self::DEDICATED_DBLOG_CONNECTION_TARGET, $key);
+        // Now try once to log the error again.
+        $this->log($level, $message, $context);
+      }
+      else {
+        throw $e;
+      }
+    }
   }
 
 }
diff --git a/core/modules/dblog/src/Tests/ConnectionFailureTest.php b/core/modules/dblog/src/Tests/ConnectionFailureTest.php
new file mode 100644
index 0000000..345c736
--- /dev/null
+++ b/core/modules/dblog/src/Tests/ConnectionFailureTest.php
@@ -0,0 +1,48 @@
+<?php
+
+/**
+ * @file
+ * Definition of \Drupal\dblog\Tests\ConnectionFailureTest.
+ */
+
+namespace Drupal\dblog\Tests;
+
+use Drupal\Core\Database\Database;
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests logging of connection failures.
+ *
+ * @group dblog
+ */
+class ConnectionFailureTest extends WebTestBase {
+
+  public static $modules = array('dblog');
+
+  /**
+   * Tests logging of connection failures.
+   */
+  function testConnectionFailureLogging() {
+    $logger = \Drupal::service('logger.factory');
+
+    // MySQL errors like "1153 - Got a packet bigger than 'max_allowed_packet'
+    // bytes" or "1100 - Table 'xyz' was not locked with LOCK TABLES" lead to a
+    // database connection unusable for further requests. All further request
+    // will result in an "2006 - MySQL server had gone away" error. As a
+    // consequence it's impossible to use this connection to log the causing
+    // initial error itself. Using Database::closeConnection() we simulate such
+    // a corrupted connection. In this case dblog has to establish a different
+    // connection by itself to be able to write the log entry.
+    Database::closeConnection();
+
+    // Create a log entry.
+    $logger->get('php')->error('testConnectionFailureLogging');
+
+    // Re-establish the default database connection.
+    Database::getConnection();
+
+    $wid = db_query("SELECT MAX(wid) FROM {watchdog} WHERE message = 'testConnectionFailureLogging'")->fetchField();
+    $this->assertTrue($wid, 'Watchdog entry has been stored in database.');
+  }
+
+}