diff --git a/.appveyor.yml b/.appveyor.yml
index 63a9c0ddb73..4e0b54d3269 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -22,21 +22,21 @@ environment:
     driver: sqlsrv
     db_version: sql2008r2sp2
     coverage: yes
-    php: 7.2
+    php: 7.3
   - db: mssql
     driver: sqlsrv
     db_version: sql2012sp1
-    php: 7.2
+    php: 7.3
     coverage: yes
   - db: mssql
     driver: sqlsrv
     db_version: sql2017
     coverage: no
-    php: 7.2
+    php: 7.3
   - db: mssql
     driver: pdo_sqlsrv
     db_version: sql2017
-    php: 7.2
+    php: 7.3
     coverage: yes
 
 init:
@@ -103,7 +103,7 @@ install:
             New-Item -path c:\tools -name ocular -itemtype directory
           }
           if (!(Test-Path c:\tools\ocular\ocular.phar)) {
-            appveyor-retry appveyor DownloadFile https://github.com/scrutinizer-ci/ocular/releases/download/1.5.2/ocular.phar -Filename C:\tools\ocular\ocular.phar
+            appveyor-retry appveyor DownloadFile https://github.com/scrutinizer-ci/ocular/releases/download/1.6.0/ocular.phar -Filename C:\tools\ocular\ocular.phar
             Set-Content -path 'C:\tools\ocular\ocular.bat' -Value ('@php C:\tools\ocular\ocular.phar %*')
           }
 
diff --git a/.travis.yml b/.travis.yml
index e0d87665991..48a718a0329 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -32,7 +32,7 @@ script:
 after_script:
   - |
     if [ "x$COVERAGE" == "xyes" ]; then
-      travis_retry wget https://github.com/scrutinizer-ci/ocular/releases/download/1.5.2/ocular.phar
+      travis_retry wget https://github.com/scrutinizer-ci/ocular/releases/download/1.6.0/ocular.phar
       travis_retry php ocular.phar code-coverage:upload --format=php-clover clover.xml
     fi
 
diff --git a/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php b/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php
index c46ddc63dd7..a98c0de9e54 100644
--- a/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php
+++ b/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php
@@ -90,8 +90,15 @@ public function convertException($message, DriverException $exception)
             case '1429':
             case '2002':
             case '2005':
+            case '2054':
                 return new Exception\ConnectionException($message, $exception);
 
+            case '2006':
+                if ($exception instanceof Driver\Mysqli\MysqliConnectionException || $exception instanceof PDOConnectionException) {
+                    return new Exception\ConnectionException($message, $exception);
+                }
+                break;
+
             case '1048':
             case '1121':
             case '1138':
diff --git a/lib/Doctrine/DBAL/Driver/Mysqli/MysqliConnection.php b/lib/Doctrine/DBAL/Driver/Mysqli/MysqliConnection.php
index 1f1a1d218c3..871755702e6 100644
--- a/lib/Doctrine/DBAL/Driver/Mysqli/MysqliConnection.php
+++ b/lib/Doctrine/DBAL/Driver/Mysqli/MysqliConnection.php
@@ -68,7 +68,7 @@ public function __construct(array $params, $username, $password, array $driverOp
         });
         try {
             if (! $this->conn->real_connect($params['host'], $username, $password, $dbname, $port, $socket, $flags)) {
-                throw new MysqliException($this->conn->connect_error, $this->conn->sqlstate ?? 'HY000', $this->conn->connect_errno);
+                throw new MysqliConnectionException($this->conn->connect_error, $this->conn->sqlstate ?? 'HY000', $this->conn->connect_errno);
             }
         } finally {
             restore_error_handler();
diff --git a/lib/Doctrine/DBAL/Driver/Mysqli/MysqliConnectionException.php b/lib/Doctrine/DBAL/Driver/Mysqli/MysqliConnectionException.php
new file mode 100644
index 00000000000..bd26b739ea3
--- /dev/null
+++ b/lib/Doctrine/DBAL/Driver/Mysqli/MysqliConnectionException.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace Doctrine\DBAL\Driver\Mysqli;
+
+/**
+ * Exception thrown in case the mysqli driver errors while connecting.
+ */
+class MysqliConnectionException extends MysqliException
+{
+}
diff --git a/lib/Doctrine/DBAL/Driver/PDOConnection.php b/lib/Doctrine/DBAL/Driver/PDOConnection.php
index 336542ea50a..d851789f6a8 100644
--- a/lib/Doctrine/DBAL/Driver/PDOConnection.php
+++ b/lib/Doctrine/DBAL/Driver/PDOConnection.php
@@ -28,7 +28,7 @@ public function __construct($dsn, $user = null, $password = null, ?array $option
             $this->setAttribute(PDO::ATTR_STATEMENT_CLASS, [PDOStatement::class, []]);
             $this->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
         } catch (\PDOException $exception) {
-            throw new PDOException($exception);
+            throw new PDOConnectionException($exception);
         }
     }
 
diff --git a/lib/Doctrine/DBAL/Driver/PDOConnectionException.php b/lib/Doctrine/DBAL/Driver/PDOConnectionException.php
new file mode 100644
index 00000000000..61de97d103f
--- /dev/null
+++ b/lib/Doctrine/DBAL/Driver/PDOConnectionException.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace Doctrine\DBAL\Driver;
+
+/**
+ * PDOConnectionException is used to distinguish connection failures from regular PDOExceptions.
+ */
+class PDOConnectionException extends PDOException
+{
+}
diff --git a/tests/continuousphp/bootstrap.php b/tests/continuousphp/bootstrap.php
index 9f6b0971a79..882812d0657 100644
--- a/tests/continuousphp/bootstrap.php
+++ b/tests/continuousphp/bootstrap.php
@@ -23,7 +23,7 @@
     $file = $_SERVER['argv'][$pos + 1];
 
     register_shutdown_function(static function () use ($file) : void {
-        $cmd = 'wget https://github.com/scrutinizer-ci/ocular/releases/download/1.5.2/ocular.phar'
+        $cmd = 'wget https://github.com/scrutinizer-ci/ocular/releases/download/1.6.0/ocular.phar'
             . ' && php ocular.phar code-coverage:upload --format=php-clover ' . escapeshellarg($file);
 
         passthru($cmd);
diff --git a/tests/travis/install-db2-ibm_db2.sh b/tests/travis/install-db2-ibm_db2.sh
index b59bb6396fd..4c8a0cda075 100644
--- a/tests/travis/install-db2-ibm_db2.sh
+++ b/tests/travis/install-db2-ibm_db2.sh
@@ -4,6 +4,9 @@ set -ex
 
 echo "Installing extension"
 (
+    # https://travis-ci.community/t/then-sudo-apt-get-update-failed-public-key-is-not-available-no-pubkey-6b05f25d762e3157-in-ubuntu-xenial/1728/12
+    sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 6B05F25D762E3157
+
     # updating APT packages as per support recommendation
     sudo apt -y -q update
     sudo apt install ksh