From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Mon, 11 Nov 2019 21:17:50 +0000 (-0500)
Subject: Detect PyMySQL connection was killed
X-Git-Tag: rel_1_4_0b1~627^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=31a66b5add39b9193975f9995ce5cd9235179f00;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

Detect PyMySQL connection was killed

Added "Connection was killed" message interpreted from the base
pymysql.Error class in order to detect closed connection, based on reports
that this message is arriving via a pymysql.InternalError() object which
indicates pymysql is not handling it correctly.

Change-Id: If6bbe0eb5993e1996c0c5de752eebaf7446cf93e
References: https://github.com/PyMySQL/PyMySQL/issues/816
Fixes: #4945
---

diff --git a/doc/build/changelog/unreleased_13/4945.rst b/doc/build/changelog/unreleased_13/4945.rst
new file mode 100644
index 0000000000..f94efca20b
--- /dev/null
+++ b/doc/build/changelog/unreleased_13/4945.rst
@@ -0,0 +1,8 @@
+.. change::
+    :tags: bug, mysql
+    :tickets: 4945
+
+    Added "Connection was killed" message interpreted from the base
+    pymysql.Error class in order to detect closed connection, based on reports
+    that this message is arriving via a pymysql.InternalError() object which
+    indicates pymysql is not handling it correctly.
diff --git a/lib/sqlalchemy/dialects/mysql/pymysql.py b/lib/sqlalchemy/dialects/mysql/pymysql.py
index 0b812cbb03..62de1529f2 100644
--- a/lib/sqlalchemy/dialects/mysql/pymysql.py
+++ b/lib/sqlalchemy/dialects/mysql/pymysql.py
@@ -67,7 +67,10 @@ class MySQLDialect_pymysql(MySQLDialect_mysqldb):
         ):
             return True
         elif isinstance(e, self.dbapi.Error):
-            return "Already closed" in str(e)
+            str_e = str(e).lower()
+            return (
+                "already closed" in str_e or "connection was killed" in str_e
+            )
         else:
             return False
 
diff --git a/test/dialect/mysql/test_dialect.py b/test/dialect/mysql/test_dialect.py
index 26c7d38b8c..aac1f64892 100644
--- a/test/dialect/mysql/test_dialect.py
+++ b/test/dialect/mysql/test_dialect.py
@@ -16,6 +16,7 @@ from sqlalchemy.testing import engines
 from sqlalchemy.testing import eq_
 from sqlalchemy.testing import expect_warnings
 from sqlalchemy.testing import fixtures
+from sqlalchemy.testing import mock
 from ...engine import test_execute
 
 
@@ -23,6 +24,33 @@ class DialectTest(fixtures.TestBase):
     __backend__ = True
     __only_on__ = "mysql"
 
+    @testing.combinations(
+        (None, "cONnection was kILLEd", "InternalError", "pymysql", True),
+        (None, "cONnection aLREady closed", "InternalError", "pymysql", True),
+        (None, "something broke", "InternalError", "pymysql", False),
+        (2006, "foo", "OperationalError", "mysqldb", True),
+        (2006, "foo", "OperationalError", "pymysql", True),
+        (2007, "foo", "OperationalError", "mysqldb", False),
+        (2007, "foo", "OperationalError", "pymysql", False),
+    )
+    def test_is_disconnect(
+        self, arg0, message, exc_cls_name, dialect_name, is_disconnect
+    ):
+        class Error(Exception):
+            pass
+
+        dbapi = mock.Mock()
+        dbapi.Error = Error
+        dbapi.ProgrammingError = type("ProgrammingError", (Error,), {})
+        dbapi.OperationalError = type("OperationalError", (Error,), {})
+        dbapi.InterfaceError = type("InterfaceError", (Error,), {})
+        dbapi.InternalError = type("InternalError", (Error,), {})
+
+        dialect = getattr(mysql, dialect_name).dialect(dbapi=dbapi)
+
+        error = getattr(dbapi, exc_cls_name)(arg0, message)
+        eq_(dialect.is_disconnect(error, None, None), is_disconnect)
+
     def test_ssl_arguments_mysqldb(self):
         from sqlalchemy.dialects.mysql import mysqldb