[Checkins] SVN: Sandbox/J1m/resumelb/src/zc/resumelb/lb. Handle case of worker disconnection after calling start_response.

Mon Mar 5 16:28:47 UTC 2012

Log message for revision 124518:
  Handle case of worker disconnection after calling start_response.
  

Changed:
  U   Sandbox/J1m/resumelb/src/zc/resumelb/lb.py
  U   Sandbox/J1m/resumelb/src/zc/resumelb/lb.test

-=-
Modified: Sandbox/J1m/resumelb/src/zc/resumelb/lb.py
===================================================================

--- Sandbox/J1m/resumelb/src/zc/resumelb/lb.py	2012-03-05 14:05:01 UTC (rev 124517)
+++ Sandbox/J1m/resumelb/src/zc/resumelb/lb.py	2012-03-05 16:28:45 UTC (rev 124518)
@@ -72,8 +72,6 @@
                 self.pool.put(worker)
                 return result
             except zc.resumelb.util.Disconnected:
-                # XXX need to be more careful about whether
-                # start_response was called.
                 if (int(env.get('CONTENT_LENGTH', 0)) == 0 and
                     env.get('REQUEST_METHOD') in retry_methods
                     ):
@@ -315,9 +313,9 @@
                     if data:
                         logger.debug('yield %r', data)
                         yield data
-                    elif data is None:
-                        raise zc.resumelb.util.Disconnected()
                     else:
+                        if data is None:
+                            logger.warning('Disconnected while returning body')
                         break
             finally:
                 self.end(rno)

Modified: Sandbox/J1m/resumelb/src/zc/resumelb/lb.test
===================================================================
--- Sandbox/J1m/resumelb/src/zc/resumelb/lb.test	2012-03-05 14:05:01 UTC (rev 124517)
+++ Sandbox/J1m/resumelb/src/zc/resumelb/lb.test	2012-03-05 16:28:45 UTC (rev 124518)
@@ -239,8 +239,11 @@
 requests are resubmitted to another worker. All other requests
 generate a 500 response.
 
+Also, if a worker has already sent part of the response and
+disconnects, that response is simply truncated.
+
     >>> greenlets = []
-    >>> for method in ('GET', 'HEAD', 'PUT', 'POST', 'DELETE',
+    >>> for method in ('GET', 'GET', 'HEAD', 'PUT', 'POST', 'DELETE',
     ...                'OPTIONS', 'TRACE'):
     ...     app = webtest.TestApp(lb.handle_wsgi)
     ...     greenlets.append(
@@ -258,12 +261,19 @@
     7 <type 'dict'>
     8 <type 'dict'>
     9 <type 'dict'>
+    10 <type 'dict'>
 
+Now, let's send a partial response from the first GET:
+
+    >>> write_message(worker1, 3, ('200 OK', [
+    ...   ('Content-Length', '42'), ('Content-Type', 'text/html')]))
+    >>> gevent.sleep(.01)
+
 Now, we'll disconnect worker1:
 
     >>> worker1.close()
 
-The GET and HEAD request will be send to worker2:
+The second GET and the HEAD request will be send to worker2:
 
     >>> rno1, env1 = read_message(worker2)
     >>> rno, blank = read_message(worker2)
@@ -289,6 +299,7 @@
     >>> for g in greenlets:
     ...    g.join()
     ...    print repr(g.value)
+    <200 OK text/html no body>
     <200 OK text/html body='Hello test\n'>
     <200 OK text/html no body>
     <502 Bad Gateway text/html body='\n<html><...l>\n'/159>
@@ -297,7 +308,7 @@
     <502 Bad Gateway text/html body='\n<html><...l>\n'/159>
     <502 Bad Gateway text/html body='\n<html><...l>\n'/159>
 
-    >>> print greenlets[2].value.body
+    >>> print greenlets[3].value.body
     <BLANKLINE>
     <html><meta http-equiv="refresh" content="1"><body>
     The server was unable to handle your request due to a transient failure.
@@ -401,7 +412,7 @@
     >>> len(lb.pool.workers)
     2
 
-Because the lb didn't reconnect, out's socket is till the one from
+Because the lb didn't reconnect, our's socket is till the one from
 before that we closed:
 
     >>> out.socket is outsocket

