Marcel Meulemans created DISPATCH-1019:
------------------------------------------
Summary: Messaging instability in networks with many clients /
addresses.
Key: DISPATCH-1019
URL: https://issues.apache.org/jira/browse/DISPATCH-1019
Project: Qpid Dispatch
Issue Type: Bug
Components: Routing Engine
Affects Versions: 1.1.0
Reporter: Marcel Meulemans
After DISPATCH-966 has been fixed I am still experiencing problems in a network
with many clients / addresses. I am running a three node fully connected mesh
of dispatch routers with 10000 attached clients all with two address messaging
at around 100 msg/sec.
In the logs I am seeing the following errors:
{{2018-05-29 14:31:05.145732 +0000 ERROR (error) Invalid message: Insufficient
Data to Determine Tag}}
{{2018-05-29 14:31:05.145748 +0000 ERROR (error) Invalid message: Can't convert
message field body}}
Which, in turn, lead to python errors like:
{{2018-05-29 14:31:05.145971 +0000 ROUTER_MA (trace) RCVD: MAU(id=None pv=1
area=0 mobile_seq=0)}}
{{2018-05-29 14:31:05.146130 +0000 ROUTER (error) Exception in control message
processing}}
{{Traceback (most recent call last):}}
{{ File "/usr/lib/python2.7/qpid_dispatch_internal/router/engine.py", line 157,
in handleControlMessage}}
{{ self.mobile_address_engine.handle_mau(msg, now)}}
{{ File "/usr/lib/python2.7/qpid_dispatch_internal/router/mobile.py", line 97,
in handle_mau}}
{{ node = self.node_tracker.router_node(msg.id)}}
{{ File "/usr/lib/python2.7/qpid_dispatch_internal/router/node.py", line 363,
in router_node}}
{{ return self.nodes[node_id]}}
{{KeyError: None}}
{{2018-05-29 14:31:05.146175 +0000 ROUTER (error) Control message error:
opcode=MAU body=None}}
I have tracked down the cause of the "Insufficient Data to Determine Tag"
message to the following: During the call to {{qd_parse}} of the {{MAU}}
message the {{qd_iterator_t}} reaches the end of the buffer list before it
should. Specifically the call to {{qd_iterator_advance}} here
[https://github.com/apache/qpid-dispatch/blob/master/src/parse.c#L151,] "fails";
to move forward a certain number of bytes (e.g. 31) even though the
{{iterator->view_pointer->remaining}} value has plenty of bytes left (e.g.
84802). The "fail" is because we reach the end of the buffer list before we
should (here
[https://github.com/apache/qpid-dispatch/blob/master/src/iterator.c#L323|https://github.com/apache/qpid-dispatch/blob/master/src/iterator.c#L323).]).
What I have not been able to figure out yet is why this happens because it is
not consistent. Many large MAU message are parsed correctly only sometimes not.
I am able to reproduce these errors every time I run my tests. There may be a
time component involved because the more logging I to the router code, the less
often the errors seem to occur.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
