We have a 3rd party app running on the I, which communicates with an HTTP instance over loopback 127.0.0.1, port 7688.
We're seeing Error on read socket messages in QYSOPR from the 3rd party app, about 50 per day, no pattern.
The 3rd party app doesn't fail, it resends the transaction.
I setup TRCCNN, which reveals RST is occurring at the time of the read socket errors.
I also noticed an ACK PSH FIN occurring prior to the RST.
How do I determine what is causing the RST occur.
I have the HTTP instance set not to timeout.
KeepAliveTimeout 86400
I found IBM tech doc, which states below.
http://www-01.ibm.com/support/docview.wss?uid=swg21305235
Why does TCPIP reset a connection?
Resolving the problem
Reasons for TCP/IP resets:
* If a connection is un-orderly terminated, such as when a client box is recycled, TCP will reset the connection.
* If an application requests a connect to a port and IP address on which no server is listening, TCP will send a reset.
* If an application closes a socket with data still in the application receive buffer, the connection is reset to allow the remote partner to know that the data was not delivered.
* If data arrives for a connection that has been closed the connection will be reset.
* If an application closes a socket and sets the linger socket option to zero, TCP will reset the connection; as linger 0 instructs TCP not allow the connection to linger waiting for retransmitted packets.
* If an invalid TCP segment arrives for a connection, for example, a bad acknowledge or sequence number can cause a reset.
* When the connect request times out, TCP will stop trying to connect to a particular port and ip address and reset the connection.
* A Firewall can reset connections if the packet does not adhere to the firewall rules and policies. For example a source or destination port or IP address does not match the firewall rule or policy.
* When the retransmit timer expires, TCP will stop trying to retransmit a packet and reset the connection.
* A bad hardware device can cause a TCP reset.
Thank You
_____
Paul Steinmetz
IBM i Systems Administrator
Pencor Services, Inc.
462 Delaware Ave
Palmerton Pa 18071
610-826-9117 work
610-826-9188 fax
610-349-0913 cell
610-377-6012 home
psteinmetz@xxxxxxxxxx<mailto:psteinmetz@xxxxxxxxxx>
http://www.pencor.com/
midrange.com
