APP04 Recovery (MESSAGING Retransmission Application)

APP04 Purpose:

APP04 processes allow MESSAGING Subscribers to request MESSAGING multicast retransmissions of data they believe they might have missed, on demand. APP04 processes receive MESSAGING Retransmission Requests from MESSAGING Subscribers and send requested data back in return.

Use the following hyperlinks to jump to the desired section of APP04 documentation:

APP04_Recovery_Considerations

APP04_NTM_Control_Commands

APP04_Troubleshooting_Table

APP04_Monitoring_Considerations

APP04 Recovery Considerations:

Stopping/Restart Processes:

- Use NTM Control Utility - Service Control - Process Controller to stop/restart processes.

- Use APP04 nodes only when moving between nodes. There are NAT dependencies on this functionality.

- When stopping/restarting APP04 processes:

1) Notify the MESSAGING Subscribers and work in cooperation with them, as appropriate to situations.

2) Notify Tech Services if moving APP04 processes to alternate nodes and NAT addresses need to change to accommodate move.

3) Stop/Restart the APP04 process.

- APP04 recovery must also be considered if MESSAGING (BFS) Processes are moved between nodes.

See “APP04 (MESSAGING Retransmission) Restart Procedure” in Application Recovery - OMD.docx for more details.

APP04 NTM Control Commands:

There are no APP04 related NTM Control Commands.

APP04 Troubleshooting Table:

APP04 Symptom	Impacts	Response
Node Crashes Evidenced by: - In Solarwinds (and outlook), node and processes will be reported down.	MESSAGING Subscribers will not be able to request MESSAGING Retransmissions. Refer to: Server Recovery - MESSAGING Retransmission.docx Server Specific Recoveries.	1) Refer to: Server Recovery - MESSAGING Retransmission.docx Server Specific Recoveries. 2) Notify Management.

APP04 Monitoring Considerations:

Stats Monitors: BFR Stats	To Start:	Key Indicators to Monitor:	Symptom:	Response:
Processes facilitate MESSAGING Retransmission requests from MESSAGING subscribers utilizing MESSAGING log files. Monitor shows connection status between and MESSAGING Retransmission Subscribers as well as processing statistics.	PROD MENU: Trading Applications Monitoring Menu To Exit: Close Window	- Color of data in columns - Connection Name, - Connection Status, - Retrans Requests, - Retrans Messages Sent, - Connection IP, - Connection Port	Data is RED.	Process is either down or multicast data is not being received by monitor. 1) Check status of process 2) If process is up, call Technical Services.
			Connection status is not LoggedIn.	Subscriber is not logged in and is unable to request or receive MESSAGING retransmissions. 1) Work with firm to reconnect, noting that a stop/restart of the MESSAGING Retrans process on our side will affect every subscriber loggedin at the time - and would not be recommended unless absolutely necessary.
			Retrans Requests Accepted and Sent values are unexpectedly high.	May indicate that there are MESSAGING delivery issues; Especially if seen for several different subscribers. 1) Call Production Support if necessary.