Resolving problems when you use IMS nodes
Advice for dealing with common problems that can arise when you develop message flows that contain IMS nodes.
Before you begin
- Read about IMS in IBM Information Management System (IMS).
- Ensure that you have set up the IBM® Integration Bus runtime environment correctly, as described in Preparing the environment for IMS nodes.
About this task
How can I tell if my integration node is connected to IMS Connect?
Procedure
- Scenario: You need to check if your integration node is connected to IMS Connect.
- Explanation: You can use SDSF on z/OS to issue a command to see which ports have clients connected to them.
- Solution: Using SDSF, enter the following QUERY
MEMBER command, where IM0ACONN is the
name of your IMS Connect job:
/F IM0ACONN,QRY MEMBER TYPE(IMSCON)The output is in the following format:
This example shows that one client is connected on TCP port 1109, and that the client is connecting from the IP address 9.17.137.11./F IM0ACONN,QRY MEMBER TYPE(IMSCON) HWSC0001I HWS ID=IM0ACONN RACF=Y PSWDMC=N HWSC0001I MAXSOC=50 TIMEOUT=0 HWSC0001I RRS=N STATUS=REGISTERED HWSC0001I VERSION=V10 IP-ADDRESS=009.017.252.024 HWSC0001I SUPER MEMBER NAME= HWSC0001I ADAPTER=N HWSC0001I DATASTORE=IM0A STATUS=ACTIVE HWSC0001I GROUP=IM0AGRNM MEMBER=IM0ACONN HWSC0001I TARGET MEMBER=IM0A HWSC0001I DEFAULT REROUTE NAME=HWS£DEF HWSC0001I RACF APPL NAME= HWSC0001I OTMA ACEE AGING VALUE=2147483647 HWSC0001I OTMA ACK TIMEOUT VALUE=120 HWSC0001I OTMA MAX INPUT MESSAGE=5000 HWSC0001I NO ACTIVE IMSPLEX HWSC0001I PORT=1080 STATUS=ACTIVE HWSC0001I CLIENTID USERID TRANCODE STATUS SECOND CLNTPORT IP-ADDRESS HWSC0001I HWSEHYMO JDOE IVTNO RECV 21 1109 009.017.137.11 HWSC0001I TOTAL CLIENTS=1 RECV=1 CONN=0 XMIT=0 OTHER=0You can run netstat on that system to find out in which process that client is running.
Use the following IMS command to view the TPIPEs that are created for those connections:/DISPLAY TMEMBER IMSConnect_Name TPIPE ALL- For transactions that have a commit mode of 1, the TPIPE name is the port number that is used for that interaction (for example, 1080 in the previous example).
- For transactions that have a commit mode of 0, the TPIPE name is the same as the client ID (for example, HWSEHYMO in the previous example). The client ID is generated automatically in the IMSRequest node.
How can I discover the correct settings for Hostname, Portnumber, and DataStoreName?
Procedure
- Scenario: Your integration node fails to connect to IMS and you want to verify your settings.
- Explanation: You can use SDSF on z/OS to issue a command to see members of the XCF group to which your IMS control region belongs. One of these members should be IMS Connect. You can then run a command against IMS Connect to discover these properties.
- Solution: Use SDSF to enter the following command:
where xx is the reply ID for your IMS control region job./xx/display OTMAFor example, if you see
....... *26 DFS996I *IMS READY* IM0Ain S.log, run the command/26/DISPLAY OTMA.The output from that command shows the name of the IMS Connect that is in the same XCF group as this IMS control region:DFS000I GROUP/MEMBER XCF-STATUS USER-STATUS SECURITY TIBINPT SMEM IM0A DFS000I DRUEXIT T/O IM0A DFS000I IM0AGRNM IM0A DFS000I -IM0A ACTIVE SERVER CHECK IM0A DFS000I -IM0A N/A 0 IM0A DFS000I -IM0ACONN ACTIVE ACCEPT TRAFFIC CHECK 05000 IM0A DFS000I *08350/175112* IM0AUse SDSF to enter the following QUERY MEMBER command, where IM0ACONN is the name of your IMS Connect job that was reported by the previous command:
The output is in the following format:/F IM0ACONN,QRY MEMBER TYPE(IMSCON)/F IM0ACONN,QRY MEMBER TYPE(IMSCON) HWSC0001I HWS ID=IM0ACONN RACF=Y PSWDMC=N HWSC0001I MAXSOC=50 TIMEOUT=0 HWSC0001I RRS=N STATUS=REGISTERED HWSC0001I VERSION=V10 IP-ADDRESS=009.017.252.024 HWSC0001I SUPER MEMBER NAME= HWSC0001I ADAPTER=N HWSC0001I DATASTORE=IM0A STATUS=ACTIVE HWSC0001I GROUP=IM0AGRNM MEMBER=IM0ACONN HWSC0001I TARGET MEMBER=IM0A HWSC0001I DEFAULT REROUTE NAME=HWS£DEF HWSC0001I RACF APPL NAME= HWSC0001I OTMA ACEE AGING VALUE=2147483647 HWSC0001I OTMA ACK TIMEOUT VALUE=120 HWSC0001I OTMA MAX INPUT MESSAGE=5000 HWSC0001I NO ACTIVE IMSPLEX HWSC0001I PORT=1080 STATUS=ACTIVE HWSC0001I CLIENTID USERID TRANCODE STATUS SECOND CLNTPORT IP-ADDRESS HWSC0001I HWSEHYMO JDOE IVTNO RECV 21 1109 009.017.137.11 HWSC0001I TOTAL CLIENTS=1 RECV=1 CONN=0 XMIT=0 OTHER=0
What should I do when my transaction times out?
Procedure
- Scenario: The transaction times out and the message is sent to the Timeout terminal, or an exception is issued.
- Explanation: Your transaction is taking longer than
the values that are set for the execution or socket timeouts, therefore
the node stops waiting for a response, and issues an exception or
sends the message to the Timeout terminal. If the transaction subsequently completes successfully, the result depends on the commit mode that is set on the IMSRequest node:
- If the Commit mode property is set to 0: COMMIT_THEN_SEND, the unit of work is committed and the response is discarded.
- If the Commit mode property is set to 1: SEND_THEN_COMMIT, the response is not sent and the unit of work is rolled back.
- Solution: Increase the execution or socket timeout
values to give enough time for the transaction to complete.
- Configure the execution timeout by using the Timeout waiting for a transaction to be executed property on the IMSRequest node.
- Configure the socket timeout on the configurable service.
How many physical connections should I expect in IMS Connect?
Procedure
- Scenario: You need to set the values for the number of connections that are required by clients that are connecting to IMS Connect.
- Explanation: The number of physical connections
that can be opened in IMS Connect
is limited. The limit depends on the MAXSOC and MAXFEILEPROC settings.
- The MAXSOC setting in IMS Connect determines the number of sockets that can be opened in IMS, which is the number of ports on which IMS listens for connections, plus the number of physical connections.
- MAXFILEPROC is a UNIX System Services (USS) setting, which must be greater than or equal to MAXSOC, otherwise IMS reaches this limit before it reaches its own MAXSOC limit.
If the MAXSOC value is reached, IMS Connect issues warning message HWSS0771W, and refuses new requests for connections from clients. This behavior continues until the number of open sockets is below the limit (for example, after some clients have disconnected).
If the MAXFILEPROC value is reached, USS issues information message BPXI040I.
- Solution: When you set values for MAXSOC and MAXFILEPROC,
consider how many clients are likely to connect concurrently to IMS Connect, and how many connections
those clients will require. IBM Integration Bus acts as a client to IMS Connect, and opens connections to IMS Connect. Therefore, find out how many connections are required by IBM Integration Bus by gathering the following information:
- The number of message flows with IMS nodes that are deployed
- For those message flows, the values of the Additional instances property
The maximum number of connections required for each integration node is determined by the number of threads that can be running concurrently in the IMS nodes. In the following example, three message flows with IMS nodes exist:- Message flow A has 0 additional instances, therefore one thread is running.
- Message flow B has 3 additional instances, therefore four threads can be running concurrently.
- Message flow C has 4 additional instances, therefore five threads can be running concurrently.