The purpose of this wiki is to provide troubleshooting tips if the Outbound Scheduler (SMQS) is in satus WAITING.
This wiki provides notes that may resolve the issue. It will also look at DB statistics and resource problems that may cause the scheduler to WAIT.
Checking the issue:
SMQS will show the following:
A. Other than the notes mentioned below the issue may be caused because of a performance issue reading the RFC tables. This happens only using Oracle databases.
In this case you would see problems doing a Sequential read in SM50 on RFC tables such as TRFCQOUT, ARFCSSTATE or ARFCSSDATA, this can beseen in SM50 or SM66.
If so, note 742950 needs to be applied: Performance affected on Oracle DB with Supplement 11
o You are using an Oracle database Version 9l or higher.
Proceed as described in Note 932975
o You are using an Oracle database that is lower than 9l.
After you import Supplement 11, you must run the RSTRFCCS report.
Change the default settings to 5000 LUWs (NLUW), so that the
program creates different STATUS values in TRFCQOUT and TRFCQIN.
Only with these settings, the INDEX on the STATUS field of the
TRFCQIN and TRFCQOUT tables is correctly used. These entries are
deleted again after the statistics are generated.
The problem can also be caused if there ar not enough resources available.
In this case check trnx SMQS, choose "goto" in the menu and then choose "QRFC Resources". Resources should be available for tRFC and qRFC processing:
If NO resources are available for tRFC and qRFC processing you will see something like:
If this is the case, dialogs will need to be assigned to the Application Server group mentioned in SMQS.
The settings can be changed in RZ12.
However, if dialogs have already been assigned in RZ12 but are not visible in SMQS "Goto" "Resources" then the problem may be that the communication table for the particular server is full.
If so, see note 1180734 Overflow of communication table
The Scheduler may remain in status WAIT if the system cannot cope with the load. To check this, goto transaction SM51, choose "goto", "Server Information" and "Queue Information":
This will then show a screen similar to the following:
If the "requests waiting" value is close to the "Max Req waiting value" this shows a resource issue as the system cannot cope with the load. In this case, you will need to add extra dialog work processes or balance the load over more application servers.
Related SAP Notes/KBA's
977283 Outbound scheduler remains in WAITING status for a long time
1051445 qRFC scheduler does not use all available resourcen
1485789 QRFC: Long running processes in SM50
1484197 ARFCSDATA for one LUW was read by 100 DIA processes
1528988 Wrong Index in Queue Scheduler when accessing TRFCQOUT
1483757 Slow processing tRFC, qRFC in a high load environment