How to troubleshoot long running Transport request:-

I will list the basic steps which you already might know but can be helpful in times of urgency and at times when immediate action is needed:-

To identify the rootcause and solve it accordingly:

1. Go to SE38, execute the report RSTPTEST. It tests the tp status and STMS configuration check.
2. In STMS_IMPORT transaction -> in menu click on Goto -> tp system log .. this will give you if any error is there .
3. Check in SM37 whether RDD* jobs are running or not. If not, schedule them and import of the transport again.
4. Check in SM13 whether update is active or not as sometimes the update gets into error. If it is not active, activate it
5. Check in SM50 if all background workprocesses are in running status and there are zero waiting BGD processes. If so, you will need to wait for the free background workprocess to run RDD* jobs to complete the  import of the transport.
6. Check if any of the filesystems (like sapmnt, oraarch etc) of the Central Instance, Database and  application servers  is 100% full. If so, please add necessary space.

If the above does not helps in solving the issue, try the below things:-

1. Move the files from /usr/sap/trans/tmp to some other FS
2. Delete all ‘in process’ requests from import monitor tab in STMS
3. kill all the work processes from OS level which are running tp
4. make sure that no job is in process named RDDIMPDP
5. Clear entry from TRBAT and TRJOB tables. Also delete any *.LOC file located at /usr/sap/trans/temp location.
6. Reschedule RDDIMPDP Background Job by executing RDDNEWPP report (using SE38) in 000 (under DDIC user) and all the required clients.
7. Try to import the Trans. request(s) again into system using stms_import.
8. The last option would be to restart SAP instance at non-productive time, clear any TRBAT/TRJOB entries, reschedule RDDIMPDP Background Job by executing RDDNEWPP report in 000 (under DDIC user) and all the required clients, and then re-import the Transport Request
9. Also from OS level, one can kill all the TP processes which are in hang state and restart the import process.
   

Hope it helps!!

Best Regards,

Himanshu