I use http_post module in frontend. It runs smoothly.
Now I want to trigger http_post module periodically.
I create a background job. But when the job runs, http_post raise exception "communication error".
I don't know what different between frontend and background job. Why I can only run http_post in frontend but fail in background job
What are you using for the RFC_DESTINATION importing parameter of this function module. There are two ways this function can run - from the SAPGui Frontend (RFC Destination SAPHTTP) or from the Application Server (RFC Destination SAPHTTPA). It sounds like this is probably trying to run from the Frontend. I would try forcing to SAPHTTPA and checking in SM59 to make sure this RFC destination is setup correctly. SAPHTTPA should start program saphttp on the application server. It should be a TCP/IP COnnection RFC Type.