I am using schedulable class which will invoke apex call out. This is the salesforce web service from same org. I am getting the following error:
System.CalloutException: Web service callout failed: WebService returned a SOAP Fault: INVALID_SESSION_ID: Invalid Session ID found in SessionHeader: Illegal Session faultcode=sf:INVALID_SESSION_ID faultactor=
Can any one help me on this? I am using UserInfo.getSessionId() method to get session id.