Usage of Chunked Streaming Mode Usage in Business Service of OSB 11g and OSB12c

As in the OSB documentation provide by Oracle 

https://docs.oracle.com/cd/E28280_01/dev.1111/e15866/transports.htm#OSBDV288



Chunked Streaming Mode property should be selected if you want to use HTTP chunked transfer encoding to send messages.

Chunked transfer encoding is an HTTP 1.1 specification, and allows clients to parse dynamic data immediately after the first chunk is read. 

Use Checked Streaming Mode  to use HTTP chunked transfer encoding to send messages under HTTP transport configurations for a business service.  Do not use  this option if you have http redirects configured. Also, try to disable this option,  if you are getting

• Client request get a read timed out error
• "Request Entity Too Large" appears with The BEA-380000 error in the logs
• "Request Entity Too Large" appears with the http status code 413 error in the logs (OSB 12c)
• The last executed OSB instance continuously retries every 5 minutes

If you disable "Checked Streaming Mode"  OSB may double invoke target system for a single invocation.  Also, Quality of Service attribute of Proxy Service default behavior of "Exactly Once" is affected. To fix, you need to check on "Quality of Service" attribute to make it as "Exactly Once" for the -message flow -route node of a proxy service.

As of OSB 12c, oracle HTTP Server 12c is bundeled with Oracle SOA Suite12c and recommended as part of enterprise deployment guide provided by Oracle, we need to disable the chunked streaming mode case by case.  If the business service end point is SOAP based service,  most probably SOAP end point does not require payload in chunks.