Java CAPS 5.1 and Java CAPS 6 - Streaming Large FTP Transfers
By Michael.Czapski on Apr 06, 2008
Transferring large payloads, on the order of tens or hundreds of megabytes, between a FTP server and a local file system, in either direction, requires selection of appropriate features of the Batch FTP and Batch Local File eWays, and tuning certain timing parameters.
Default timing parameter values result in timeout exceptions when transferring large payloads.
The Batch FTP eWay and the Batch Local File eWas are typically used to receive the entire payload before writing it out. This results in attempts to allocate memory many time the size of the payload being transferred and, for large files, causes memory exhaustion and application server failures.
Discussion in the attached document points out which timing parameters need to be tuned to facilitate transfer of large payloads. It also presents sample Java code that uses facilities of the Batch FTP and Batch Local File for streaming payload between the FTP server and the local file systems without using excessive amount of memory.
The material covered in the document was prepared using Java CAPS projects developed and tested in Java CAPS 5.1.0, exported, imported into Java CAPS Release 6 and tested again. It is expected that the code will work in all versions of Java CAPS from 5.1.0 up.