Connecting to HTTP(S) Servers
You can configure HTTP(S) servers in events and virtual folders. When connecting to remote HTTP(S) servers, ActiveTransfer works differently if the HTTP(S) server is an ActiveTransfer Server or a third-party HTTP(S) server as follows:
Third-party HTTP(S) server. When connecting to third-party HTTP(S) servers, ActiveTransfer supports only upload and download file operations. Typically, third party HTTP(S) servers do not support operations like file listing, renaming, moving, and so on. Due to this limitation, you cannot specify a third-party HTTP(S) servers in the virtual folder configuration, since virtual folders require support for all file operations.
However, you can specify a third party HTTP(S) server in an event for find and copy actions. If you use a third-party HTTP(S) server in an event action, the HTTP(S) URL specified in the action relates to a single file. Therefore, the event action works on a single file at a time.
ActiveTransfer HTTP(S) Server. ActiveTransfer uses a custom method to communicate between each other using an agreed set of HTTP requests and response. Therefore, when ActiveTransfer connects to an ActiveTransfer HTTP(S) Server, all file operations are supported.
Connections to remote HTTP(S) servers also support the following features:
Streaming of data (chunking). ActiveTransfer supports chunked transfer encoding in HTTP. In chunked transfer encoding, the data is sent as a series of "chunks". This enables ActiveTransfer to stream the data to an HTTP(S) server rather than sending the data in a single HTTP request, which is particularly helpful when handling large files. The Active transfer client streams the data to the server as soon as the data is available without waiting for the complete data to be available.
For upload or download, there is no limitation on the file size. However, the chunk size is determined by the Integration Server property watt.net.httpChunkSize and the default value is 8192. For details, see the webMethods Integration Server Administrator’s Guide.
If the remote HTTP(S) server streams the file data that ActiveTransfer must download, ActiveTransfer downloads the file as chunks. File uploads presume that the HTTP(S) servers support chunking. ActiveTransfer sends the file data as chunks if you include the upload header Transfer-Encoding with the value chunked in the event configuration.
Multipart messages. HTTP(S) servers expect data formatted as multipart messages. ActiveTransfer supports multipart messages out of the box for file upload to remote HTTP(S) servers. To send files formatted as multipart messages, include the upload header
Content-Type with the value
multipart/form-data in the event configuration.
Resuming file transfer from point of interruption. When an upload or download operation fails while ActiveTransfer connects to an HTTP(S) server, ActiveTransfer resumes the operation from the point where the failure occurred. ActiveTransfer transfers (upload or download) only the remaining data (bytes) and skips the data that is already transferred.