OneM2M: Get Notification once a file loads on FTP server

Question

I have a device that sends data to a FTP server. In OM2M, I want to implement an IPE to access this data and send it to MN-CSE.

Currently I am fresher on oneM2M standards And as per the below reference I found the 2 alternative for this task.

1. The ftp server notifies your AE (it is constrained for us to not to make any change on FTP server configuration so we are unable to go with this approach)

2. Your AE implements the ftp server and would then be able to directly react on new data events.

Here I just want to adopt the second approach so if possible can I get any reference so that I can proceed with that as there is not such documentation available that I found on Internet. Or kindly mention if there is any other approach that best suits to oneM2M standard for this issue.

And I just want to get confirmation that if we are monitoring FTP server periodically for the incoming input file and then process them and send them to MN-CSE then whether this approach suits to oneM2M standards or not ??

OneM2M: IPE that periodically fetches device data from FTP server

Answer 1

This question is indeed about different integration options. In general, it is one or more Application Entities (AE) that operate with the resources / data in a CSE. Every tool, application, protocol gateway, or "adaptor" is, from oneM2M perspective, an AE.

A special form of AE is the IPE, the Interworking Proxy Entity. It is used to connected another system or infrastructure to a CSE and mediate between these two worlds. The CSE part, ie. the protocol and the data formats etc, are covered by the oneM2M specification, and the other part must then implement the other protocol and technical specifications. The actual task is then to convert the data and expected behaviour between both worlds.

I am not sure from your description whether what you are planning is such a protocol "gateways", or just push the data received via an ftp server to a CSE. But technically, this doesn't matter much for the oneM2M part: You need to define how the data is structured on the CSE etc anyway.

For the data retrieval: As you mention in your question there is a third option to the other two:

3. The AE monitors an external system for new or updated resources, and pushes them to the CSE as soon as when they are ready.

From oneM2M's perspective this is completely fine. Technically you must make sure how to find out when the data is new, completely received, still valid, etc. ... basically all the challenges when you are polling resources. The first two options would be more helpful because you would avoid some of the problems that come with polling, but as you wrote sometimes you just don't have control about the system you want to connect to.