CDF Extractors

I have to build two 2 types of extractors.

1. PI extractor to connect to the PI server and fetch the data and ingest into CDF

2. SharePoint online - Extract data from files present in SharePoint online and ingest into CDF.

I wanted to know the construct in building the extractors. Mainly wanted to account for scenarios where the PI server is not available and PI extractor is unable to fetch the data from the pipeline. How to handle these kinds of situations and incorporate them in the code while building the extractor. Also, how to handle monitoring while performing extractor. Are there some sample code repos that can be referenced for getting complete idea for building extractors.