Support for string/errors

[mitar]

I was thinking that all errors nodes had could be stored as datastream as well. So we could then display them as discrete events in visualizations. This would then make debugging easier. We could make fake stream in django-datastream which would read from the relational database, or we could simply store all errors into datastream to begin with.

So I imagine then support for data type which would be or list of strings or maybe list of simple JSON-able objects? (You can have multiple errors at a given moment.) I would go for JSON-able objects because you can then have more metadata about the error, not just string.

Downsampling would be simple as well, we would probably support only min, max and sum for this datatype (maybe I missed some). min is the first object (list of one object) in the concatenation of all objects, sum is a concatenation of all objects, max is the last object (list of one object). Ah, and we can support count. Do we count number of datapoints or number of all objects in all datapoints?

[kostko]

I would go for list of simple JSON-able objects. And in case of nodewatcher, we could write a special event sink that would store events as datapoints in such a stream.

[mitar]

Yes, I agree.