Data stewardship

[Eknir]

Epic

Story

As a supporter of specific content on Swarm, I want to contribute to keeping this data alive, such that others can download it as well

Background

It is in the nature of Swarm that data eventually disappears. If content does not get downloaded and your postage stamps (#1440) expire, then the content will be deleted by the storer nodes. While the network is receiving frequent updates and the Swarm team is ironing out any quirks in the network, it may also happen that content disappears even though it is frequently accessed and/or has a valid postage stamp.
As a supporter of specific content (or the original uploader), you want to do everything you can to ensure that the data stays available.
Swarm already support local pinning, which ensures persistence of the data on the node itself. In order to have the data also visible by other nodes, the data should reside at it's natural location in the network. Data stewards are there to ensure that the data is available in the network.
Local pinners can become data stewards if they:

1. can query the network for the availability of their locally-pinned content
2. when the content is not available => re-upload (possibly adding new funds to the postage batch)

Relation with the Global Pinning feature

Data stewardship is related to global pinning, where global pinning is essentially a paradigm where content downloaders can warn local pinners of data being unavailable and thus triggering the pinner to reupload. With data stewardship, content pinners proactively try to find out the availability of the data in the network themselves and take action whenever they find out that it is unavailable.

Status

✅ local pinning
🗓️ Get current pins, find out status in the network, re-upload: #1302, #1051, #852
🧠 ethersphere/swarm-cli#65