Availability and distribution

Peer-to-peer availability is not automatic. A new user can only download data that at least one online peer already holds. Pear applications therefore need an explicit strategy for data availability and application availability.

Two availability problems

Data availability

Data availability means the Hypercores, Autobases, or drives your application reads and writes remain reachable on the swarm. Chat history, shared documents, and room state all depend on someone seeding the relevant cores.

Application availability

Application availability means the Pear app itself—its metadata core and content Hyperdrive—can be discovered and installed. A pear:// link is stable, but the bytes behind it still have to exist on at least one peer.

Both problems share the same underlying constraint: replication requires a live source.

Seeding with pear seed

The simplest way to keep an application bundle online is seeding, analogous to seeding a torrent. Running pear seed pear://<app> keeps the underlying cores announced and available for download.

pear seed pear://<app>

The process must stay running while you want to act as a guaranteed source. Anyone can open the link, but a first-time user needs at least one seeder with a complete copy.

Seeding works well when you control an always-on machine and the cores you care about are ones you already possess. It has two practical limits:

1. Operational overhead—You need a running pear (or equivalent replicator) per application you seed.
2. Scope—You can only seed cores you have locally. A private room or direct-message thread you are not a member of cannot be seeded from your node.

When authors go offline and no participant keeps seeding, data can become temporarily unreachable even though the cryptographic keys still exist.

Finding the keys to keep available

pear info pear://<app> prints the keys behind an application bundle:

pear info pear://<app>

The project and content rows identify the metadata core and content drive. To keep them available, open the corresponding cores in a replicator process—either your own pear seed process above, or a third-party blind peer you register them with.

See also

• Storage and distribution—on-disk layout and the pear seed distribution model.
• Deploy your application—staging and announcing releases.
• Blind peering—a third-party replication service that keeps your cores available without decrypting them.
• Peer-to-peer, demystified—how peers find one another on the swarm.