2.2 KiB
| title | name | editor | contributors |
|---|---|---|---|
| WAKU-STORE-SYNC | Waku Store Synchronization | Simon-Pierre Vivier <simvivier@status.im> |
Abstract
This document describe the strategy Waku Store node will employ to stay synchronized. The goal being that all store nodes eventually archive the same set of messages.
Background / Rationale / Motivation
Message propagation in the network is not perfect, even with GossipSub mechanisms to detect missed messages. Nodes can also go offline for various reason outside our control. Store nodes that want to provide a good service must be able to remedy situations like these. By having store nodes syncronize with each other through various protocols, the set of archived messages network wide will be eventually consistent.
Theory / Semantics
The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “NOT RECOMMENDED”, “MAY”, and “OPTIONAL” in this document are to be interpreted as described in RFC 2119.
Various protocols and features that help with message consistency are described below.
Store Resume
This feature allow a node to fill the gap in messages for the period it was last offline. At startup, a node use the Store protocol to query a random node for the time interval since it was last online. Messages returned my the query are then added to the node local archive storage. It is RECOMMENDED” to limit the time interval to a maximum of 6 hours.
Waku Sync
Nodes that stay online can still miss messages. [Waku Sync](TODO link to spec) is the protocol used to find those messages by periodically syncing with random nodes. It is RECOMMENDED to trigger a sync every 5 minutes for a time range of the last hour. After both message hash sets are reconciled, the Store protocol is used to reciprocally query the other node with the message hash differences found. Messages returned my the query are then added to the node local Waku sync and archive storage.
Copyright
Copyright and related rights waived via CC0.
References
- [Waku Sync](TODO link to spec)