9 releases (5 breaking)
0.6.1 | Aug 6, 2021 |
---|---|
0.6.0 | Jan 11, 2021 |
0.5.0 | May 2, 2020 |
0.4.0 | Apr 15, 2019 |
0.1.0 | Dec 11, 2018 |
#3 in #kademlia
40 downloads per month
Used in dsf-daemon
105KB
2.5K
SLoC
rust-kad
A generic / futures based implementation of the Kademlia DHT, heavily inspired by dtantsur/rust-dht with the goal of providing a simple to use, well-tested, low-dependency, futures-based API for using DHTs with arbitrary communication mechanisms and encodings
Usage
Configuration
- k - system wide replication parameter, defines bucket sizes and search breadth
- concurrency - system wide concurrency parameter, number of parallel operations to run at once
Status
Work In Progress
Components
-
Receive message
- Update appropriate k-bucket
- Add node if bucket not full
- Store pending if bucket full and ping oldest (if > seen time)
- Respond to Ping with NoResult
- Respond to FindNodes with NodesFound
- Respond to FindValues with NodesFound or ValuesFound
- For new node, Send STORE RPC if own ID is closer to key than known nearby nodes
- Update appropriate k-bucket
-
Search - common to most operations
- Select alpha closest nodes
- Send RPCs to selected subset of nodes
- If no suitable responses, expand to k closest nodes
- Recurse until responses received from k closest nodes
-
Find Node
- Search using FIND_NODE RPC
- Return node
-
Find Value
- Search using FIND_VALUE RPC
- Collect values
- Once values returned, store (k, v) pair at the closest node observed that did not return the value
-
Store Value
- Search using FIND_NODE RPC
- Send STORE RPC to k closest nodes
-
Connect
- Insert known node into appropriate k-bucket
- Perform Find Node lookup on own ID
- Refresh all k-buckets further than the closest neighbor
-
Maintanence
- Remove non-responsive / old contacts
- Expire values
- Basic expiry after defined time
- Cache expiry exponentially inversely proportional to number of nodes between current node and closest to key ID node
- Refresh k-buckets
- FIND_NODES to random ID in any bucket not queried in a configurable period
- Re-publish values
- STORE RPC to K nodes at defined period (hourly)
- Unless a STORE RPC has been received in the same period
-
Buckets
- Implement bucket splitting (if it can be done more efficiently than existing?)
- Useful for maintenance / don't need to message unused buckets
- Reverse / generate random IDs in bucket for maintenance purposes
- Implement bucket splitting (if it can be done more efficiently than existing?)
Questions
- How is FindValues usually handled where there can be more than one value per ID?
- Is there a case when STORE is valid when the origin ID is closer to the requester ID than the local ID?
- This seems like it could be ignored
Dependencies
~6MB
~101K SLoC