hedge_rs 0.1.6

hedge-rs

A cluster membership Rust library. It is built on spindle-rs, a distributed locking library built on Cloud Spanner and TrueTime. It is a port (subset only) of the original hedge, which is written in Go. Ported features include:

• Tracking of member nodes - good for clusters with sizes that can change dynamically overtime, such as GCP MIGs, and Kubernetes Deployments;
• Leader election - the cluster elects and maintains a single leader node at all times;
• List of members - get a list of all member nodes at any time;
• Send - any member node can send messages to the leader at any time; and
• Broadcast - any member node can broadcast messages to all nodes at any time.

Running the sample

First, create the Spanner table for spindle-rs:

CREATE TABLE locktable (
    name STRING(MAX) NOT NULL,
    heartbeat TIMESTAMP OPTIONS (allow_commit_timestamp=true),
    token TIMESTAMP OPTIONS (allow_commit_timestamp=true),
    writer STRING(MAX),
) PRIMARY KEY (name)

Then you can run the sample like so:

# Clone and build:
$ git clone https://github.com/flowerinthenight/hedge-rs/
$ cd hedge-rs/
$ cargo build

# Run the first instance:
# (Use your actual values)
$ RUST_LOG=info,spindle_rs=off ./target/debug/example \
  projects/p/instances/i/databases/db \
  locktable \
  0.0.0.0:8080

# Run this 2nd instance on a different terminal:
# (Use your actual values)
$ RUST_LOG=info,spindle_rs=off ./target/debug/example \
  projects/p/instances/i/databases/db \
  locktable \
  0.0.0.0:8081

# Run this 3nd instance on a different terminal:
# (Use your actual values)
$ RUST_LOG=info,spindle_rs=off ./target/debug/example \
  projects/p/instances/i/databases/db \
  locktable \
  0.0.0.0:8082

You can play around by adding more processes, killing the leader process, killing a non-leader process, restarting an existing process, etc. You can also remove the spindle_rs=off environment to see logs from spindle-rs.