Convey

Event-driven, layer 4 load balancer with dynamic configuration loading

Features

• Event-driven TCP load balancer built on tokio.
• Weighted round-robin load balancing. For uniform round robin simply leave out the weights or set them to be equal.
• Stats page (at /stats) with basic connection/bytes counters and backend server pool statuses
• Dynamic configuration re-loading of backend servers and associated weights. Configuration is loaded via a .toml file (see sample.toml for a full example).
• Tcp-based health checking of backend servers at a configured interval. If a server fails its health check it will be automatically removed from selection and added back once its health checks are successful.

Usage

Convey 0.1.0

Usage:
  convey
  convey --config=<config_file>
  convey (-h | --help)
  convey (-v | --version)

Options:
  -h, --help               Show this screen.
  --config=<config_file>   Config file location [default config.toml].
  -v, --version            Show version.

Passthrough mode

For passthrough and dsr
sudo iptables -t raw -A PREROUTING -p tcp --sport 8080 --dport 32768:61000 -j DROP

Only for passthrough
sudo iptables -A OUTPUT -p tcp --tcp-flags RST RST --dport 8000:8090 -j DROP

Required on backend servers for dsr to work
sudo tc qdisc add dev enp0s8 root handle 10: htb

sudo tc filter add dev enp0s8 parent 10: protocol ip prio 1 u32 match ip src 192.168.1.117 match ip sport 3000 0xffff match ip dst 192.168.1.136 action ok

sudo tc filter add dev enp0s8 parent 10: protocol ip prio 10 u32 match ip src 192.168.1.117 match ip sport 3000 0xffff action nat egress 192.168.1.117 192.168.1.136