Services and targets

A service describes one upstream application. A target is a server that can handle requests for that service.

Service fields

Field	Purpose	Default
name	Unique operator-facing name	required
protocol	Upstream http or https	http
connect_timeout_ms	TCP and TLS connection timeout	5000
read_timeout_ms	Upstream response timeout	60000
write_timeout_ms	Upstream request timeout	60000
retries	Retry count	1
lb_algorithm	Target selection strategy	round_robin
tls_sni	SNI sent to HTTPS upstreams	target host
health_path	HTTP path for active checks	TCP connection check

Target fields

Field	Purpose	Default
host	IP address or DNS name	required
port	Upstream port	required
weight	Share used by weighted balancing	100
enabled	Whether the target may receive traffic	true

Load balancing

• round_robin rotates through healthy targets.
• weighted gives targets traffic in proportion to their weight values.
• random chooses a healthy target at random.
• consistent hashes the client IP so the same client usually reaches the same target.

Raahi sends traffic only to targets that are enabled and healthy.

Health checks

Without health_path, Raahi opens a TCP connection to test the target. With health_path, it sends an HTTP GET and accepts a 2xx or 3xx response. Checks for HTTPS services verify the upstream certificate.

A hostname may resolve to several addresses. Raahi tests each address and uses one that works. It refreshes DNS every 30 seconds and keeps the previous addresses if a lookup fails.

HTTP proxying, TCP proxying, and health checks use the same selected address. A failed proxy connection removes the target before the next scheduled health check.

Check the current state of every target:

curl http://127.0.0.1:9080/api/v1/health