func BenchmarkDefaultLoadBalancer(b *testing.B) {
discovery := dnsdisco.NewDiscovery("jabber", "tcp", "registro.br")
discovery.SetHealthChecker(dnsdisco.HealthCheckerFunc(func(target string, port uint16, proto string) (ok bool, err error) {
return true, nil
}))
discovery.SetRetriever(dnsdisco.RetrieverFunc(func(service, proto, name string) ([]*net.SRV, error) {
return []*net.SRV{
{
Target: "server1.example.com.",
Port: 1111,
Weight: 10,
Priority: 20,
},
{
Target: "server2.example.com.",
Port: 2222,
Weight: 70,
Priority: 10,
},
{
Target: "server3.example.com.",
Port: 3333,
Weight: 100,
Priority: 20,
},
{
Target: "server4.example.com.",
Port: 4444,
Weight: 1,
Priority: 15,
},
{
Target: "server5.example.com.",
Port: 5555,
Weight: 40,
Priority: 60,
},
}, nil
}))
// Retrieve the servers
if err := discovery.Refresh(); err != nil {
fmt.Println(err)
return
}
for i := 0; i < b.N; i++ {
discovery.Choose()
}
}
// ExampleHealthCheckerFunc tests HTTP fetching the homepage and checking the
// HTTP status code.
func ExampleHealthCheckerFunc() {
discovery := dnsdisco.NewDiscovery("http", "tcp", "pantz.org")
discovery.SetHealthChecker(dnsdisco.HealthCheckerFunc(func(target string, port uint16, proto string) (ok bool, err error) {
response, err := http.Get("http://www.pantz.org")
if err != nil {
return false, err
}
return response.StatusCode == http.StatusOK, nil
}))
// Retrieve the servers
if err := discovery.Refresh(); err != nil {
fmt.Println(err)
return
}
target, port := discovery.Choose()
fmt.Printf("Target: %s\nPort: %d\n", target, port)
// Output:
// Target: www.pantz.org.
// Port: 80
}
Target: "server3.example.com.",
Port: 3333,
Priority: 15,
Weight: 20,
},
{
Target: "server4.example.com.",
Port: 4444,
Priority: 10,
Weight: 10,
},
}, nil
})
}(),
healthChecker: dnsdisco.HealthCheckerFunc(func(target string, port uint16, proto string) (ok bool, err error) {
return true, nil
}),
},
{
description: "it should fail to retrieve the SRV records",
service: "jabber",
proto: "tcp",
name: "registro.br",
expectedTarget: "server1.example.com.",
expectedPort: 1111,
refreshInterval: 100 * time.Millisecond,
retriever: func() dnsdisco.RetrieverFunc {
calls := 0
return dnsdisco.RetrieverFunc(func(service, proto, name string) ([]*net.SRV, error) {
calls++
if calls == 1 {
{
Target: "server1.example.com.",
Port: 1111,
Priority: 10,
Weight: 20,
},
{
Target: "server2.example.com.",
Port: 2222,
Priority: 10,
Weight: 10,
},
}, nil
}),
healthChecker: dnsdisco.HealthCheckerFunc(func(target string, port uint16, proto string) (ok bool, err error) {
return target == "server2.example.com.", nil
}),
expectedTarget: "server2.example.com.",
expectedPort: 2222,
},
{
description: "it should fallback to other priority group by health check",
service: "jabber",
proto: "tcp",
name: "registro.br",
retriever: dnsdisco.RetrieverFunc(func(service, proto, name string) ([]*net.SRV, error) {
return []*net.SRV{
{
Target: "server1.example.com.",
Port: 1111,
Priority: 10,