micro/client/selector/strategy.go
Vasiliy Tolstov f23638c036 fix import paths for v2 release
Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
2020-01-30 14:44:40 +03:00

57 lines
1.0 KiB
Go

package selector
import (
"math/rand"
"sync"
"time"
"github.com/micro/go-micro/v2/registry"
)
func init() {
rand.Seed(time.Now().UnixNano())
}
// Random is a random strategy algorithm for node selection
func Random(services []*registry.Service) Next {
nodes := make([]*registry.Node, 0, len(services))
for _, service := range services {
nodes = append(nodes, service.Nodes...)
}
return func() (*registry.Node, error) {
if len(nodes) == 0 {
return nil, ErrNoneAvailable
}
i := rand.Int() % len(nodes)
return nodes[i], nil
}
}
// RoundRobin is a roundrobin strategy algorithm for node selection
func RoundRobin(services []*registry.Service) Next {
nodes := make([]*registry.Node, 0, len(services))
for _, service := range services {
nodes = append(nodes, service.Nodes...)
}
var i = rand.Int()
var mtx sync.Mutex
return func() (*registry.Node, error) {
if len(nodes) == 0 {
return nil, ErrNoneAvailable
}
mtx.Lock()
node := nodes[i%len(nodes)]
i++
mtx.Unlock()
return node, nil
}
}