| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package maglev |
| |
| import ( |
| "github.com/apache/dubbo-go-pixiu/pkg/cluster/loadbalancer" |
| "github.com/apache/dubbo-go-pixiu/pkg/cluster/loadbalancer/ringhash" |
| "github.com/apache/dubbo-go-pixiu/pkg/logger" |
| "github.com/apache/dubbo-go-pixiu/pkg/model" |
| ) |
| |
| func init() { |
| loadbalancer.RegisterLoadBalancer(model.LoadBalancerMaglevHashing, MaglevHash{}) |
| loadbalancer.RegisterConsistentHashInit(model.LoadBalancerMaglevHashing, NewMaglevHash) |
| } |
| |
| func NewMaglevHash(config model.ConsistentHash, endpoints []*model.Endpoint) model.LbConsistentHash { |
| hosts := make([]string, len(endpoints)) |
| for i, endpoint := range endpoints { |
| hosts[i] = endpoint.GetHost() |
| } |
| |
| h, err := NewLookUpTable(config.MaglevTableSize, hosts) |
| if err == nil { |
| h.Populate() |
| return h |
| } |
| |
| logger.Infof("[dubbo-go-pixiu] maglev hash load balancing fail: %v, using ring hash instead", err) |
| if config.ReplicaNum == 0 { |
| config.ReplicaNum = 2 * len(endpoints) |
| } |
| return ringhash.NewRingHash(config, endpoints) |
| } |
| |
| type MaglevHash struct{} |
| |
| func (m MaglevHash) Handler(c *model.ClusterConfig, policy model.LbPolicy) *model.Endpoint { |
| dst, err := c.ConsistentHash.Hash.Get(policy.GenerateHash()) |
| if err != nil { |
| logger.Warnf("[dubbo-go-pixiu] error of getting from maglev hash: %v", err) |
| return nil |
| } |
| |
| endpoints := c.GetEndpoint(true) |
| |
| for _, endpoint := range endpoints { |
| if endpoint.GetHost() == dst { |
| return endpoint |
| } |
| } |
| |
| if len(endpoints) == 0 { |
| return nil |
| } |
| |
| return endpoints[0] |
| } |