xds: balancer group (#2564)
balancerGroup takes a list of balancers, and make then into one balancer.
Updates from ClientConn are forwarded to sub-balancers
- service config update
- Not implemented currently
- address update
- subConn state change
- find the corresponding balancer and forward
Actions from sub-balances are forwarded to parent ClientConn
- new/remove SubConn
- picker update and health states change
- sub-pickers are grouped into a group-picker
- aggregated connectivity state is the overall state of all pickers.
- resolveNow
This commit is contained in:
Menghan Li
337
balancer/xds/edsbalancer/balancergroup.go
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337
balancer/xds/edsbalancer/balancergroup.go
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@ -0,0 +1,337 @@
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/*
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* Copyright 2019 gRPC authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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// TODO: move package comment to edsbalancer.go.
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// Package edsbalancer implements balancer generated from an eds response.
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package edsbalancer
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import (
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"context"
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"sync"
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"google.golang.org/grpc/balancer"
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"google.golang.org/grpc/balancer/base"
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"google.golang.org/grpc/connectivity"
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"google.golang.org/grpc/grpclog"
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"google.golang.org/grpc/resolver"
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)
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type pickerState struct {
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weight uint32
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picker balancer.Picker
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state connectivity.State
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}
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// balancerGroup takes a list of balancers, and make then into one balancer.
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//
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// Note that this struct doesn't implement balancer.Balancer, because it's not
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// intended to be used directly as a balancer. It's expected to be used as a
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// sub-balancer manager by a high level balancer.
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//
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// Updates from ClientConn are forwarded to sub-balancers
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// - service config update
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// - Not implemented
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// - address update
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// - subConn state change
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// - find the corresponding balancer and forward
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//
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// Actions from sub-balances are forwarded to parent ClientConn
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// - new/remove SubConn
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// - picker update and health states change
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// - sub-pickers are grouped into a group-picker
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// - aggregated connectivity state is the overall state of all pickers.
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// - resolveNow
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type balancerGroup struct {
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cc balancer.ClientConn
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mu sync.Mutex
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idToBalancer map[string]balancer.Balancer
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scToID map[balancer.SubConn]string
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pickerMu sync.Mutex
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// All balancer IDs exist as keys in this map. If an ID is not in map, it's
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// either removed or never added.
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idToPickerState map[string]*pickerState
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}
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func newBalancerGroup(cc balancer.ClientConn) *balancerGroup {
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return &balancerGroup{
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cc: cc,
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scToID: make(map[balancer.SubConn]string),
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idToBalancer: make(map[string]balancer.Balancer),
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idToPickerState: make(map[string]*pickerState),
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}
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}
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// add adds a balancer built by builder to the group, with given id and weight.
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func (bg *balancerGroup) add(id string, weight uint32, builder balancer.Builder) {
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bg.mu.Lock()
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if _, ok := bg.idToBalancer[id]; ok {
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bg.mu.Unlock()
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grpclog.Warningf("balancer group: adding a balancer with existing ID: %s", id)
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return
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}
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bg.mu.Unlock()
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bgcc := &balancerGroupCC{
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id: id,
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group: bg,
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}
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b := builder.Build(bgcc, balancer.BuildOptions{})
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bg.mu.Lock()
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bg.idToBalancer[id] = b
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bg.mu.Unlock()
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bg.pickerMu.Lock()
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bg.idToPickerState[id] = &pickerState{
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weight: weight,
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// Start everything in IDLE. It's doesn't affect the overall state
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// because we don't count IDLE when aggregating (as opposite to e.g.
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// READY, 1 READY results in overall READY).
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state: connectivity.Idle,
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}
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bg.pickerMu.Unlock()
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}
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// remove removes the balancer with id from the group, and closes the balancer.
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//
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// It also removes the picker generated from this balancer from the picker
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// group. It always results in a picker update.
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func (bg *balancerGroup) remove(id string) {
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bg.mu.Lock()
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// Close balancer.
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if b, ok := bg.idToBalancer[id]; ok {
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b.Close()
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delete(bg.idToBalancer, id)
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}
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// Remove SubConns.
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for sc, bid := range bg.scToID {
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if bid == id {
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bg.cc.RemoveSubConn(sc)
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delete(bg.scToID, sc)
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}
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}
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bg.mu.Unlock()
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bg.pickerMu.Lock()
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// Remove id and picker from picker map. This also results in future updates
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// for this ID to be ignored.
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delete(bg.idToPickerState, id)
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// Update state and picker to reflect the changes.
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bg.cc.UpdateBalancerState(buildPickerAndState(bg.idToPickerState))
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bg.pickerMu.Unlock()
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}
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// changeWeight changes the weight of the balancer.
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//
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// NOTE: It always results in a picker update now. This probably isn't
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// necessary. But it seems better to do the update because it's a change in the
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// picker (which is balancer's snapshot).
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func (bg *balancerGroup) changeWeight(id string, newWeight uint32) {
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bg.pickerMu.Lock()
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defer bg.pickerMu.Unlock()
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pState, ok := bg.idToPickerState[id]
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if !ok {
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return
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}
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if pState.weight == newWeight {
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return
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}
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pState.weight = newWeight
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// Update state and picker to reflect the changes.
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bg.cc.UpdateBalancerState(buildPickerAndState(bg.idToPickerState))
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}
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// Following are actions from the parent grpc.ClientConn, forward to sub-balancers.
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// SubConn state change: find the corresponding balancer and then forward.
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func (bg *balancerGroup) handleSubConnStateChange(sc balancer.SubConn, state connectivity.State) {
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grpclog.Infof("balancer group: handle subconn state change: %p, %v", sc, state)
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bg.mu.Lock()
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var b balancer.Balancer
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if id, ok := bg.scToID[sc]; ok {
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if state == connectivity.Shutdown {
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// Only delete sc from the map when state changed to Shutdown.
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delete(bg.scToID, sc)
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}
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b = bg.idToBalancer[id]
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}
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bg.mu.Unlock()
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if b == nil {
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grpclog.Infof("balancer group: balancer not found for sc state change")
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return
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}
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b.HandleSubConnStateChange(sc, state)
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}
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// Address change: forward to balancer.
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func (bg *balancerGroup) handleResolvedAddrs(id string, addrs []resolver.Address) {
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bg.mu.Lock()
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b, ok := bg.idToBalancer[id]
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bg.mu.Unlock()
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if !ok {
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grpclog.Infof("balancer group: balancer with id %q not found", id)
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return
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}
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b.HandleResolvedAddrs(addrs, nil)
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}
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// TODO: handleServiceConfig()
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//
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// For BNS address for slicer, comes from endpoint.Metadata. It will be sent
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// from parent to sub-balancers as service config.
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// Following are actions from sub-balancers, forward to ClientConn.
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// newSubConn: forward to ClientConn, and also create a map from sc to balancer,
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// so state update will find the right balancer.
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//
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// One note about removing SubConn: only forward to ClientConn, but not delete
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// from map. Delete sc from the map only when state changes to Shutdown. Since
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// it's just forwarding the action, there's no need for a removeSubConn()
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// wrapper function.
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func (bg *balancerGroup) newSubConn(id string, addrs []resolver.Address, opts balancer.NewSubConnOptions) (balancer.SubConn, error) {
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sc, err := bg.cc.NewSubConn(addrs, opts)
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if err != nil {
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return nil, err
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}
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bg.mu.Lock()
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bg.scToID[sc] = id
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bg.mu.Unlock()
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return sc, nil
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}
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// updateBalancerState: create an aggregated picker and an aggregated
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// connectivity state, then forward to ClientConn.
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func (bg *balancerGroup) updateBalancerState(id string, state connectivity.State, picker balancer.Picker) {
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grpclog.Infof("balancer group: update balancer state: %v, %v, %p", id, state, picker)
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bg.pickerMu.Lock()
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defer bg.pickerMu.Unlock()
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pickerSt, ok := bg.idToPickerState[id]
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if !ok {
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// All state starts in IDLE. If ID is not in map, it's either removed,
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// or never existed.
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grpclog.Infof("balancer group: pickerState not found when update picker/state")
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return
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}
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pickerSt.picker = picker
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pickerSt.state = state
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bg.cc.UpdateBalancerState(buildPickerAndState(bg.idToPickerState))
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}
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func (bg *balancerGroup) close() {
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bg.mu.Lock()
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for _, b := range bg.idToBalancer {
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b.Close()
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}
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bg.mu.Unlock()
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}
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func buildPickerAndState(m map[string]*pickerState) (connectivity.State, balancer.Picker) {
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var readyN, connectingN int
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readyPickerWithWeights := make([]pickerState, 0, len(m))
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for _, ps := range m {
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switch ps.state {
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case connectivity.Ready:
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readyN++
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readyPickerWithWeights = append(readyPickerWithWeights, *ps)
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case connectivity.Connecting:
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connectingN++
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}
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}
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var aggregatedState connectivity.State
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switch {
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case readyN > 0:
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aggregatedState = connectivity.Ready
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case connectingN > 0:
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aggregatedState = connectivity.Connecting
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default:
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aggregatedState = connectivity.TransientFailure
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}
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if aggregatedState == connectivity.TransientFailure {
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return aggregatedState, base.NewErrPicker(balancer.ErrTransientFailure)
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}
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return aggregatedState, newPickerGroup(readyPickerWithWeights)
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}
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type pickerGroup struct {
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readyPickerWithWeights []pickerState
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length int
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mu sync.Mutex
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idx int // The index of the picker that will be picked
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count uint32 // The number of times the current picker has been picked.
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}
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// newPickerGroup takes pickers with weights, and group them into one picker.
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//
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// Note it only takes ready pickers. The map shouldn't contain non-ready
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// pickers.
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//
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// TODO: (bg) confirm this is the expected behavior: non-ready balancers should
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// be ignored when picking. Only ready balancers are picked.
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func newPickerGroup(readyPickerWithWeights []pickerState) *pickerGroup {
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return &pickerGroup{
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readyPickerWithWeights: readyPickerWithWeights,
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length: len(readyPickerWithWeights),
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}
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}
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func (pg *pickerGroup) Pick(ctx context.Context, opts balancer.PickOptions) (conn balancer.SubConn, done func(balancer.DoneInfo), err error) {
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if pg.length <= 0 {
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return nil, nil, balancer.ErrNoSubConnAvailable
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}
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// TODO: the WRR algorithm needs a design.
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// MAYBE: move WRR implmentation to util.go as a separate struct.
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pg.mu.Lock()
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pickerSt := pg.readyPickerWithWeights[pg.idx]
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p := pickerSt.picker
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pg.count++
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if pg.count >= pickerSt.weight {
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pg.idx = (pg.idx + 1) % pg.length
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pg.count = 0
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}
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pg.mu.Unlock()
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return p.Pick(ctx, opts)
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}
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// balancerGroupCC implements the balancer.ClientConn API and get passed to each
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// sub-balancer. It contains the sub-balancer ID, so the parent balancer can
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// keep track of SubConn/pickers and the sub-balancers they belong to.
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//
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// Some of the actions are forwarded to the parent ClientConn with no change.
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// Some are forward to balancer group with the sub-balancer ID.
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type balancerGroupCC struct {
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id string
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group *balancerGroup
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}
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func (bgcc *balancerGroupCC) NewSubConn(addrs []resolver.Address, opts balancer.NewSubConnOptions) (balancer.SubConn, error) {
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return bgcc.group.newSubConn(bgcc.id, addrs, opts)
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}
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func (bgcc *balancerGroupCC) RemoveSubConn(sc balancer.SubConn) {
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bgcc.group.cc.RemoveSubConn(sc)
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}
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func (bgcc *balancerGroupCC) UpdateBalancerState(state connectivity.State, picker balancer.Picker) {
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bgcc.group.updateBalancerState(bgcc.id, state, picker)
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}
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func (bgcc *balancerGroupCC) ResolveNow(opt resolver.ResolveNowOption) {
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bgcc.group.cc.ResolveNow(opt)
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}
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func (bgcc *balancerGroupCC) Target() string {
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return bgcc.group.cc.Target()
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}
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376
balancer/xds/edsbalancer/balancergroup_test.go
Normal file
376
balancer/xds/edsbalancer/balancergroup_test.go
Normal file
@ -0,0 +1,376 @@
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/*
|
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* Copyright 2019 gRPC authors.
|
||||
*
|
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* Licensed 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.
|
||||
*/
|
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|
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package edsbalancer
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import (
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"context"
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"reflect"
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"testing"
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"google.golang.org/grpc/balancer"
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"google.golang.org/grpc/balancer/roundrobin"
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"google.golang.org/grpc/connectivity"
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"google.golang.org/grpc/resolver"
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)
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var (
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rrBuilder = balancer.Get(roundrobin.Name)
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testBalancerIDs = []string{"b1", "b2", "b3"}
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testBackendAddrs = []resolver.Address{{Addr: "1.1.1.1:1"}, {Addr: "2.2.2.2:2"}, {Addr: "3.3.3.3:3"}, {Addr: "4.4.4.4:4"}}
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)
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// 1 balancer, 1 backend -> 2 backends -> 1 backend.
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func TestBalancerGroup_OneRR_AddRemoveBackend(t *testing.T) {
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cc := newTestClientConn(t)
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bg := newBalancerGroup(cc)
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// Add one balancer to group.
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bg.add(testBalancerIDs[0], 1, rrBuilder)
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// Send one resolved address.
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bg.handleResolvedAddrs(testBalancerIDs[0], testBackendAddrs[0:1])
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// Send subconn state change.
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sc1 := <-cc.newSubConnCh
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bg.handleSubConnStateChange(sc1, connectivity.Connecting)
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bg.handleSubConnStateChange(sc1, connectivity.Ready)
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|
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// Test pick with one backend.
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p1 := <-cc.newPickerCh
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for i := 0; i < 5; i++ {
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gotSC, _, _ := p1.Pick(context.Background(), balancer.PickOptions{})
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if !reflect.DeepEqual(gotSC, sc1) {
|
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t.Fatalf("picker.Pick, got %v, want %v", gotSC, sc1)
|
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}
|
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}
|
||||
|
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// Send two addresses.
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bg.handleResolvedAddrs(testBalancerIDs[0], testBackendAddrs[0:2])
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// Expect one new subconn, send state update.
|
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sc2 := <-cc.newSubConnCh
|
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bg.handleSubConnStateChange(sc2, connectivity.Connecting)
|
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bg.handleSubConnStateChange(sc2, connectivity.Ready)
|
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|
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// Test roundrobin pick.
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p2 := <-cc.newPickerCh
|
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want := []balancer.SubConn{sc1, sc2}
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if err := isRoundRobin(want, func() balancer.SubConn {
|
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sc, _, _ := p2.Pick(context.Background(), balancer.PickOptions{})
|
||||
return sc
|
||||
}); err != nil {
|
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t.Fatalf("want %v, got %v", want, err)
|
||||
}
|
||||
|
||||
// Remove the first address.
|
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bg.handleResolvedAddrs(testBalancerIDs[0], testBackendAddrs[1:2])
|
||||
scToRemove := <-cc.removeSubConnCh
|
||||
if !reflect.DeepEqual(scToRemove, sc1) {
|
||||
t.Fatalf("RemoveSubConn, want %v, got %v", sc1, scToRemove)
|
||||
}
|
||||
bg.handleSubConnStateChange(scToRemove, connectivity.Shutdown)
|
||||
|
||||
// Test pick with only the second subconn.
|
||||
p3 := <-cc.newPickerCh
|
||||
for i := 0; i < 5; i++ {
|
||||
gotSC, _, _ := p3.Pick(context.Background(), balancer.PickOptions{})
|
||||
if !reflect.DeepEqual(gotSC, sc2) {
|
||||
t.Fatalf("picker.Pick, got %v, want %v", gotSC, sc2)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// 2 balancers, each with 1 backend.
|
||||
func TestBalancerGroup_TwoRR_OneBackend(t *testing.T) {
|
||||
cc := newTestClientConn(t)
|
||||
bg := newBalancerGroup(cc)
|
||||
|
||||
// Add two balancers to group and send one resolved address to both
|
||||
// balancers.
|
||||
bg.add(testBalancerIDs[0], 1, rrBuilder)
|
||||
bg.handleResolvedAddrs(testBalancerIDs[0], testBackendAddrs[0:1])
|
||||
sc1 := <-cc.newSubConnCh
|
||||
|
||||
bg.add(testBalancerIDs[1], 1, rrBuilder)
|
||||
bg.handleResolvedAddrs(testBalancerIDs[1], testBackendAddrs[0:1])
|
||||
sc2 := <-cc.newSubConnCh
|
||||
|
||||
// Send state changes for both subconns.
|
||||
bg.handleSubConnStateChange(sc1, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc1, connectivity.Ready)
|
||||
bg.handleSubConnStateChange(sc2, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc2, connectivity.Ready)
|
||||
|
||||
// Test roundrobin on the last picker.
|
||||
p1 := <-cc.newPickerCh
|
||||
want := []balancer.SubConn{sc1, sc2}
|
||||
if err := isRoundRobin(want, func() balancer.SubConn {
|
||||
sc, _, _ := p1.Pick(context.Background(), balancer.PickOptions{})
|
||||
return sc
|
||||
}); err != nil {
|
||||
t.Fatalf("want %v, got %v", want, err)
|
||||
}
|
||||
}
|
||||
|
||||
// 2 balancers, each with more than 1 backends.
|
||||
func TestBalancerGroup_TwoRR_MoreBackends(t *testing.T) {
|
||||
cc := newTestClientConn(t)
|
||||
bg := newBalancerGroup(cc)
|
||||
|
||||
// Add two balancers to group and send one resolved address to both
|
||||
// balancers.
|
||||
bg.add(testBalancerIDs[0], 1, rrBuilder)
|
||||
bg.handleResolvedAddrs(testBalancerIDs[0], testBackendAddrs[0:2])
|
||||
sc1 := <-cc.newSubConnCh
|
||||
sc2 := <-cc.newSubConnCh
|
||||
|
||||
bg.add(testBalancerIDs[1], 1, rrBuilder)
|
||||
bg.handleResolvedAddrs(testBalancerIDs[1], testBackendAddrs[2:4])
|
||||
sc3 := <-cc.newSubConnCh
|
||||
sc4 := <-cc.newSubConnCh
|
||||
|
||||
// Send state changes for both subconns.
|
||||
bg.handleSubConnStateChange(sc1, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc1, connectivity.Ready)
|
||||
bg.handleSubConnStateChange(sc2, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc2, connectivity.Ready)
|
||||
bg.handleSubConnStateChange(sc3, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc3, connectivity.Ready)
|
||||
bg.handleSubConnStateChange(sc4, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc4, connectivity.Ready)
|
||||
|
||||
// Test roundrobin on the last picker.
|
||||
p1 := <-cc.newPickerCh
|
||||
want := []balancer.SubConn{sc1, sc2, sc3, sc4}
|
||||
if err := isRoundRobin(want, func() balancer.SubConn {
|
||||
sc, _, _ := p1.Pick(context.Background(), balancer.PickOptions{})
|
||||
return sc
|
||||
}); err != nil {
|
||||
t.Fatalf("want %v, got %v", want, err)
|
||||
}
|
||||
|
||||
// Turn sc2's connection down, should be RR between balancers.
|
||||
bg.handleSubConnStateChange(sc2, connectivity.TransientFailure)
|
||||
p2 := <-cc.newPickerCh
|
||||
// Expect two sc1's in the result, because balancer1 will be picked twice,
|
||||
// but there's only one sc in it.
|
||||
want = []balancer.SubConn{sc1, sc1, sc3, sc4}
|
||||
if err := isRoundRobin(want, func() balancer.SubConn {
|
||||
sc, _, _ := p2.Pick(context.Background(), balancer.PickOptions{})
|
||||
return sc
|
||||
}); err != nil {
|
||||
t.Fatalf("want %v, got %v", want, err)
|
||||
}
|
||||
|
||||
// Remove sc3's addresses.
|
||||
bg.handleResolvedAddrs(testBalancerIDs[1], testBackendAddrs[3:4])
|
||||
scToRemove := <-cc.removeSubConnCh
|
||||
if !reflect.DeepEqual(scToRemove, sc3) {
|
||||
t.Fatalf("RemoveSubConn, want %v, got %v", sc3, scToRemove)
|
||||
}
|
||||
bg.handleSubConnStateChange(scToRemove, connectivity.Shutdown)
|
||||
p3 := <-cc.newPickerCh
|
||||
want = []balancer.SubConn{sc1, sc4}
|
||||
if err := isRoundRobin(want, func() balancer.SubConn {
|
||||
sc, _, _ := p3.Pick(context.Background(), balancer.PickOptions{})
|
||||
return sc
|
||||
}); err != nil {
|
||||
t.Fatalf("want %v, got %v", want, err)
|
||||
}
|
||||
|
||||
// Turn sc1's connection down.
|
||||
bg.handleSubConnStateChange(sc1, connectivity.TransientFailure)
|
||||
p4 := <-cc.newPickerCh
|
||||
want = []balancer.SubConn{sc4}
|
||||
if err := isRoundRobin(want, func() balancer.SubConn {
|
||||
sc, _, _ := p4.Pick(context.Background(), balancer.PickOptions{})
|
||||
return sc
|
||||
}); err != nil {
|
||||
t.Fatalf("want %v, got %v", want, err)
|
||||
}
|
||||
|
||||
// Turn last connection to connecting.
|
||||
bg.handleSubConnStateChange(sc4, connectivity.Connecting)
|
||||
p5 := <-cc.newPickerCh
|
||||
for i := 0; i < 5; i++ {
|
||||
if _, _, err := p5.Pick(context.Background(), balancer.PickOptions{}); err != balancer.ErrNoSubConnAvailable {
|
||||
t.Fatalf("want pick error %v, got %v", balancer.ErrNoSubConnAvailable, err)
|
||||
}
|
||||
}
|
||||
|
||||
// Turn all connections down.
|
||||
bg.handleSubConnStateChange(sc4, connectivity.TransientFailure)
|
||||
p6 := <-cc.newPickerCh
|
||||
for i := 0; i < 5; i++ {
|
||||
if _, _, err := p6.Pick(context.Background(), balancer.PickOptions{}); err != balancer.ErrTransientFailure {
|
||||
t.Fatalf("want pick error %v, got %v", balancer.ErrTransientFailure, err)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// 2 balancers with different weights.
|
||||
func TestBalancerGroup_TwoRR_DifferentWeight_MoreBackends(t *testing.T) {
|
||||
cc := newTestClientConn(t)
|
||||
bg := newBalancerGroup(cc)
|
||||
|
||||
// Add two balancers to group and send two resolved addresses to both
|
||||
// balancers.
|
||||
bg.add(testBalancerIDs[0], 2, rrBuilder)
|
||||
bg.handleResolvedAddrs(testBalancerIDs[0], testBackendAddrs[0:2])
|
||||
sc1 := <-cc.newSubConnCh
|
||||
sc2 := <-cc.newSubConnCh
|
||||
|
||||
bg.add(testBalancerIDs[1], 1, rrBuilder)
|
||||
bg.handleResolvedAddrs(testBalancerIDs[1], testBackendAddrs[2:4])
|
||||
sc3 := <-cc.newSubConnCh
|
||||
sc4 := <-cc.newSubConnCh
|
||||
|
||||
// Send state changes for both subconns.
|
||||
bg.handleSubConnStateChange(sc1, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc1, connectivity.Ready)
|
||||
bg.handleSubConnStateChange(sc2, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc2, connectivity.Ready)
|
||||
bg.handleSubConnStateChange(sc3, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc3, connectivity.Ready)
|
||||
bg.handleSubConnStateChange(sc4, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc4, connectivity.Ready)
|
||||
|
||||
// Test roundrobin on the last picker.
|
||||
p1 := <-cc.newPickerCh
|
||||
want := []balancer.SubConn{sc1, sc1, sc2, sc2, sc3, sc4}
|
||||
if err := isRoundRobin(want, func() balancer.SubConn {
|
||||
sc, _, _ := p1.Pick(context.Background(), balancer.PickOptions{})
|
||||
return sc
|
||||
}); err != nil {
|
||||
t.Fatalf("want %v, got %v", want, err)
|
||||
}
|
||||
}
|
||||
|
||||
// totally 3 balancers, add/remove balancer.
|
||||
func TestBalancerGroup_ThreeRR_RemoveBalancer(t *testing.T) {
|
||||
cc := newTestClientConn(t)
|
||||
bg := newBalancerGroup(cc)
|
||||
|
||||
// Add three balancers to group and send one resolved address to both
|
||||
// balancers.
|
||||
bg.add(testBalancerIDs[0], 1, rrBuilder)
|
||||
bg.handleResolvedAddrs(testBalancerIDs[0], testBackendAddrs[0:1])
|
||||
sc1 := <-cc.newSubConnCh
|
||||
|
||||
bg.add(testBalancerIDs[1], 1, rrBuilder)
|
||||
bg.handleResolvedAddrs(testBalancerIDs[1], testBackendAddrs[1:2])
|
||||
sc2 := <-cc.newSubConnCh
|
||||
|
||||
bg.add(testBalancerIDs[2], 1, rrBuilder)
|
||||
bg.handleResolvedAddrs(testBalancerIDs[2], testBackendAddrs[1:2])
|
||||
sc3 := <-cc.newSubConnCh
|
||||
|
||||
// Send state changes for both subconns.
|
||||
bg.handleSubConnStateChange(sc1, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc1, connectivity.Ready)
|
||||
bg.handleSubConnStateChange(sc2, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc2, connectivity.Ready)
|
||||
bg.handleSubConnStateChange(sc3, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc3, connectivity.Ready)
|
||||
|
||||
p1 := <-cc.newPickerCh
|
||||
want := []balancer.SubConn{sc1, sc2, sc3}
|
||||
if err := isRoundRobin(want, func() balancer.SubConn {
|
||||
sc, _, _ := p1.Pick(context.Background(), balancer.PickOptions{})
|
||||
return sc
|
||||
}); err != nil {
|
||||
t.Fatalf("want %v, got %v", want, err)
|
||||
}
|
||||
|
||||
// Remove the second balancer, while the others two are ready.
|
||||
bg.remove(testBalancerIDs[1])
|
||||
scToRemove := <-cc.removeSubConnCh
|
||||
if !reflect.DeepEqual(scToRemove, sc2) {
|
||||
t.Fatalf("RemoveSubConn, want %v, got %v", sc2, scToRemove)
|
||||
}
|
||||
p2 := <-cc.newPickerCh
|
||||
want = []balancer.SubConn{sc1, sc3}
|
||||
if err := isRoundRobin(want, func() balancer.SubConn {
|
||||
sc, _, _ := p2.Pick(context.Background(), balancer.PickOptions{})
|
||||
return sc
|
||||
}); err != nil {
|
||||
t.Fatalf("want %v, got %v", want, err)
|
||||
}
|
||||
|
||||
// move balancer 3 into transient failure.
|
||||
bg.handleSubConnStateChange(sc3, connectivity.TransientFailure)
|
||||
// Remove the first balancer, while the third is transient failure.
|
||||
bg.remove(testBalancerIDs[0])
|
||||
scToRemove = <-cc.removeSubConnCh
|
||||
if !reflect.DeepEqual(scToRemove, sc1) {
|
||||
t.Fatalf("RemoveSubConn, want %v, got %v", sc1, scToRemove)
|
||||
}
|
||||
p3 := <-cc.newPickerCh
|
||||
for i := 0; i < 5; i++ {
|
||||
if _, _, err := p3.Pick(context.Background(), balancer.PickOptions{}); err != balancer.ErrTransientFailure {
|
||||
t.Fatalf("want pick error %v, got %v", balancer.ErrTransientFailure, err)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// 2 balancers, change balancer weight.
|
||||
func TestBalancerGroup_TwoRR_ChangeWeight_MoreBackends(t *testing.T) {
|
||||
cc := newTestClientConn(t)
|
||||
bg := newBalancerGroup(cc)
|
||||
|
||||
// Add two balancers to group and send two resolved addresses to both
|
||||
// balancers.
|
||||
bg.add(testBalancerIDs[0], 2, rrBuilder)
|
||||
bg.handleResolvedAddrs(testBalancerIDs[0], testBackendAddrs[0:2])
|
||||
sc1 := <-cc.newSubConnCh
|
||||
sc2 := <-cc.newSubConnCh
|
||||
|
||||
bg.add(testBalancerIDs[1], 1, rrBuilder)
|
||||
bg.handleResolvedAddrs(testBalancerIDs[1], testBackendAddrs[2:4])
|
||||
sc3 := <-cc.newSubConnCh
|
||||
sc4 := <-cc.newSubConnCh
|
||||
|
||||
// Send state changes for both subconns.
|
||||
bg.handleSubConnStateChange(sc1, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc1, connectivity.Ready)
|
||||
bg.handleSubConnStateChange(sc2, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc2, connectivity.Ready)
|
||||
bg.handleSubConnStateChange(sc3, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc3, connectivity.Ready)
|
||||
bg.handleSubConnStateChange(sc4, connectivity.Connecting)
|
||||
bg.handleSubConnStateChange(sc4, connectivity.Ready)
|
||||
|
||||
// Test roundrobin on the last picker.
|
||||
p1 := <-cc.newPickerCh
|
||||
want := []balancer.SubConn{sc1, sc1, sc2, sc2, sc3, sc4}
|
||||
if err := isRoundRobin(want, func() balancer.SubConn {
|
||||
sc, _, _ := p1.Pick(context.Background(), balancer.PickOptions{})
|
||||
return sc
|
||||
}); err != nil {
|
||||
t.Fatalf("want %v, got %v", want, err)
|
||||
}
|
||||
|
||||
bg.changeWeight(testBalancerIDs[0], 3)
|
||||
|
||||
// Test roundrobin with new weight.
|
||||
p2 := <-cc.newPickerCh
|
||||
want = []balancer.SubConn{sc1, sc1, sc1, sc2, sc2, sc2, sc3, sc4}
|
||||
if err := isRoundRobin(want, func() balancer.SubConn {
|
||||
sc, _, _ := p2.Pick(context.Background(), balancer.PickOptions{})
|
||||
return sc
|
||||
}); err != nil {
|
||||
t.Fatalf("want %v, got %v", want, err)
|
||||
}
|
||||
}
|
||||
298
balancer/xds/edsbalancer/test_util_test.go
Normal file
298
balancer/xds/edsbalancer/test_util_test.go
Normal file
@ -0,0 +1,298 @@
|
||||
/*
|
||||
* Copyright 2019 gRPC authors.
|
||||
*
|
||||
* Licensed 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 edsbalancer
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"testing"
|
||||
|
||||
"google.golang.org/grpc/balancer"
|
||||
"google.golang.org/grpc/connectivity"
|
||||
"google.golang.org/grpc/resolver"
|
||||
)
|
||||
|
||||
var (
|
||||
testSubConns = []*testSubConn{{id: "sc1"}, {id: "sc2"}, {id: "sc3"}, {id: "sc4"}}
|
||||
)
|
||||
|
||||
type testSubConn struct {
|
||||
id string
|
||||
}
|
||||
|
||||
func (tsc *testSubConn) UpdateAddresses([]resolver.Address) {
|
||||
panic("not implemented")
|
||||
}
|
||||
|
||||
func (tsc *testSubConn) Connect() {
|
||||
}
|
||||
|
||||
// Implement stringer to get human friendly error message.
|
||||
func (tsc *testSubConn) String() string {
|
||||
return tsc.id
|
||||
}
|
||||
|
||||
type testClientConn struct {
|
||||
t *testing.T // For logging only.
|
||||
|
||||
newSubConnAddrsCh chan []resolver.Address // The last 10 []Address to create subconn.
|
||||
newSubConnCh chan balancer.SubConn // The last 10 subconn created.
|
||||
removeSubConnCh chan balancer.SubConn // The last 10 subconn removed.
|
||||
|
||||
newPickerCh chan balancer.Picker // The last picker updated.
|
||||
newStateCh chan connectivity.State // The last state.
|
||||
|
||||
subConnIdx int
|
||||
}
|
||||
|
||||
func newTestClientConn(t *testing.T) *testClientConn {
|
||||
return &testClientConn{
|
||||
t: t,
|
||||
|
||||
newSubConnAddrsCh: make(chan []resolver.Address, 10),
|
||||
newSubConnCh: make(chan balancer.SubConn, 10),
|
||||
removeSubConnCh: make(chan balancer.SubConn, 10),
|
||||
|
||||
newPickerCh: make(chan balancer.Picker, 1),
|
||||
newStateCh: make(chan connectivity.State, 1),
|
||||
}
|
||||
}
|
||||
|
||||
func (tcc *testClientConn) NewSubConn(a []resolver.Address, o balancer.NewSubConnOptions) (balancer.SubConn, error) {
|
||||
sc := testSubConns[tcc.subConnIdx]
|
||||
tcc.subConnIdx++
|
||||
|
||||
tcc.t.Logf("testClientConn: NewSubConn(%v, %+v) => %p", a, o, sc)
|
||||
select {
|
||||
case tcc.newSubConnAddrsCh <- a:
|
||||
default:
|
||||
}
|
||||
|
||||
select {
|
||||
case tcc.newSubConnCh <- sc:
|
||||
default:
|
||||
}
|
||||
|
||||
return sc, nil
|
||||
}
|
||||
|
||||
func (tcc *testClientConn) RemoveSubConn(sc balancer.SubConn) {
|
||||
tcc.t.Logf("testClientCOnn: RemoveSubConn(%p)", sc)
|
||||
select {
|
||||
case tcc.removeSubConnCh <- sc:
|
||||
default:
|
||||
}
|
||||
}
|
||||
|
||||
func (tcc *testClientConn) UpdateBalancerState(s connectivity.State, p balancer.Picker) {
|
||||
tcc.t.Logf("testClientConn: UpdateBalancerState(%v, %p)", s, p)
|
||||
select {
|
||||
case <-tcc.newStateCh:
|
||||
default:
|
||||
}
|
||||
tcc.newStateCh <- s
|
||||
|
||||
select {
|
||||
case <-tcc.newPickerCh:
|
||||
default:
|
||||
}
|
||||
tcc.newPickerCh <- p
|
||||
}
|
||||
|
||||
func (tcc *testClientConn) ResolveNow(resolver.ResolveNowOption) {
|
||||
panic("not implemented")
|
||||
}
|
||||
|
||||
func (tcc *testClientConn) Target() string {
|
||||
panic("not implemented")
|
||||
}
|
||||
|
||||
// isRoundRobin checks whether f's return value is roundrobin of elements from
|
||||
// want. But it doesn't check for the order. Note that want can contain
|
||||
// duplicate items, which makes it weight-round-robin.
|
||||
//
|
||||
// Step 1. the return values of f should form a permutation of all elements in
|
||||
// want, but not necessary in the same order. E.g. if want is {a,a,b}, the check
|
||||
// fails if f returns:
|
||||
// - {a,a,a}: third a is returned before b
|
||||
// - {a,b,b}: second b is returned before the second a
|
||||
//
|
||||
// If error is found in this step, the returned error contains only the first
|
||||
// iteration until where it goes wrong.
|
||||
//
|
||||
// Step 2. the return values of f should be repetitions of the same permutation.
|
||||
// E.g. if want is {a,a,b}, the check failes if f returns:
|
||||
// - {a,b,a,b,a,a}: though it satisfies step 1, the second iteration is not
|
||||
// repeating the first iteration.
|
||||
//
|
||||
// If error is found in this step, the returned error contains the first
|
||||
// iteration + the second iteration until where it goes wrong.
|
||||
func isRoundRobin(want []balancer.SubConn, f func() balancer.SubConn) error {
|
||||
wantSet := make(map[balancer.SubConn]int) // SubConn -> count, for weighted RR.
|
||||
for _, sc := range want {
|
||||
wantSet[sc]++
|
||||
}
|
||||
|
||||
// The first iteration: makes sure f's return values form a permutation of
|
||||
// elements in want.
|
||||
//
|
||||
// Also keep the returns values in a slice, so we can compare the order in
|
||||
// the second iteration.
|
||||
gotSliceFirstIteration := make([]balancer.SubConn, 0, len(want))
|
||||
for range want {
|
||||
got := f()
|
||||
gotSliceFirstIteration = append(gotSliceFirstIteration, got)
|
||||
wantSet[got]--
|
||||
if wantSet[got] < 0 {
|
||||
return fmt.Errorf("non-roundrobin want: %v, result: %v", want, gotSliceFirstIteration)
|
||||
}
|
||||
}
|
||||
|
||||
// The second iteration should repeat the first iteration.
|
||||
var gotSliceSecondIteration []balancer.SubConn
|
||||
for i := 0; i < 2; i++ {
|
||||
for _, w := range gotSliceFirstIteration {
|
||||
g := f()
|
||||
gotSliceSecondIteration = append(gotSliceSecondIteration, g)
|
||||
if w != g {
|
||||
return fmt.Errorf("non-roundrobin, first iter: %v, second iter: %v", gotSliceFirstIteration, gotSliceSecondIteration)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// testClosure is a test util for TestIsRoundRobin.
|
||||
type testClosure struct {
|
||||
r []balancer.SubConn
|
||||
i int
|
||||
}
|
||||
|
||||
func (tc *testClosure) next() balancer.SubConn {
|
||||
ret := tc.r[tc.i]
|
||||
tc.i = (tc.i + 1) % len(tc.r)
|
||||
return ret
|
||||
}
|
||||
|
||||
func TestIsRoundRobin(t *testing.T) {
|
||||
var (
|
||||
sc1 = testSubConns[0]
|
||||
sc2 = testSubConns[1]
|
||||
sc3 = testSubConns[2]
|
||||
)
|
||||
|
||||
testCases := []struct {
|
||||
desc string
|
||||
want []balancer.SubConn
|
||||
got []balancer.SubConn
|
||||
pass bool
|
||||
}{
|
||||
{
|
||||
desc: "0 element",
|
||||
want: []balancer.SubConn{},
|
||||
got: []balancer.SubConn{},
|
||||
pass: true,
|
||||
},
|
||||
{
|
||||
desc: "1 element RR",
|
||||
want: []balancer.SubConn{sc1},
|
||||
got: []balancer.SubConn{sc1, sc1, sc1, sc1},
|
||||
pass: true,
|
||||
},
|
||||
{
|
||||
desc: "1 element not RR",
|
||||
want: []balancer.SubConn{sc1},
|
||||
got: []balancer.SubConn{sc1, sc2, sc1},
|
||||
pass: false,
|
||||
},
|
||||
{
|
||||
desc: "2 elements RR",
|
||||
want: []balancer.SubConn{sc1, sc2},
|
||||
got: []balancer.SubConn{sc1, sc2, sc1, sc2, sc1, sc2},
|
||||
pass: true,
|
||||
},
|
||||
{
|
||||
desc: "2 elements RR different order from want",
|
||||
want: []balancer.SubConn{sc2, sc1},
|
||||
got: []balancer.SubConn{sc1, sc2, sc1, sc2, sc1, sc2},
|
||||
pass: true,
|
||||
},
|
||||
{
|
||||
desc: "2 elements RR not RR, mistake in first iter",
|
||||
want: []balancer.SubConn{sc1, sc2},
|
||||
got: []balancer.SubConn{sc1, sc1, sc1, sc2, sc1, sc2},
|
||||
pass: false,
|
||||
},
|
||||
{
|
||||
desc: "2 elements RR not RR, mistake in second iter",
|
||||
want: []balancer.SubConn{sc1, sc2},
|
||||
got: []balancer.SubConn{sc1, sc2, sc1, sc1, sc1, sc2},
|
||||
pass: false,
|
||||
},
|
||||
{
|
||||
desc: "2 elements weighted RR",
|
||||
want: []balancer.SubConn{sc1, sc1, sc2},
|
||||
got: []balancer.SubConn{sc1, sc1, sc2, sc1, sc1, sc2},
|
||||
pass: true,
|
||||
},
|
||||
{
|
||||
desc: "2 elements weighted RR different order",
|
||||
want: []balancer.SubConn{sc1, sc1, sc2},
|
||||
got: []balancer.SubConn{sc1, sc2, sc1, sc1, sc2, sc1},
|
||||
pass: true,
|
||||
},
|
||||
|
||||
{
|
||||
desc: "3 elements RR",
|
||||
want: []balancer.SubConn{sc1, sc2, sc3},
|
||||
got: []balancer.SubConn{sc1, sc2, sc3, sc1, sc2, sc3, sc1, sc2, sc3},
|
||||
pass: true,
|
||||
},
|
||||
{
|
||||
desc: "3 elements RR different order",
|
||||
want: []balancer.SubConn{sc1, sc2, sc3},
|
||||
got: []balancer.SubConn{sc3, sc2, sc1, sc3, sc2, sc1},
|
||||
pass: true,
|
||||
},
|
||||
{
|
||||
desc: "3 elements weighted RR",
|
||||
want: []balancer.SubConn{sc1, sc1, sc1, sc2, sc2, sc3},
|
||||
got: []balancer.SubConn{sc1, sc2, sc3, sc1, sc2, sc1, sc1, sc2, sc3, sc1, sc2, sc1},
|
||||
pass: true,
|
||||
},
|
||||
{
|
||||
desc: "3 elements weighted RR not RR, mistake in first iter",
|
||||
want: []balancer.SubConn{sc1, sc1, sc1, sc2, sc2, sc3},
|
||||
got: []balancer.SubConn{sc1, sc2, sc1, sc1, sc2, sc1, sc1, sc2, sc3, sc1, sc2, sc1},
|
||||
pass: false,
|
||||
},
|
||||
{
|
||||
desc: "3 elements weighted RR not RR, mistake in second iter",
|
||||
want: []balancer.SubConn{sc1, sc1, sc1, sc2, sc2, sc3},
|
||||
got: []balancer.SubConn{sc1, sc2, sc3, sc1, sc2, sc1, sc1, sc1, sc3, sc1, sc2, sc1},
|
||||
pass: false,
|
||||
},
|
||||
}
|
||||
for _, tC := range testCases {
|
||||
t.Run(tC.desc, func(t *testing.T) {
|
||||
err := isRoundRobin(tC.want, (&testClosure{r: tC.got}).next)
|
||||
if err == nil != tC.pass {
|
||||
t.Errorf("want pass %v, want %v, got err %v", tC.pass, tC.want, err)
|
||||
}
|
||||
})
|
||||
}
|
||||
}
|
||||
18
balancer/xds/xds.go
Normal file
18
balancer/xds/xds.go
Normal file
@ -0,0 +1,18 @@
|
||||
/*
|
||||
* Copyright 2019 gRPC authors.
|
||||
*
|
||||
* Licensed 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 xds implements xds balancer.
|
||||
package xds // import "google.golang.org/grpc/balancer/xds"
|
||||
Reference in New Issue
Block a user