mirror of
https://github.com/etcd-io/etcd.git
synced 2024-09-27 06:25:44 +00:00
b67303c6a2
This change introduces joint quorums by changing the Node and RawNode API to accept pb.ConfChangeV2 (on top of pb.ConfChange). pb.ConfChange continues to work as today: it allows carrying out a single configuration change. A pb.ConfChange proposal gets added to the Raft log as such and is thus also observed by the app during Ready handling, and fed back to ApplyConfChange. ConfChangeV2 allows joint configuration changes but will continue to carry out configuration changes in "one phase" (i.e. without ever entering a joint config) when this is possible.
81 lines
2.9 KiB
Go
81 lines
2.9 KiB
Go
// Copyright 2015 The etcd 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 raft
|
|
|
|
import (
|
|
"errors"
|
|
|
|
pb "go.etcd.io/etcd/raft/raftpb"
|
|
)
|
|
|
|
// Bootstrap initializes the RawNode for first use by appending configuration
|
|
// changes for the supplied peers. This method returns an error if the Storage
|
|
// is nonempty.
|
|
//
|
|
// It is recommended that instead of calling this method, applications bootstrap
|
|
// their state manually by setting up a Storage that has a first index > 1 and
|
|
// which stores the desired ConfState as its InitialState.
|
|
func (rn *RawNode) Bootstrap(peers []Peer) error {
|
|
if len(peers) == 0 {
|
|
return errors.New("must provide at least one peer to Bootstrap")
|
|
}
|
|
lastIndex, err := rn.raft.raftLog.storage.LastIndex()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if lastIndex != 0 {
|
|
return errors.New("can't bootstrap a nonempty Storage")
|
|
}
|
|
|
|
// We've faked out initial entries above, but nothing has been
|
|
// persisted. Start with an empty HardState (thus the first Ready will
|
|
// emit a HardState update for the app to persist).
|
|
rn.prevHardSt = emptyState
|
|
|
|
// TODO(tbg): remove StartNode and give the application the right tools to
|
|
// bootstrap the initial membership in a cleaner way.
|
|
rn.raft.becomeFollower(1, None)
|
|
ents := make([]pb.Entry, len(peers))
|
|
for i, peer := range peers {
|
|
cc := pb.ConfChange{Type: pb.ConfChangeAddNode, NodeID: peer.ID, Context: peer.Context}
|
|
data, err := cc.Marshal()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
ents[i] = pb.Entry{Type: pb.EntryConfChange, Term: 1, Index: uint64(i + 1), Data: data}
|
|
}
|
|
rn.raft.raftLog.append(ents...)
|
|
|
|
// Now apply them, mainly so that the application can call Campaign
|
|
// immediately after StartNode in tests. Note that these nodes will
|
|
// be added to raft twice: here and when the application's Ready
|
|
// loop calls ApplyConfChange. The calls to addNode must come after
|
|
// all calls to raftLog.append so progress.next is set after these
|
|
// bootstrapping entries (it is an error if we try to append these
|
|
// entries since they have already been committed).
|
|
// We do not set raftLog.applied so the application will be able
|
|
// to observe all conf changes via Ready.CommittedEntries.
|
|
//
|
|
// TODO(bdarnell): These entries are still unstable; do we need to preserve
|
|
// the invariant that committed < unstable?
|
|
rn.raft.raftLog.committed = uint64(len(ents))
|
|
for _, peer := range peers {
|
|
rn.raft.applyConfChange(pb.ConfChange{NodeID: peer.ID, Type: pb.ConfChangeAddNode}.AsV2())
|
|
}
|
|
return nil
|
|
}
|