43 lines
1.5 KiB
Go
43 lines
1.5 KiB
Go
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// Copyright 2019 The etcd 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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package tracker
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// StateType is the state of a tracked follower.
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type StateType uint64
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const (
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// StateProbe indicates a follower whose last index isn't known. Such a
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// follower is "probed" (i.e. an append sent periodically) to narrow down
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// its last index. In the ideal (and common) case, only one round of probing
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// is necessary as the follower will react with a hint. Followers that are
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// probed over extended periods of time are often offline.
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StateProbe StateType = iota
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// StateReplicate is the state steady in which a follower eagerly receives
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// log entries to append to its log.
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StateReplicate
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// StateSnapshot indicates a follower that needs log entries not available
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// from the leader's Raft log. Such a follower needs a full snapshot to
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// return to StateReplicate.
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StateSnapshot
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)
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var prstmap = [...]string{
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"StateProbe",
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"StateReplicate",
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"StateSnapshot",
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}
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func (st StateType) String() string { return prstmap[uint64(st)] }
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