[VOL-2538] Logging - Implement dynamic log levels in ofagent
Change-Id: I9582230d9d3c34ea84339fddf2b2f3b3d2804808
diff --git a/vendor/go.etcd.io/etcd/raft/tracker/progress.go b/vendor/go.etcd.io/etcd/raft/tracker/progress.go
new file mode 100644
index 0000000..62c81f4
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/raft/tracker/progress.go
@@ -0,0 +1,259 @@
+// Copyright 2019 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 tracker
+
+import (
+ "fmt"
+ "sort"
+ "strings"
+)
+
+// Progress represents a follower’s progress in the view of the leader. Leader
+// maintains progresses of all followers, and sends entries to the follower
+// based on its progress.
+//
+// NB(tbg): Progress is basically a state machine whose transitions are mostly
+// strewn around `*raft.raft`. Additionally, some fields are only used when in a
+// certain State. All of this isn't ideal.
+type Progress struct {
+ Match, Next uint64
+ // State defines how the leader should interact with the follower.
+ //
+ // When in StateProbe, leader sends at most one replication message
+ // per heartbeat interval. It also probes actual progress of the follower.
+ //
+ // When in StateReplicate, leader optimistically increases next
+ // to the latest entry sent after sending replication message. This is
+ // an optimized state for fast replicating log entries to the follower.
+ //
+ // When in StateSnapshot, leader should have sent out snapshot
+ // before and stops sending any replication message.
+ State StateType
+
+ // PendingSnapshot is used in StateSnapshot.
+ // If there is a pending snapshot, the pendingSnapshot will be set to the
+ // index of the snapshot. If pendingSnapshot is set, the replication process of
+ // this Progress will be paused. raft will not resend snapshot until the pending one
+ // is reported to be failed.
+ PendingSnapshot uint64
+
+ // RecentActive is true if the progress is recently active. Receiving any messages
+ // from the corresponding follower indicates the progress is active.
+ // RecentActive can be reset to false after an election timeout.
+ //
+ // TODO(tbg): the leader should always have this set to true.
+ RecentActive bool
+
+ // ProbeSent is used while this follower is in StateProbe. When ProbeSent is
+ // true, raft should pause sending replication message to this peer until
+ // ProbeSent is reset. See ProbeAcked() and IsPaused().
+ ProbeSent bool
+
+ // Inflights is a sliding window for the inflight messages.
+ // Each inflight message contains one or more log entries.
+ // The max number of entries per message is defined in raft config as MaxSizePerMsg.
+ // Thus inflight effectively limits both the number of inflight messages
+ // and the bandwidth each Progress can use.
+ // When inflights is Full, no more message should be sent.
+ // When a leader sends out a message, the index of the last
+ // entry should be added to inflights. The index MUST be added
+ // into inflights in order.
+ // When a leader receives a reply, the previous inflights should
+ // be freed by calling inflights.FreeLE with the index of the last
+ // received entry.
+ Inflights *Inflights
+
+ // IsLearner is true if this progress is tracked for a learner.
+ IsLearner bool
+}
+
+// ResetState moves the Progress into the specified State, resetting ProbeSent,
+// PendingSnapshot, and Inflights.
+func (pr *Progress) ResetState(state StateType) {
+ pr.ProbeSent = false
+ pr.PendingSnapshot = 0
+ pr.State = state
+ pr.Inflights.reset()
+}
+
+func max(a, b uint64) uint64 {
+ if a > b {
+ return a
+ }
+ return b
+}
+
+func min(a, b uint64) uint64 {
+ if a > b {
+ return b
+ }
+ return a
+}
+
+// ProbeAcked is called when this peer has accepted an append. It resets
+// ProbeSent to signal that additional append messages should be sent without
+// further delay.
+func (pr *Progress) ProbeAcked() {
+ pr.ProbeSent = false
+}
+
+// BecomeProbe transitions into StateProbe. Next is reset to Match+1 or,
+// optionally and if larger, the index of the pending snapshot.
+func (pr *Progress) BecomeProbe() {
+ // If the original state is StateSnapshot, progress knows that
+ // the pending snapshot has been sent to this peer successfully, then
+ // probes from pendingSnapshot + 1.
+ if pr.State == StateSnapshot {
+ pendingSnapshot := pr.PendingSnapshot
+ pr.ResetState(StateProbe)
+ pr.Next = max(pr.Match+1, pendingSnapshot+1)
+ } else {
+ pr.ResetState(StateProbe)
+ pr.Next = pr.Match + 1
+ }
+}
+
+// BecomeReplicate transitions into StateReplicate, resetting Next to Match+1.
+func (pr *Progress) BecomeReplicate() {
+ pr.ResetState(StateReplicate)
+ pr.Next = pr.Match + 1
+}
+
+// BecomeSnapshot moves the Progress to StateSnapshot with the specified pending
+// snapshot index.
+func (pr *Progress) BecomeSnapshot(snapshoti uint64) {
+ pr.ResetState(StateSnapshot)
+ pr.PendingSnapshot = snapshoti
+}
+
+// MaybeUpdate is called when an MsgAppResp arrives from the follower, with the
+// index acked by it. The method returns false if the given n index comes from
+// an outdated message. Otherwise it updates the progress and returns true.
+func (pr *Progress) MaybeUpdate(n uint64) bool {
+ var updated bool
+ if pr.Match < n {
+ pr.Match = n
+ updated = true
+ pr.ProbeAcked()
+ }
+ if pr.Next < n+1 {
+ pr.Next = n + 1
+ }
+ return updated
+}
+
+// OptimisticUpdate signals that appends all the way up to and including index n
+// are in-flight. As a result, Next is increased to n+1.
+func (pr *Progress) OptimisticUpdate(n uint64) { pr.Next = n + 1 }
+
+// MaybeDecrTo adjusts the Progress to the receipt of a MsgApp rejection. The
+// arguments are the index the follower rejected to append to its log, and its
+// last index.
+//
+// Rejections can happen spuriously as messages are sent out of order or
+// duplicated. In such cases, the rejection pertains to an index that the
+// Progress already knows were previously acknowledged, and false is returned
+// without changing the Progress.
+//
+// If the rejection is genuine, Next is lowered sensibly, and the Progress is
+// cleared for sending log entries.
+func (pr *Progress) MaybeDecrTo(rejected, last uint64) bool {
+ if pr.State == StateReplicate {
+ // The rejection must be stale if the progress has matched and "rejected"
+ // is smaller than "match".
+ if rejected <= pr.Match {
+ return false
+ }
+ // Directly decrease next to match + 1.
+ //
+ // TODO(tbg): why not use last if it's larger?
+ pr.Next = pr.Match + 1
+ return true
+ }
+
+ // The rejection must be stale if "rejected" does not match next - 1. This
+ // is because non-replicating followers are probed one entry at a time.
+ if pr.Next-1 != rejected {
+ return false
+ }
+
+ if pr.Next = min(rejected, last+1); pr.Next < 1 {
+ pr.Next = 1
+ }
+ pr.ProbeSent = false
+ return true
+}
+
+// IsPaused returns whether sending log entries to this node has been throttled.
+// This is done when a node has rejected recent MsgApps, is currently waiting
+// for a snapshot, or has reached the MaxInflightMsgs limit. In normal
+// operation, this is false. A throttled node will be contacted less frequently
+// until it has reached a state in which it's able to accept a steady stream of
+// log entries again.
+func (pr *Progress) IsPaused() bool {
+ switch pr.State {
+ case StateProbe:
+ return pr.ProbeSent
+ case StateReplicate:
+ return pr.Inflights.Full()
+ case StateSnapshot:
+ return true
+ default:
+ panic("unexpected state")
+ }
+}
+
+func (pr *Progress) String() string {
+ var buf strings.Builder
+ fmt.Fprintf(&buf, "%s match=%d next=%d", pr.State, pr.Match, pr.Next)
+ if pr.IsLearner {
+ fmt.Fprint(&buf, " learner")
+ }
+ if pr.IsPaused() {
+ fmt.Fprint(&buf, " paused")
+ }
+ if pr.PendingSnapshot > 0 {
+ fmt.Fprintf(&buf, " pendingSnap=%d", pr.PendingSnapshot)
+ }
+ if !pr.RecentActive {
+ fmt.Fprintf(&buf, " inactive")
+ }
+ if n := pr.Inflights.Count(); n > 0 {
+ fmt.Fprintf(&buf, " inflight=%d", n)
+ if pr.Inflights.Full() {
+ fmt.Fprint(&buf, "[full]")
+ }
+ }
+ return buf.String()
+}
+
+// ProgressMap is a map of *Progress.
+type ProgressMap map[uint64]*Progress
+
+// String prints the ProgressMap in sorted key order, one Progress per line.
+func (m ProgressMap) String() string {
+ ids := make([]uint64, 0, len(m))
+ for k := range m {
+ ids = append(ids, k)
+ }
+ sort.Slice(ids, func(i, j int) bool {
+ return ids[i] < ids[j]
+ })
+ var buf strings.Builder
+ for _, id := range ids {
+ fmt.Fprintf(&buf, "%d: %s\n", id, m[id])
+ }
+ return buf.String()
+}