forked from hashicorp/nomad
/
fsm.go
586 lines (506 loc) · 14.5 KB
/
fsm.go
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package nomad
import (
"fmt"
"io"
"log"
"time"
"github.com/armon/go-metrics"
"github.com/hashicorp/go-msgpack/codec"
"github.com/hashicorp/nomad/nomad/state"
"github.com/hashicorp/nomad/nomad/structs"
"github.com/hashicorp/raft"
)
const (
// timeTableGranularity is the granularity of index to time tracking
timeTableGranularity = 5 * time.Minute
// timeTableLimit is the maximum limit of our tracking
timeTableLimit = 72 * time.Hour
)
// SnapshotType is prefixed to a record in the FSM snapshot
// so that we can determine the type for restore
type SnapshotType byte
const (
NodeSnapshot SnapshotType = iota
JobSnapshot
IndexSnapshot
EvalSnapshot
AllocSnapshot
TimeTableSnapshot
)
// nomadFSM implements a finite state machine that is used
// along with Raft to provide strong consistency. We implement
// this outside the Server to avoid exposing this outside the package.
type nomadFSM struct {
evalBroker *EvalBroker
logOutput io.Writer
logger *log.Logger
state *state.StateStore
timetable *TimeTable
}
// nomadSnapshot is used to provide a snapshot of the current
// state in a way that can be accessed concurrently with operations
// that may modify the live state.
type nomadSnapshot struct {
snap *state.StateSnapshot
timetable *TimeTable
}
// snapshotHeader is the first entry in our snapshot
type snapshotHeader struct {
}
// NewFSMPath is used to construct a new FSM with a blank state
func NewFSM(evalBroker *EvalBroker, logOutput io.Writer) (*nomadFSM, error) {
// Create a state store
state, err := state.NewStateStore(logOutput)
if err != nil {
return nil, err
}
fsm := &nomadFSM{
evalBroker: evalBroker,
logOutput: logOutput,
logger: log.New(logOutput, "", log.LstdFlags),
state: state,
timetable: NewTimeTable(timeTableGranularity, timeTableLimit),
}
return fsm, nil
}
// Close is used to cleanup resources associated with the FSM
func (n *nomadFSM) Close() error {
return nil
}
// State is used to return a handle to the current state
func (n *nomadFSM) State() *state.StateStore {
return n.state
}
// TimeTable returns the time table of transactions
func (n *nomadFSM) TimeTable() *TimeTable {
return n.timetable
}
func (n *nomadFSM) Apply(log *raft.Log) interface{} {
buf := log.Data
msgType := structs.MessageType(buf[0])
// Witness this write
n.timetable.Witness(log.Index, time.Now().UTC())
// Check if this message type should be ignored when unknown. This is
// used so that new commands can be added with developer control if older
// versions can safely ignore the command, or if they should crash.
ignoreUnknown := false
if msgType&structs.IgnoreUnknownTypeFlag == structs.IgnoreUnknownTypeFlag {
msgType &= ^structs.IgnoreUnknownTypeFlag
ignoreUnknown = true
}
switch msgType {
case structs.NodeRegisterRequestType:
return n.applyUpsertNode(buf[1:], log.Index)
case structs.NodeDeregisterRequestType:
return n.applyDeregisterNode(buf[1:], log.Index)
case structs.NodeUpdateStatusRequestType:
return n.applyStatusUpdate(buf[1:], log.Index)
case structs.NodeUpdateDrainRequestType:
return n.applyDrainUpdate(buf[1:], log.Index)
case structs.JobRegisterRequestType:
return n.applyUpsertJob(buf[1:], log.Index)
case structs.JobDeregisterRequestType:
return n.applyDeregisterJob(buf[1:], log.Index)
case structs.EvalUpdateRequestType:
return n.applyUpdateEval(buf[1:], log.Index)
case structs.EvalDeleteRequestType:
return n.applyDeleteEval(buf[1:], log.Index)
case structs.AllocUpdateRequestType:
return n.applyAllocUpdate(buf[1:], log.Index)
case structs.AllocClientUpdateRequestType:
return n.applyAllocClientUpdate(buf[1:], log.Index)
default:
if ignoreUnknown {
n.logger.Printf("[WARN] nomad.fsm: ignoring unknown message type (%d), upgrade to newer version", msgType)
return nil
} else {
panic(fmt.Errorf("failed to apply request: %#v", buf))
}
}
}
func (n *nomadFSM) applyUpsertNode(buf []byte, index uint64) interface{} {
defer metrics.MeasureSince([]string{"nomad", "fsm", "register_node"}, time.Now())
var req structs.NodeRegisterRequest
if err := structs.Decode(buf, &req); err != nil {
panic(fmt.Errorf("failed to decode request: %v", err))
}
if err := n.state.UpsertNode(index, req.Node); err != nil {
n.logger.Printf("[ERR] nomad.fsm: UpsertNode failed: %v", err)
return err
}
return nil
}
func (n *nomadFSM) applyDeregisterNode(buf []byte, index uint64) interface{} {
defer metrics.MeasureSince([]string{"nomad", "fsm", "deregister_node"}, time.Now())
var req structs.NodeDeregisterRequest
if err := structs.Decode(buf, &req); err != nil {
panic(fmt.Errorf("failed to decode request: %v", err))
}
if err := n.state.DeleteNode(index, req.NodeID); err != nil {
n.logger.Printf("[ERR] nomad.fsm: DeleteNode failed: %v", err)
return err
}
return nil
}
func (n *nomadFSM) applyStatusUpdate(buf []byte, index uint64) interface{} {
defer metrics.MeasureSince([]string{"nomad", "fsm", "node_status_update"}, time.Now())
var req structs.NodeUpdateStatusRequest
if err := structs.Decode(buf, &req); err != nil {
panic(fmt.Errorf("failed to decode request: %v", err))
}
if err := n.state.UpdateNodeStatus(index, req.NodeID, req.Status); err != nil {
n.logger.Printf("[ERR] nomad.fsm: UpdateNodeStatus failed: %v", err)
return err
}
return nil
}
func (n *nomadFSM) applyDrainUpdate(buf []byte, index uint64) interface{} {
defer metrics.MeasureSince([]string{"nomad", "fsm", "node_drain_update"}, time.Now())
var req structs.NodeUpdateDrainRequest
if err := structs.Decode(buf, &req); err != nil {
panic(fmt.Errorf("failed to decode request: %v", err))
}
if err := n.state.UpdateNodeDrain(index, req.NodeID, req.Drain); err != nil {
n.logger.Printf("[ERR] nomad.fsm: UpdateNodeDrain failed: %v", err)
return err
}
return nil
}
func (n *nomadFSM) applyUpsertJob(buf []byte, index uint64) interface{} {
defer metrics.MeasureSince([]string{"nomad", "fsm", "register_job"}, time.Now())
var req structs.JobRegisterRequest
if err := structs.Decode(buf, &req); err != nil {
panic(fmt.Errorf("failed to decode request: %v", err))
}
if err := n.state.UpsertJob(index, req.Job); err != nil {
n.logger.Printf("[ERR] nomad.fsm: UpsertJob failed: %v", err)
return err
}
return nil
}
func (n *nomadFSM) applyDeregisterJob(buf []byte, index uint64) interface{} {
defer metrics.MeasureSince([]string{"nomad", "fsm", "deregister_job"}, time.Now())
var req structs.JobDeregisterRequest
if err := structs.Decode(buf, &req); err != nil {
panic(fmt.Errorf("failed to decode request: %v", err))
}
if err := n.state.DeleteJob(index, req.JobID); err != nil {
n.logger.Printf("[ERR] nomad.fsm: DeleteJob failed: %v", err)
return err
}
return nil
}
func (n *nomadFSM) applyUpdateEval(buf []byte, index uint64) interface{} {
defer metrics.MeasureSince([]string{"nomad", "fsm", "update_eval"}, time.Now())
var req structs.EvalUpdateRequest
if err := structs.Decode(buf, &req); err != nil {
panic(fmt.Errorf("failed to decode request: %v", err))
}
if err := n.state.UpsertEvals(index, req.Evals); err != nil {
n.logger.Printf("[ERR] nomad.fsm: UpsertEvals failed: %v", err)
return err
}
for _, eval := range req.Evals {
if eval.ShouldEnqueue() {
if err := n.evalBroker.Enqueue(eval); err != nil {
n.logger.Printf("[ERR] nomad.fsm: failed to enqueue evaluation %s: %v", eval.ID, err)
return err
}
}
}
return nil
}
func (n *nomadFSM) applyDeleteEval(buf []byte, index uint64) interface{} {
defer metrics.MeasureSince([]string{"nomad", "fsm", "delete_eval"}, time.Now())
var req structs.EvalDeleteRequest
if err := structs.Decode(buf, &req); err != nil {
panic(fmt.Errorf("failed to decode request: %v", err))
}
if err := n.state.DeleteEval(index, req.Evals, req.Allocs); err != nil {
n.logger.Printf("[ERR] nomad.fsm: DeleteEval failed: %v", err)
return err
}
return nil
}
func (n *nomadFSM) applyAllocUpdate(buf []byte, index uint64) interface{} {
defer metrics.MeasureSince([]string{"nomad", "fsm", "alloc_update"}, time.Now())
var req structs.AllocUpdateRequest
if err := structs.Decode(buf, &req); err != nil {
panic(fmt.Errorf("failed to decode request: %v", err))
}
if err := n.state.UpsertAllocs(index, req.Alloc); err != nil {
n.logger.Printf("[ERR] nomad.fsm: UpsertAllocs failed: %v", err)
return err
}
return nil
}
func (n *nomadFSM) applyAllocClientUpdate(buf []byte, index uint64) interface{} {
defer metrics.MeasureSince([]string{"nomad", "fsm", "alloc_client_update"}, time.Now())
var req structs.AllocUpdateRequest
if err := structs.Decode(buf, &req); err != nil {
panic(fmt.Errorf("failed to decode request: %v", err))
}
if len(req.Alloc) == 0 {
return nil
}
if err := n.state.UpdateAllocFromClient(index, req.Alloc[0]); err != nil {
n.logger.Printf("[ERR] nomad.fsm: UpdateAllocFromClient failed: %v", err)
return err
}
return nil
}
func (n *nomadFSM) Snapshot() (raft.FSMSnapshot, error) {
// Create a new snapshot
snap, err := n.state.Snapshot()
if err != nil {
return nil, err
}
ns := &nomadSnapshot{
snap: snap,
timetable: n.timetable,
}
return ns, nil
}
func (n *nomadFSM) Restore(old io.ReadCloser) error {
defer old.Close()
// Create a new state store
newState, err := state.NewStateStore(n.logOutput)
if err != nil {
return err
}
n.state = newState
// Start the state restore
restore, err := newState.Restore()
if err != nil {
return err
}
defer restore.Abort()
// Create a decoder
dec := codec.NewDecoder(old, structs.MsgpackHandle)
// Read in the header
var header snapshotHeader
if err := dec.Decode(&header); err != nil {
return err
}
// Populate the new state
msgType := make([]byte, 1)
for {
// Read the message type
_, err := old.Read(msgType)
if err == io.EOF {
break
} else if err != nil {
return err
}
// Decode
switch SnapshotType(msgType[0]) {
case TimeTableSnapshot:
if err := n.timetable.Deserialize(dec); err != nil {
return fmt.Errorf("time table deserialize failed: %v", err)
}
case NodeSnapshot:
node := new(structs.Node)
if err := dec.Decode(node); err != nil {
return err
}
if err := restore.NodeRestore(node); err != nil {
return err
}
case JobSnapshot:
job := new(structs.Job)
if err := dec.Decode(job); err != nil {
return err
}
if err := restore.JobRestore(job); err != nil {
return err
}
case EvalSnapshot:
eval := new(structs.Evaluation)
if err := dec.Decode(eval); err != nil {
return err
}
if err := restore.EvalRestore(eval); err != nil {
return err
}
case AllocSnapshot:
alloc := new(structs.Allocation)
if err := dec.Decode(alloc); err != nil {
return err
}
if err := restore.AllocRestore(alloc); err != nil {
return err
}
case IndexSnapshot:
idx := new(state.IndexEntry)
if err := dec.Decode(idx); err != nil {
return err
}
if err := restore.IndexRestore(idx); err != nil {
return err
}
default:
return fmt.Errorf("Unrecognized snapshot type: %v", msgType)
}
}
// Commit the state restore
restore.Commit()
return nil
}
func (s *nomadSnapshot) Persist(sink raft.SnapshotSink) error {
defer metrics.MeasureSince([]string{"nomad", "fsm", "persist"}, time.Now())
// Register the nodes
encoder := codec.NewEncoder(sink, structs.MsgpackHandle)
// Write the header
header := snapshotHeader{}
if err := encoder.Encode(&header); err != nil {
sink.Cancel()
return err
}
// Write the time table
sink.Write([]byte{byte(TimeTableSnapshot)})
if err := s.timetable.Serialize(encoder); err != nil {
sink.Cancel()
return err
}
// Write all the data out
if err := s.persistIndexes(sink, encoder); err != nil {
sink.Cancel()
return err
}
if err := s.persistNodes(sink, encoder); err != nil {
sink.Cancel()
return err
}
if err := s.persistJobs(sink, encoder); err != nil {
sink.Cancel()
return err
}
if err := s.persistEvals(sink, encoder); err != nil {
sink.Cancel()
return err
}
if err := s.persistAllocs(sink, encoder); err != nil {
sink.Cancel()
return err
}
return nil
}
func (s *nomadSnapshot) persistIndexes(sink raft.SnapshotSink,
encoder *codec.Encoder) error {
// Get all the indexes
iter, err := s.snap.Indexes()
if err != nil {
return err
}
for {
// Get the next item
raw := iter.Next()
if raw == nil {
break
}
// Prepare the request struct
idx := raw.(*state.IndexEntry)
// Write out a node registration
sink.Write([]byte{byte(IndexSnapshot)})
if err := encoder.Encode(idx); err != nil {
return err
}
}
return nil
}
func (s *nomadSnapshot) persistNodes(sink raft.SnapshotSink,
encoder *codec.Encoder) error {
// Get all the nodes
nodes, err := s.snap.Nodes()
if err != nil {
return err
}
for {
// Get the next item
raw := nodes.Next()
if raw == nil {
break
}
// Prepare the request struct
node := raw.(*structs.Node)
// Write out a node registration
sink.Write([]byte{byte(NodeSnapshot)})
if err := encoder.Encode(node); err != nil {
return err
}
}
return nil
}
func (s *nomadSnapshot) persistJobs(sink raft.SnapshotSink,
encoder *codec.Encoder) error {
// Get all the jobs
jobs, err := s.snap.Jobs()
if err != nil {
return err
}
for {
// Get the next item
raw := jobs.Next()
if raw == nil {
break
}
// Prepare the request struct
job := raw.(*structs.Job)
// Write out a job registration
sink.Write([]byte{byte(JobSnapshot)})
if err := encoder.Encode(job); err != nil {
return err
}
}
return nil
}
func (s *nomadSnapshot) persistEvals(sink raft.SnapshotSink,
encoder *codec.Encoder) error {
// Get all the evaluations
evals, err := s.snap.Evals()
if err != nil {
return err
}
for {
// Get the next item
raw := evals.Next()
if raw == nil {
break
}
// Prepare the request struct
eval := raw.(*structs.Evaluation)
// Write out the evaluation
sink.Write([]byte{byte(EvalSnapshot)})
if err := encoder.Encode(eval); err != nil {
return err
}
}
return nil
}
func (s *nomadSnapshot) persistAllocs(sink raft.SnapshotSink,
encoder *codec.Encoder) error {
// Get all the allocations
allocs, err := s.snap.Allocs()
if err != nil {
return err
}
for {
// Get the next item
raw := allocs.Next()
if raw == nil {
break
}
// Prepare the request struct
alloc := raw.(*structs.Allocation)
// Write out the evaluation
sink.Write([]byte{byte(AllocSnapshot)})
if err := encoder.Encode(alloc); err != nil {
return err
}
}
return nil
}
// Release is a no-op, as we just need to GC the pointer
// to the state store snapshot. There is nothing to explicitly
// cleanup.
func (s *nomadSnapshot) Release() {}