forked from hashicorp/nomad
/
node_endpoint.go
774 lines (678 loc) · 20.8 KB
/
node_endpoint.go
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package nomad
import (
"fmt"
"sync"
"time"
"github.com/armon/go-metrics"
"github.com/hashicorp/go-memdb"
"github.com/hashicorp/nomad/nomad/state"
"github.com/hashicorp/nomad/nomad/structs"
"github.com/hashicorp/nomad/nomad/watch"
)
const (
// batchUpdateInterval is how long we wait to batch updates
batchUpdateInterval = 50 * time.Millisecond
)
// Node endpoint is used for client interactions
type Node struct {
srv *Server
// updates holds pending client status updates for allocations
updates []*structs.Allocation
// updateFuture is used to wait for the pending batch update
// to complete. This may be nil if no batch is pending.
updateFuture *batchFuture
// updateTimer is the timer that will trigger the next batch
// update, and may be nil if there is no batch pending.
updateTimer *time.Timer
// updatesLock synchronizes access to the updates list,
// the future and the timer.
updatesLock sync.Mutex
}
// Register is used to upsert a client that is available for scheduling
func (n *Node) Register(args *structs.NodeRegisterRequest, reply *structs.NodeUpdateResponse) error {
if done, err := n.srv.forward("Node.Register", args, args, reply); done {
return err
}
defer metrics.MeasureSince([]string{"nomad", "client", "register"}, time.Now())
// Validate the arguments
if args.Node == nil {
return fmt.Errorf("missing node for client registration")
}
if args.Node.ID == "" {
return fmt.Errorf("missing node ID for client registration")
}
if args.Node.Datacenter == "" {
return fmt.Errorf("missing datacenter for client registration")
}
if args.Node.Name == "" {
return fmt.Errorf("missing node name for client registration")
}
// Default the status if none is given
if args.Node.Status == "" {
args.Node.Status = structs.NodeStatusInit
}
if !structs.ValidNodeStatus(args.Node.Status) {
return fmt.Errorf("invalid status for node")
}
// Compute the node class
if err := args.Node.ComputeClass(); err != nil {
return fmt.Errorf("failed to computed node class: %v", err)
}
// Commit this update via Raft
_, index, err := n.srv.raftApply(structs.NodeRegisterRequestType, args)
if err != nil {
n.srv.logger.Printf("[ERR] nomad.client: Register failed: %v", err)
return err
}
reply.NodeModifyIndex = index
// Check if we should trigger evaluations
if structs.ShouldDrainNode(args.Node.Status) {
evalIDs, evalIndex, err := n.createNodeEvals(args.Node.ID, index)
if err != nil {
n.srv.logger.Printf("[ERR] nomad.client: eval creation failed: %v", err)
return err
}
reply.EvalIDs = evalIDs
reply.EvalCreateIndex = evalIndex
}
// Check if we need to setup a heartbeat
if !args.Node.TerminalStatus() {
ttl, err := n.srv.resetHeartbeatTimer(args.Node.ID)
if err != nil {
n.srv.logger.Printf("[ERR] nomad.client: heartbeat reset failed: %v", err)
return err
}
reply.HeartbeatTTL = ttl
}
// Set the reply index
reply.Index = index
snap, err := n.srv.fsm.State().Snapshot()
if err != nil {
return err
}
n.srv.peerLock.RLock()
defer n.srv.peerLock.RUnlock()
if err := n.constructNodeServerInfoResponse(snap, reply); err != nil {
n.srv.logger.Printf("[ERR] nomad.client: failed to populate NodeUpdateResponse: %v", err)
return err
}
return nil
}
// updateNodeUpdateResponse assumes the n.srv.peerLock is held for reading.
func (n *Node) constructNodeServerInfoResponse(snap *state.StateSnapshot, reply *structs.NodeUpdateResponse) error {
reply.LeaderRPCAddr = n.srv.raft.Leader()
// Reply with config information required for future RPC requests
reply.Servers = make([]*structs.NodeServerInfo, 0, len(n.srv.localPeers))
for k, v := range n.srv.localPeers {
reply.Servers = append(reply.Servers,
&structs.NodeServerInfo{
RPCAdvertiseAddr: k,
RPCMajorVersion: int32(v.MajorVersion),
RPCMinorVersion: int32(v.MinorVersion),
Datacenter: v.Datacenter,
})
}
// TODO(sean@): Use an indexed node count instead
//
// Snapshot is used only to iterate over all nodes to create a node
// count to send back to Nomad Clients in their heartbeat so Clients
// can estimate the size of the cluster.
iter, err := snap.Nodes()
if err == nil {
for {
raw := iter.Next()
if raw == nil {
break
}
reply.NumNodes++
}
}
return nil
}
// Deregister is used to remove a client from the client. If a client should
// just be made unavailable for scheduling, a status update is preferred.
func (n *Node) Deregister(args *structs.NodeDeregisterRequest, reply *structs.NodeUpdateResponse) error {
if done, err := n.srv.forward("Node.Deregister", args, args, reply); done {
return err
}
defer metrics.MeasureSince([]string{"nomad", "client", "deregister"}, time.Now())
// Verify the arguments
if args.NodeID == "" {
return fmt.Errorf("missing node ID for client deregistration")
}
// Commit this update via Raft
_, index, err := n.srv.raftApply(structs.NodeDeregisterRequestType, args)
if err != nil {
n.srv.logger.Printf("[ERR] nomad.client: Deregister failed: %v", err)
return err
}
// Clear the heartbeat timer if any
n.srv.clearHeartbeatTimer(args.NodeID)
// Create the evaluations for this node
evalIDs, evalIndex, err := n.createNodeEvals(args.NodeID, index)
if err != nil {
n.srv.logger.Printf("[ERR] nomad.client: eval creation failed: %v", err)
return err
}
// Setup the reply
reply.EvalIDs = evalIDs
reply.EvalCreateIndex = evalIndex
reply.NodeModifyIndex = index
reply.Index = index
return nil
}
// UpdateStatus is used to update the status of a client node
func (n *Node) UpdateStatus(args *structs.NodeUpdateStatusRequest, reply *structs.NodeUpdateResponse) error {
if done, err := n.srv.forward("Node.UpdateStatus", args, args, reply); done {
return err
}
defer metrics.MeasureSince([]string{"nomad", "client", "update_status"}, time.Now())
// Verify the arguments
if args.NodeID == "" {
return fmt.Errorf("missing node ID for client deregistration")
}
if !structs.ValidNodeStatus(args.Status) {
return fmt.Errorf("invalid status for node")
}
// Look for the node
snap, err := n.srv.fsm.State().Snapshot()
if err != nil {
return err
}
node, err := snap.NodeByID(args.NodeID)
if err != nil {
return err
}
if node == nil {
return fmt.Errorf("node not found")
}
// Commit this update via Raft
var index uint64
if node.Status != args.Status {
_, index, err = n.srv.raftApply(structs.NodeUpdateStatusRequestType, args)
if err != nil {
n.srv.logger.Printf("[ERR] nomad.client: status update failed: %v", err)
return err
}
reply.NodeModifyIndex = index
}
// Check if we should trigger evaluations
initToReady := node.Status == structs.NodeStatusInit && args.Status == structs.NodeStatusReady
terminalToReady := node.Status == structs.NodeStatusDown && args.Status == structs.NodeStatusReady
transitionToReady := initToReady || terminalToReady
if structs.ShouldDrainNode(args.Status) || transitionToReady {
evalIDs, evalIndex, err := n.createNodeEvals(args.NodeID, index)
if err != nil {
n.srv.logger.Printf("[ERR] nomad.client: eval creation failed: %v", err)
return err
}
reply.EvalIDs = evalIDs
reply.EvalCreateIndex = evalIndex
}
// Check if we need to setup a heartbeat
if args.Status != structs.NodeStatusDown {
ttl, err := n.srv.resetHeartbeatTimer(args.NodeID)
if err != nil {
n.srv.logger.Printf("[ERR] nomad.client: heartbeat reset failed: %v", err)
return err
}
reply.HeartbeatTTL = ttl
}
// Set the reply index and leader
reply.Index = index
n.srv.peerLock.RLock()
defer n.srv.peerLock.RUnlock()
if err := n.constructNodeServerInfoResponse(snap, reply); err != nil {
n.srv.logger.Printf("[ERR] nomad.client: failed to populate NodeUpdateResponse: %v", err)
return err
}
return nil
}
// UpdateDrain is used to update the drain mode of a client node
func (n *Node) UpdateDrain(args *structs.NodeUpdateDrainRequest,
reply *structs.NodeDrainUpdateResponse) error {
if done, err := n.srv.forward("Node.UpdateDrain", args, args, reply); done {
return err
}
defer metrics.MeasureSince([]string{"nomad", "client", "update_drain"}, time.Now())
// Verify the arguments
if args.NodeID == "" {
return fmt.Errorf("missing node ID for drain update")
}
// Look for the node
snap, err := n.srv.fsm.State().Snapshot()
if err != nil {
return err
}
node, err := snap.NodeByID(args.NodeID)
if err != nil {
return err
}
if node == nil {
return fmt.Errorf("node not found")
}
// Commit this update via Raft
var index uint64
if node.Drain != args.Drain {
_, index, err = n.srv.raftApply(structs.NodeUpdateDrainRequestType, args)
if err != nil {
n.srv.logger.Printf("[ERR] nomad.client: drain update failed: %v", err)
return err
}
reply.NodeModifyIndex = index
}
// Always attempt to create Node evaluations because there may be a System
// job registered that should be evaluated.
evalIDs, evalIndex, err := n.createNodeEvals(args.NodeID, index)
if err != nil {
n.srv.logger.Printf("[ERR] nomad.client: eval creation failed: %v", err)
return err
}
reply.EvalIDs = evalIDs
reply.EvalCreateIndex = evalIndex
// Set the reply index
reply.Index = index
return nil
}
// Evaluate is used to force a re-evaluation of the node
func (n *Node) Evaluate(args *structs.NodeEvaluateRequest, reply *structs.NodeUpdateResponse) error {
if done, err := n.srv.forward("Node.Evaluate", args, args, reply); done {
return err
}
defer metrics.MeasureSince([]string{"nomad", "client", "evaluate"}, time.Now())
// Verify the arguments
if args.NodeID == "" {
return fmt.Errorf("missing node ID for evaluation")
}
// Look for the node
snap, err := n.srv.fsm.State().Snapshot()
if err != nil {
return err
}
node, err := snap.NodeByID(args.NodeID)
if err != nil {
return err
}
if node == nil {
return fmt.Errorf("node not found")
}
// Create the evaluation
evalIDs, evalIndex, err := n.createNodeEvals(args.NodeID, node.ModifyIndex)
if err != nil {
n.srv.logger.Printf("[ERR] nomad.client: eval creation failed: %v", err)
return err
}
reply.EvalIDs = evalIDs
reply.EvalCreateIndex = evalIndex
// Set the reply index
reply.Index = evalIndex
n.srv.peerLock.RLock()
defer n.srv.peerLock.RUnlock()
if err := n.constructNodeServerInfoResponse(snap, reply); err != nil {
n.srv.logger.Printf("[ERR] nomad.client: failed to populate NodeUpdateResponse: %v", err)
return err
}
return nil
}
// GetNode is used to request information about a specific node
func (n *Node) GetNode(args *structs.NodeSpecificRequest,
reply *structs.SingleNodeResponse) error {
if done, err := n.srv.forward("Node.GetNode", args, args, reply); done {
return err
}
defer metrics.MeasureSince([]string{"nomad", "client", "get_node"}, time.Now())
// Setup the blocking query
opts := blockingOptions{
queryOpts: &args.QueryOptions,
queryMeta: &reply.QueryMeta,
watch: watch.NewItems(watch.Item{Node: args.NodeID}),
run: func() error {
// Verify the arguments
if args.NodeID == "" {
return fmt.Errorf("missing node ID")
}
// Look for the node
snap, err := n.srv.fsm.State().Snapshot()
if err != nil {
return err
}
out, err := snap.NodeByID(args.NodeID)
if err != nil {
return err
}
// Setup the output
reply.Node = out
if out != nil {
reply.Index = out.ModifyIndex
} else {
// Use the last index that affected the nodes table
index, err := snap.Index("nodes")
if err != nil {
return err
}
reply.Index = index
}
// Set the query response
n.srv.setQueryMeta(&reply.QueryMeta)
return nil
}}
return n.srv.blockingRPC(&opts)
}
// GetAllocs is used to request allocations for a specific node
func (n *Node) GetAllocs(args *structs.NodeSpecificRequest,
reply *structs.NodeAllocsResponse) error {
if done, err := n.srv.forward("Node.GetAllocs", args, args, reply); done {
return err
}
defer metrics.MeasureSince([]string{"nomad", "client", "get_allocs"}, time.Now())
// Verify the arguments
if args.NodeID == "" {
return fmt.Errorf("missing node ID")
}
// Setup the blocking query
opts := blockingOptions{
queryOpts: &args.QueryOptions,
queryMeta: &reply.QueryMeta,
watch: watch.NewItems(watch.Item{AllocNode: args.NodeID}),
run: func() error {
// Look for the node
snap, err := n.srv.fsm.State().Snapshot()
if err != nil {
return err
}
allocs, err := snap.AllocsByNode(args.NodeID)
if err != nil {
return err
}
// Setup the output
if len(allocs) != 0 {
reply.Allocs = allocs
for _, alloc := range allocs {
reply.Index = maxUint64(reply.Index, alloc.ModifyIndex)
}
} else {
reply.Allocs = nil
// Use the last index that affected the nodes table
index, err := snap.Index("allocs")
if err != nil {
return err
}
// Must provide non-zero index to prevent blocking
// Index 1 is impossible anyways (due to Raft internals)
if index == 0 {
reply.Index = 1
} else {
reply.Index = index
}
}
return nil
}}
return n.srv.blockingRPC(&opts)
}
// GetClientAllocs is used to request a lightweight list of alloc modify indexes
// per allocation.
func (n *Node) GetClientAllocs(args *structs.NodeSpecificRequest,
reply *structs.NodeClientAllocsResponse) error {
if done, err := n.srv.forward("Node.GetClientAllocs", args, args, reply); done {
return err
}
defer metrics.MeasureSince([]string{"nomad", "client", "get_client_allocs"}, time.Now())
// Verify the arguments
if args.NodeID == "" {
return fmt.Errorf("missing node ID")
}
// Setup the blocking query
opts := blockingOptions{
queryOpts: &args.QueryOptions,
queryMeta: &reply.QueryMeta,
watch: watch.NewItems(watch.Item{AllocNode: args.NodeID}),
run: func() error {
// Look for the node
snap, err := n.srv.fsm.State().Snapshot()
if err != nil {
return err
}
allocs, err := snap.AllocsByNode(args.NodeID)
if err != nil {
return err
}
reply.Allocs = make(map[string]uint64)
// Setup the output
if len(allocs) != 0 {
for _, alloc := range allocs {
reply.Allocs[alloc.ID] = alloc.AllocModifyIndex
reply.Index = maxUint64(reply.Index, alloc.ModifyIndex)
}
} else {
// Use the last index that affected the nodes table
index, err := snap.Index("allocs")
if err != nil {
return err
}
// Must provide non-zero index to prevent blocking
// Index 1 is impossible anyways (due to Raft internals)
if index == 0 {
reply.Index = 1
} else {
reply.Index = index
}
}
return nil
}}
return n.srv.blockingRPC(&opts)
}
// UpdateAlloc is used to update the client status of an allocation
func (n *Node) UpdateAlloc(args *structs.AllocUpdateRequest, reply *structs.GenericResponse) error {
if done, err := n.srv.forward("Node.UpdateAlloc", args, args, reply); done {
return err
}
defer metrics.MeasureSince([]string{"nomad", "client", "update_alloc"}, time.Now())
// Ensure at least a single alloc
if len(args.Alloc) == 0 {
return fmt.Errorf("must update at least one allocation")
}
// Add this to the batch
n.updatesLock.Lock()
n.updates = append(n.updates, args.Alloc...)
// Start a new batch if none
future := n.updateFuture
if future == nil {
future = NewBatchFuture()
n.updateFuture = future
n.updateTimer = time.AfterFunc(batchUpdateInterval, func() {
// Get the pending updates
n.updatesLock.Lock()
updates := n.updates
future := n.updateFuture
n.updates = nil
n.updateFuture = nil
n.updateTimer = nil
n.updatesLock.Unlock()
// Perform the batch update
n.batchUpdate(future, updates)
})
}
n.updatesLock.Unlock()
// Wait for the future
if err := future.Wait(); err != nil {
return err
}
// Setup the response
reply.Index = future.Index()
return nil
}
// batchUpdate is used to update all the allocations
func (n *Node) batchUpdate(future *batchFuture, updates []*structs.Allocation) {
// Prepare the batch update
batch := &structs.AllocUpdateRequest{
Alloc: updates,
WriteRequest: structs.WriteRequest{Region: n.srv.config.Region},
}
// Commit this update via Raft
_, index, err := n.srv.raftApply(structs.AllocClientUpdateRequestType, batch)
if err != nil {
n.srv.logger.Printf("[ERR] nomad.client: alloc update failed: %v", err)
}
// Respond to the future
future.Respond(index, err)
}
// List is used to list the available nodes
func (n *Node) List(args *structs.NodeListRequest,
reply *structs.NodeListResponse) error {
if done, err := n.srv.forward("Node.List", args, args, reply); done {
return err
}
defer metrics.MeasureSince([]string{"nomad", "client", "list"}, time.Now())
// Setup the blocking query
opts := blockingOptions{
queryOpts: &args.QueryOptions,
queryMeta: &reply.QueryMeta,
watch: watch.NewItems(watch.Item{Table: "nodes"}),
run: func() error {
// Capture all the nodes
snap, err := n.srv.fsm.State().Snapshot()
if err != nil {
return err
}
var iter memdb.ResultIterator
if prefix := args.QueryOptions.Prefix; prefix != "" {
iter, err = snap.NodesByIDPrefix(prefix)
} else {
iter, err = snap.Nodes()
}
if err != nil {
return err
}
var nodes []*structs.NodeListStub
for {
raw := iter.Next()
if raw == nil {
break
}
node := raw.(*structs.Node)
nodes = append(nodes, node.Stub())
}
reply.Nodes = nodes
// Use the last index that affected the jobs table
index, err := snap.Index("nodes")
if err != nil {
return err
}
reply.Index = index
// Set the query response
n.srv.setQueryMeta(&reply.QueryMeta)
return nil
}}
return n.srv.blockingRPC(&opts)
}
// createNodeEvals is used to create evaluations for each alloc on a node.
// Each Eval is scoped to a job, so we need to potentially trigger many evals.
func (n *Node) createNodeEvals(nodeID string, nodeIndex uint64) ([]string, uint64, error) {
// Snapshot the state
snap, err := n.srv.fsm.State().Snapshot()
if err != nil {
return nil, 0, fmt.Errorf("failed to snapshot state: %v", err)
}
// Find all the allocations for this node
allocs, err := snap.AllocsByNode(nodeID)
if err != nil {
return nil, 0, fmt.Errorf("failed to find allocs for '%s': %v", nodeID, err)
}
sysJobsIter, err := snap.JobsByScheduler("system")
if err != nil {
return nil, 0, fmt.Errorf("failed to find system jobs for '%s': %v", nodeID, err)
}
var sysJobs []*structs.Job
for job := sysJobsIter.Next(); job != nil; job = sysJobsIter.Next() {
sysJobs = append(sysJobs, job.(*structs.Job))
}
// Fast-path if nothing to do
if len(allocs) == 0 && len(sysJobs) == 0 {
return nil, 0, nil
}
// Create an eval for each JobID affected
var evals []*structs.Evaluation
var evalIDs []string
jobIDs := make(map[string]struct{})
for _, alloc := range allocs {
// Deduplicate on JobID
if _, ok := jobIDs[alloc.JobID]; ok {
continue
}
jobIDs[alloc.JobID] = struct{}{}
// Create a new eval
eval := &structs.Evaluation{
ID: structs.GenerateUUID(),
Priority: alloc.Job.Priority,
Type: alloc.Job.Type,
TriggeredBy: structs.EvalTriggerNodeUpdate,
JobID: alloc.JobID,
NodeID: nodeID,
NodeModifyIndex: nodeIndex,
Status: structs.EvalStatusPending,
}
evals = append(evals, eval)
evalIDs = append(evalIDs, eval.ID)
}
// Create an evaluation for each system job.
for _, job := range sysJobs {
// Still dedup on JobID as the node may already have the system job.
if _, ok := jobIDs[job.ID]; ok {
continue
}
jobIDs[job.ID] = struct{}{}
// Create a new eval
eval := &structs.Evaluation{
ID: structs.GenerateUUID(),
Priority: job.Priority,
Type: job.Type,
TriggeredBy: structs.EvalTriggerNodeUpdate,
JobID: job.ID,
NodeID: nodeID,
NodeModifyIndex: nodeIndex,
Status: structs.EvalStatusPending,
}
evals = append(evals, eval)
evalIDs = append(evalIDs, eval.ID)
}
// Create the Raft transaction
update := &structs.EvalUpdateRequest{
Evals: evals,
WriteRequest: structs.WriteRequest{Region: n.srv.config.Region},
}
// Commit this evaluation via Raft
// XXX: There is a risk of partial failure where the node update succeeds
// but that the EvalUpdate does not.
_, evalIndex, err := n.srv.raftApply(structs.EvalUpdateRequestType, update)
if err != nil {
return nil, 0, err
}
return evalIDs, evalIndex, nil
}
// batchFuture is used to wait on a batch update to complete
type batchFuture struct {
doneCh chan struct{}
err error
index uint64
}
// NewBatchFuture creates a new batch future
func NewBatchFuture() *batchFuture {
return &batchFuture{
doneCh: make(chan struct{}),
}
}
// Wait is used to block for the future to complete and returns the error
func (b *batchFuture) Wait() error {
<-b.doneCh
return b.err
}
// Index is used to return the index of the batch, only after Wait()
func (b *batchFuture) Index() uint64 {
return b.index
}
// Respond is used to unblock the future
func (b *batchFuture) Respond(index uint64, err error) {
b.index = index
b.err = err
close(b.doneCh)
}