open-consul/agent/consul/coordinate_endpoint.go

200 lines
5.5 KiB
Go

package consul
import (
"fmt"
"strings"
"sync"
"time"
"github.com/hashicorp/consul/acl"
"github.com/hashicorp/consul/agent/consul/state"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/go-memdb"
)
// Coordinate manages queries and updates for network coordinates.
type Coordinate struct {
// srv is a pointer back to the server.
srv *Server
// updates holds pending coordinate updates for the given nodes. This is
// keyed by node:segment so we can get a coordinate for each segment for
// servers, and we only track the latest update per node:segment.
updates map[string]*structs.CoordinateUpdateRequest
// updatesLock synchronizes access to the updates map.
updatesLock sync.Mutex
}
// NewCoordinate returns a new Coordinate endpoint.
func NewCoordinate(srv *Server) *Coordinate {
c := &Coordinate{
srv: srv,
updates: make(map[string]*structs.CoordinateUpdateRequest),
}
go c.batchUpdate()
return c
}
// batchUpdate is a long-running routine that flushes pending coordinates to the
// Raft log in batches.
func (c *Coordinate) batchUpdate() {
for {
select {
case <-time.After(c.srv.config.CoordinateUpdatePeriod):
if err := c.batchApplyUpdates(); err != nil {
c.srv.logger.Printf("[WARN] consul.coordinate: Batch update failed: %v", err)
}
case <-c.srv.shutdownCh:
return
}
}
}
// batchApplyUpdates applies all pending updates to the Raft log in a series of
// batches.
func (c *Coordinate) batchApplyUpdates() error {
// Grab the pending updates and release the lock so we can still handle
// incoming messages.
c.updatesLock.Lock()
pending := c.updates
c.updates = make(map[string]*structs.CoordinateUpdateRequest)
c.updatesLock.Unlock()
// Enforce the rate limit.
limit := c.srv.config.CoordinateUpdateBatchSize * c.srv.config.CoordinateUpdateMaxBatches
size := len(pending)
if size > limit {
c.srv.logger.Printf("[WARN] consul.coordinate: Discarded %d coordinate updates", size-limit)
size = limit
}
// Transform the map into a slice that we can feed to the Raft log in
// batches.
i := 0
updates := make(structs.Coordinates, size)
for _, update := range pending {
if !(i < size) {
break
}
updates[i] = &structs.Coordinate{
Node: update.Node,
Segment: update.Segment,
Coord: update.Coord,
}
i++
}
// Apply the updates to the Raft log in batches.
for start := 0; start < size; start += c.srv.config.CoordinateUpdateBatchSize {
end := start + c.srv.config.CoordinateUpdateBatchSize
if end > size {
end = size
}
// We set the "safe to ignore" flag on this update type so old
// servers don't crash if they see one of these.
t := structs.CoordinateBatchUpdateType | structs.IgnoreUnknownTypeFlag
slice := updates[start:end]
resp, err := c.srv.raftApply(t, slice)
if err != nil {
return err
}
if respErr, ok := resp.(error); ok {
return respErr
}
}
return nil
}
// Update inserts or updates the LAN coordinate of a node.
func (c *Coordinate) Update(args *structs.CoordinateUpdateRequest, reply *struct{}) (err error) {
if done, err := c.srv.forward("Coordinate.Update", args, args, reply); done {
return err
}
// Older clients can send coordinates with invalid numeric values like
// NaN and Inf. We guard against these coming in, though newer clients
// should never send these.
if !args.Coord.IsValid() {
return fmt.Errorf("invalid coordinate")
}
// Since this is a coordinate coming from some place else we harden this
// and look for dimensionality problems proactively.
coord, err := c.srv.serfLAN.GetCoordinate()
if err != nil {
return err
}
if !coord.IsCompatibleWith(args.Coord) {
return fmt.Errorf("incompatible coordinate")
}
// Fetch the ACL token, if any, and enforce the node policy if enabled.
rule, err := c.srv.resolveToken(args.Token)
if err != nil {
return err
}
if rule != nil && c.srv.config.ACLEnforceVersion8 {
if !rule.NodeWrite(args.Node) {
return acl.ErrPermissionDenied
}
}
// Add the coordinate to the map of pending updates.
key := fmt.Sprintf("%s:%s", args.Node, args.Segment)
c.updatesLock.Lock()
c.updates[key] = args
c.updatesLock.Unlock()
return nil
}
// ListDatacenters returns the list of datacenters and their respective nodes
// and the raw coordinates of those nodes (if no coordinates are available for
// any of the nodes, the node list may be empty).
func (c *Coordinate) ListDatacenters(args *struct{}, reply *[]structs.DatacenterMap) error {
maps, err := c.srv.router.GetDatacenterMaps()
if err != nil {
return err
}
// Strip the datacenter suffixes from all the node names.
for i := range maps {
suffix := fmt.Sprintf(".%s", maps[i].Datacenter)
for j := range maps[i].Coordinates {
node := maps[i].Coordinates[j].Node
maps[i].Coordinates[j].Node = strings.TrimSuffix(node, suffix)
}
}
*reply = maps
return nil
}
// ListNodes returns the list of nodes with their raw network coordinates (if no
// coordinates are available for a node it won't appear in this list).
func (c *Coordinate) ListNodes(args *structs.DCSpecificRequest, reply *structs.IndexedCoordinates) error {
if done, err := c.srv.forward("Coordinate.ListNodes", args, args, reply); done {
return err
}
return c.srv.blockingQuery(&args.QueryOptions,
&reply.QueryMeta,
func(ws memdb.WatchSet, state *state.Store) error {
index, coords, err := state.Coordinates(ws)
if err != nil {
return err
}
reply.Index, reply.Coordinates = index, coords
if err := c.srv.filterACL(args.Token, reply); err != nil {
return err
}
return nil
})
}