Skip to content

Commit

Permalink
Rework Cache interface to isolate it from streamState and make it mor…
Browse files Browse the repository at this point in the history 
…e uniform between sotw and delta

Signed-off-by: Valerian Roche <[email protected]>
  • Loading branch information
@valerian-roche
valerian-roche committed Aug 25, 2022
1 parent cde5ba5 commit a36df79
Show file tree
Hide file tree
Showing 15 changed files with 222 additions and 229 deletions.
26 changes: 23 additions & 3 deletions pkg/cache/v3/cache.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -26,7 +26,6 @@ import (
"google.golang.org/protobuf/types/known/durationpb"

"github.com/envoyproxy/go-control-plane/pkg/cache/types"
"github.com/envoyproxy/go-control-plane/pkg/server/stream/v3"

discovery "github.com/envoyproxy/go-control-plane/envoy/service/discovery/v3"
)
Expand All @@ -37,6 +36,27 @@ type Request = discovery.DiscoveryRequest
// DeltaRequest is an alias for the delta discovery request type.
type DeltaRequest = discovery.DeltaDiscoveryRequest

// ClientState provides additional data on the client knowledge for the type matching the request
// This allows proper implementation of stateful aspects of the protocol (e.g. returning only some updated resources)
// Though the methods may return mutable parts of the state for performance reasons,
// the cache is expected to consider this state as immutable and thread safe between a watch creation and its cancellation
type ClientState interface {
// GetKnownResources returns the list of resources the clients has ACKed and their associated version.
// The versions are:
// - delta protocol: version of the specific resource set in the response
// - sotw protocol: version of the global response when the resource was last ACKed
GetKnownResources() map[string]string

// GetSubscribedResources returns the list of resources currently subscribed to by the client for the type.
// For delta it keeps track across requests
// For sotw it is a normalized view of the request resources
GetSubscribedResources() map[string]struct{}

// IsWildcard returns whether the client has a wildcard watch.
// This considers subtilities related to the current migration of wildcard definition within the protocol.
IsWildcard() bool
}

// ConfigWatcher requests watches for configuration resources by a node, last
// applied version identifier, and resource names hint. The watch should send
// the responses when they are ready. The watch can be canceled by the
Expand All @@ -50,7 +70,7 @@ type ConfigWatcher interface {
//
// Cancel is an optional function to release resources in the producer. If
// provided, the consumer may call this function multiple times.
CreateWatch(*Request, stream.StreamState, chan Response) (cancel func())
CreateWatch(*Request, ClientState, chan Response) (cancel func())

// CreateDeltaWatch returns a new open incremental xDS watch.
//
Expand All @@ -59,7 +79,7 @@ type ConfigWatcher interface {
//
// Cancel is an optional function to release resources in the producer. If
// provided, the consumer may call this function multiple times.
CreateDeltaWatch(*DeltaRequest, stream.StreamState, chan DeltaResponse) (cancel func())
CreateDeltaWatch(*DeltaRequest, ClientState, chan DeltaResponse) (cancel func())
}

// ConfigFetcher fetches configuration resources from cache
Expand Down
15 changes: 7 additions & 8 deletions pkg/cache/v3/delta.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -18,7 +18,6 @@ import (
"context"

"github.com/envoyproxy/go-control-plane/pkg/cache/types"
"github.com/envoyproxy/go-control-plane/pkg/server/stream/v3"
)

// groups together resource-related arguments for the createDeltaResponse function
Expand All @@ -28,7 +27,7 @@ type resourceContainer struct {
systemVersion string
}

func createDeltaResponse(ctx context.Context, req *DeltaRequest, state stream.StreamState, resources resourceContainer) *RawDeltaResponse {
func createDeltaResponse(ctx context.Context, req *DeltaRequest, state ClientState, resources resourceContainer) *RawDeltaResponse {
// variables to build our response with
var nextVersionMap map[string]string
var filtered []types.Resource
Expand All @@ -37,7 +36,7 @@ func createDeltaResponse(ctx context.Context, req *DeltaRequest, state stream.St
// If we are handling a wildcard request, we want to respond with all resources
switch {
case state.IsWildcard():
if len(state.GetResourceVersions()) == 0 {
if len(state.GetKnownResources()) == 0 {
filtered = make([]types.Resource, 0, len(resources.resourceMap))
}
nextVersionMap = make(map[string]string, len(resources.resourceMap))
Expand All @@ -46,25 +45,25 @@ func createDeltaResponse(ctx context.Context, req *DeltaRequest, state stream.St
// we can just set it here to be used for comparison later
version := resources.versionMap[name]
nextVersionMap[name] = version
prevVersion, found := state.GetResourceVersions()[name]
prevVersion, found := state.GetKnownResources()[name]
if !found || (prevVersion != version) {
filtered = append(filtered, r)
}
}

// Compute resources for removal
// The resource version can be set to "" here to trigger a removal even if never returned before
for name := range state.GetResourceVersions() {
for name := range state.GetKnownResources() {
if _, ok := resources.resourceMap[name]; !ok {
toRemove = append(toRemove, name)
}
}
default:
nextVersionMap = make(map[string]string, len(state.GetSubscribedResourceNames()))
nextVersionMap = make(map[string]string, len(state.GetSubscribedResources()))
// state.GetResourceVersions() may include resources no longer subscribed
// In the current code this gets silently cleaned when updating the version map
for name := range state.GetSubscribedResourceNames() {
prevVersion, found := state.GetResourceVersions()[name]
for name := range state.GetSubscribedResources() {
prevVersion, found := state.GetKnownResources()[name]
if r, ok := resources.resourceMap[name]; ok {
nextVersion := resources.versionMap[name]
if prevVersion != nextVersion {
Expand Down
46 changes: 21 additions & 25 deletions pkg/cache/v3/delta_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3,12 +3,12 @@ package cache_test
import (
"context"
"fmt"
"reflect"
"testing"
"time"

"github.com/google/go-cmp/cmp"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
"google.golang.org/protobuf/testing/protocmp"

core "github.com/envoyproxy/go-control-plane/envoy/config/core/v3"
Expand All @@ -35,13 +35,14 @@ func TestSnapshotCacheDeltaWatch(t *testing.T) {
// Make our initial request as a wildcard to get all resources and make sure the wildcard requesting works as intended
for _, typ := range testTypes {
watches[typ] = make(chan cache.DeltaResponse, 1)
state := stream.NewStreamState(true, nil)
c.CreateDeltaWatch(&discovery.DeltaDiscoveryRequest{
Node: &core.Node{
Id: "node",
},
TypeUrl: typ,
ResourceNamesSubscribe: names[typ],
}, stream.NewStreamState(true, nil), watches[typ])
}, &state, watches[typ])
}

if err := c.SetSnapshot(context.Background(), key, fixture.snapshot()); err != nil {
Expand Down Expand Up @@ -69,15 +70,15 @@ func TestSnapshotCacheDeltaWatch(t *testing.T) {
watches[typ] = make(chan cache.DeltaResponse, 1)
state := stream.NewStreamState(false, versionMap[typ])
for resource := range versionMap[typ] {
state.GetSubscribedResourceNames()[resource] = struct{}{}
state.GetSubscribedResources()[resource] = struct{}{}
}
c.CreateDeltaWatch(&discovery.DeltaDiscoveryRequest{
Node: &core.Node{
Id: "node",
},
TypeUrl: typ,
ResourceNamesSubscribe: names[typ],
}, state, watches[typ])
}, &state, watches[typ])
}

if count := c.GetStatusInfo(key).GetNumDeltaWatches(); count != len(testTypes) {
Expand Down Expand Up @@ -123,12 +124,10 @@ func TestDeltaRemoveResources(t *testing.T) {
Id: "node",
},
TypeUrl: typ,
}, *streams[typ], watches[typ])
}, streams[typ], watches[typ])
}

if err := c.SetSnapshot(context.Background(), key, fixture.snapshot()); err != nil {
t.Fatal(err)
}
require.NoError(t, c.SetSnapshot(context.Background(), key, fixture.snapshot()))

for _, typ := range testTypes {
t.Run(typ, func(t *testing.T) {
Expand All @@ -139,7 +138,7 @@ func TestDeltaRemoveResources(t *testing.T) {
nextVersionMap := out.GetNextVersionMap()
streams[typ].SetResourceVersions(nextVersionMap)
case <-time.After(time.Second):
t.Fatal("failed to receive a snapshot response")
require.Fail(t, "failed to receive a snapshot response")
}
})
}
Expand All @@ -152,20 +151,17 @@ func TestDeltaRemoveResources(t *testing.T) {
Node: &core.Node{
Id: "node",
},
TypeUrl: typ,
}, *streams[typ], watches[typ])
TypeUrl: typ,
ResponseNonce: "nonce",
}, streams[typ], watches[typ])
}

if count := c.GetStatusInfo(key).GetNumDeltaWatches(); count != len(testTypes) {
t.Errorf("watches should be created for the latest version, saw %d watches expected %d", count, len(testTypes))
}
assert.Equal(t, len(testTypes), c.GetStatusInfo(key).GetNumDeltaWatches(), "watches should be created for the latest version")

// set a partially versioned snapshot with no endpoints
snapshot2 := fixture.snapshot()
snapshot2.Resources[types.Endpoint] = cache.NewResources(fixture.version2, []types.Resource{})
if err := c.SetSnapshot(context.Background(), key, snapshot2); err != nil {
t.Fatal(err)
}
require.NoError(t, c.SetSnapshot(context.Background(), key, snapshot2))

// validate response for endpoints
select {
Expand All @@ -176,11 +172,9 @@ func TestDeltaRemoveResources(t *testing.T) {
nextVersionMap := out.GetNextVersionMap()

// make sure the version maps are different since we no longer are tracking any endpoint resources
if reflect.DeepEqual(streams[testTypes[0]].GetResourceVersions(), nextVersionMap) {
t.Fatalf("versionMap for the endpoint resource type did not change, received: %v, instead of an empty map", nextVersionMap)
}
require.Equal(t, nextVersionMap, streams[testTypes[0]].GetKnownResources(), "versionMap for the endpoint resource type did not change")
case <-time.After(time.Second):
t.Fatal("failed to receive snapshot response")
assert.Fail(t, "failed to receive snapshot response")
}
}

Expand All @@ -203,13 +197,14 @@ func TestConcurrentSetDeltaWatch(t *testing.T) {
t.Fatalf("snapshot failed: %s", err)
}
} else {
state := stream.NewStreamState(false, make(map[string]string))
cancel := c.CreateDeltaWatch(&discovery.DeltaDiscoveryRequest{
Node: &core.Node{
Id: id,
},
TypeUrl: rsrc.EndpointType,
ResourceNamesSubscribe: []string{clusterName},
}, stream.NewStreamState(false, make(map[string]string)), responses)
}, &state, responses)

defer cancel()
}
Expand All @@ -226,14 +221,14 @@ func TestSnapshotDeltaCacheWatchTimeout(t *testing.T) {
// Create a non-buffered channel that will block sends.
watchCh := make(chan cache.DeltaResponse)
state := stream.NewStreamState(false, nil)
state.SetSubscribedResourceNames(map[string]struct{}{names[rsrc.EndpointType][0]: {}})
state.SetSubscribedResources(map[string]struct{}{names[rsrc.EndpointType][0]: {}})
c.CreateDeltaWatch(&discovery.DeltaDiscoveryRequest{
Node: &core.Node{
Id: key,
},
TypeUrl: rsrc.EndpointType,
ResourceNamesSubscribe: names[rsrc.EndpointType],
}, state, watchCh)
}, &state, watchCh)

// The first time we set the snapshot without consuming from the blocking channel, so this should time out.
ctx, cancel := context.WithTimeout(context.Background(), time.Millisecond)
Expand Down Expand Up @@ -269,13 +264,14 @@ func TestSnapshotCacheDeltaWatchCancel(t *testing.T) {
c := cache.NewSnapshotCache(true, group{}, logger{t: t})
for _, typ := range testTypes {
responses := make(chan cache.DeltaResponse, 1)
state := stream.NewStreamState(false, make(map[string]string))
cancel := c.CreateDeltaWatch(&discovery.DeltaDiscoveryRequest{
Node: &core.Node{
Id: key,
},
TypeUrl: typ,
ResourceNamesSubscribe: names[typ],
}, stream.NewStreamState(false, make(map[string]string)), responses)
}, &state, responses)

// Cancel the watch
cancel()
Expand Down
21 changes: 10 additions & 11 deletions pkg/cache/v3/linear.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -24,7 +24,6 @@ import (

"github.com/envoyproxy/go-control-plane/pkg/cache/types"
"github.com/envoyproxy/go-control-plane/pkg/log"
"github.com/envoyproxy/go-control-plane/pkg/server/stream/v3"
)

type watches = map[chan Response]struct{}
Expand Down Expand Up @@ -164,20 +163,20 @@ func (cache *LinearCache) notifyAll(modified map[string]struct{}) {
}

for id, watch := range cache.deltaWatches {
if !watch.StreamState.WatchesResources(modified) {
if !watch.WatchesResources(modified) {
continue
}

res := cache.respondDelta(watch.Request, watch.Response, watch.StreamState)
res := cache.respondDelta(watch.Request, watch.Response, watch.clientState)
if res != nil {
delete(cache.deltaWatches, id)
}
}
}
}

func (cache *LinearCache) respondDelta(request *DeltaRequest, value chan DeltaResponse, state stream.StreamState) *RawDeltaResponse {
resp := createDeltaResponse(context.Background(), request, state, resourceContainer{
func (cache *LinearCache) respondDelta(request *DeltaRequest, value chan DeltaResponse, clientState ClientState) *RawDeltaResponse {
resp := createDeltaResponse(context.Background(), request, clientState, resourceContainer{
resourceMap: cache.resources,
versionMap: cache.versionMap,
systemVersion: cache.getVersion(),
Expand All @@ -187,7 +186,7 @@ func (cache *LinearCache) respondDelta(request *DeltaRequest, value chan DeltaRe
if len(resp.Resources) > 0 || len(resp.RemovedResources) > 0 {
if cache.log != nil {
cache.log.Debugf("[linear cache] node: %s, sending delta response with resources: %v removed resources %v wildcard: %t",
request.GetNode().GetId(), resp.Resources, resp.RemovedResources, state.IsWildcard())
request.GetNode().GetId(), resp.Resources, resp.RemovedResources, clientState.IsWildcard())
}
value <- resp
return resp
Expand Down Expand Up @@ -298,7 +297,7 @@ func (cache *LinearCache) GetResources() map[string]types.Resource {
return resources
}

func (cache *LinearCache) CreateWatch(request *Request, streamState stream.StreamState, value chan Response) func() {
func (cache *LinearCache) CreateWatch(request *Request, clientState ClientState, value chan Response) func() {
if request.TypeUrl != cache.typeURL {
value <- nil
return nil
Expand Down Expand Up @@ -371,7 +370,7 @@ func (cache *LinearCache) CreateWatch(request *Request, streamState stream.Strea
}
}

func (cache *LinearCache) CreateDeltaWatch(request *DeltaRequest, state stream.StreamState, value chan DeltaResponse) func() {
func (cache *LinearCache) CreateDeltaWatch(request *DeltaRequest, clientState ClientState, value chan DeltaResponse) func() {
cache.mu.Lock()
defer cache.mu.Unlock()

Expand All @@ -388,18 +387,18 @@ func (cache *LinearCache) CreateDeltaWatch(request *DeltaRequest, state stream.S
cache.log.Errorf("failed to update version map: %v", err)
}
}
response := cache.respondDelta(request, value, state)
response := cache.respondDelta(request, value, clientState)

// if respondDelta returns nil this means that there is no change in any resource version
// create a new watch accordingly
if response == nil {
watchID := cache.nextDeltaWatchID()
if cache.log != nil {
cache.log.Infof("[linear cache] open delta watch ID:%d for %s Resources:%v, system version %q", watchID,
cache.typeURL, state.GetSubscribedResourceNames(), cache.getVersion())
cache.typeURL, clientState.GetSubscribedResources(), cache.getVersion())
}

cache.deltaWatches[watchID] = DeltaResponseWatch{Request: request, Response: value, StreamState: state}
cache.deltaWatches[watchID] = DeltaResponseWatch{Request: request, Response: value, clientState: clientState}

return cache.cancelDeltaWatch(watchID)
}
Expand Down
Loading

0 comments on commit a36df79

Please sign in to comment.