LRU cache for room versions in RS query API (#976)

* Experimental LRU cache for room versions

* Don't accidentally try to type-assert nil

* Also reduce hits on query API

* Use hashicorp implementation which mutexes for us

* Define const for max cache entries

* Rename to be specifically immutable, panic if we try to mutate a cache entry

* Review comments

* Remove nil guards, give roomserver integration test a cache

* go mod tidy
This commit is contained in:
Neil Alexander 2020-04-22 13:00:05 +01:00 committed by GitHub
parent 71f9d35b7c
commit a466e9e9cc
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
7 changed files with 112 additions and 22 deletions

View file

@ -28,6 +28,7 @@ import (
"net/http"
"github.com/matrix-org/dendrite/common/caching"
"github.com/matrix-org/dendrite/common/test"
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/gomatrixserverlib"
@ -253,6 +254,11 @@ func testRoomserver(input []string, wantOutput []string, checkQueries func(api.R
panic(err)
}
cache, err := caching.NewImmutableInMemoryLRUCache()
if err != nil {
panic(err)
}
doInput := func() {
fmt.Printf("Roomserver is ready to receive input, sending %d events\n", len(input))
if err = writeToRoomServer(input, cfg.RoomServerURL()); err != nil {
@ -270,7 +276,7 @@ func testRoomserver(input []string, wantOutput []string, checkQueries func(api.R
cmd.Args = []string{"dendrite-room-server", "--config", filepath.Join(dir, test.ConfigFile)}
gotOutput, err := runAndReadFromTopic(cmd, cfg.RoomServerURL()+"/metrics", doInput, outputTopic, len(wantOutput), func() {
queryAPI, _ := api.NewRoomserverQueryAPIHTTP("http://"+string(cfg.Listen.RoomServer), &http.Client{Timeout: timeoutHTTP})
queryAPI, _ := api.NewRoomserverQueryAPIHTTP("http://"+string(cfg.Listen.RoomServer), &http.Client{Timeout: timeoutHTTP}, cache)
checkQueries(queryAPI)
})
if err != nil {

View file

@ -23,6 +23,7 @@ import (
"golang.org/x/crypto/ed25519"
"github.com/matrix-org/dendrite/common/caching"
"github.com/matrix-org/dendrite/common/keydb"
"github.com/matrix-org/dendrite/internal/sqlutil"
"github.com/matrix-org/gomatrixserverlib"
@ -56,6 +57,7 @@ type BaseDendrite struct {
APIMux *mux.Router
httpClient *http.Client
Cfg *config.Dendrite
ImmutableCache caching.ImmutableCache
KafkaConsumer sarama.Consumer
KafkaProducer sarama.SyncProducer
}
@ -83,10 +85,16 @@ func NewBaseDendrite(cfg *config.Dendrite, componentName string) *BaseDendrite {
kafkaConsumer, kafkaProducer = setupKafka(cfg)
}
cache, err := caching.NewImmutableInMemoryLRUCache()
if err != nil {
logrus.WithError(err).Warnf("Failed to create cache")
}
return &BaseDendrite{
componentName: componentName,
tracerCloser: closer,
Cfg: cfg,
ImmutableCache: cache,
APIMux: mux.NewRouter().UseEncodedPath(),
httpClient: &http.Client{Timeout: HTTPClientTimeout},
KafkaConsumer: kafkaConsumer,
@ -116,7 +124,6 @@ func (b *BaseDendrite) CreateHTTPRoomserverAPIs() (
roomserverAPI.RoomserverInputAPI,
roomserverAPI.RoomserverQueryAPI,
) {
alias, err := roomserverAPI.NewRoomserverAliasAPIHTTP(b.Cfg.RoomServerURL(), b.httpClient)
if err != nil {
logrus.WithError(err).Panic("NewRoomserverAliasAPIHTTP failed")
@ -125,7 +132,7 @@ func (b *BaseDendrite) CreateHTTPRoomserverAPIs() (
if err != nil {
logrus.WithError(err).Panic("NewRoomserverInputAPIHTTP failed", b.httpClient)
}
query, err := roomserverAPI.NewRoomserverQueryAPIHTTP(b.Cfg.RoomServerURL(), b.httpClient)
query, err := roomserverAPI.NewRoomserverQueryAPIHTTP(b.Cfg.RoomServerURL(), b.httpClient, b.ImmutableCache)
if err != nil {
logrus.WithError(err).Panic("NewRoomserverQueryAPIHTTP failed", b.httpClient)
}

View file

@ -0,0 +1,12 @@
package caching
import "github.com/matrix-org/gomatrixserverlib"
const (
RoomVersionMaxCacheEntries = 128
)
type ImmutableCache interface {
GetRoomVersion(roomId string) (gomatrixserverlib.RoomVersion, bool)
StoreRoomVersion(roomId string, roomVersion gomatrixserverlib.RoomVersion)
}

View file

@ -0,0 +1,43 @@
package caching
import (
"fmt"
lru "github.com/hashicorp/golang-lru"
"github.com/matrix-org/gomatrixserverlib"
)
type ImmutableInMemoryLRUCache struct {
roomVersions *lru.Cache
}
func NewImmutableInMemoryLRUCache() (*ImmutableInMemoryLRUCache, error) {
roomVersionCache, rvErr := lru.New(RoomVersionMaxCacheEntries)
if rvErr != nil {
return nil, rvErr
}
return &ImmutableInMemoryLRUCache{
roomVersions: roomVersionCache,
}, nil
}
func checkForInvalidMutation(cache *lru.Cache, key string, value interface{}) {
if peek, ok := cache.Peek(key); ok && peek != value {
panic(fmt.Sprintf("invalid use of immutable cache tries to mutate existing value of %q", key))
}
}
func (c *ImmutableInMemoryLRUCache) GetRoomVersion(roomID string) (gomatrixserverlib.RoomVersion, bool) {
val, found := c.roomVersions.Get(roomID)
if found && val != nil {
if roomVersion, ok := val.(gomatrixserverlib.RoomVersion); ok {
return roomVersion, true
}
}
return "", false
}
func (c *ImmutableInMemoryLRUCache) StoreRoomVersion(roomID string, roomVersion gomatrixserverlib.RoomVersion) {
checkForInvalidMutation(c.roomVersions, roomID, roomVersion)
c.roomVersions.Add(roomID, roomVersion)
}

View file

@ -21,6 +21,7 @@ import (
"errors"
"net/http"
"github.com/matrix-org/dendrite/common/caching"
commonHTTP "github.com/matrix-org/dendrite/common/http"
"github.com/matrix-org/gomatrixserverlib"
opentracing "github.com/opentracing/opentracing-go"
@ -411,16 +412,17 @@ const RoomserverQueryRoomVersionForRoomPath = "/api/roomserver/queryRoomVersionF
// NewRoomserverQueryAPIHTTP creates a RoomserverQueryAPI implemented by talking to a HTTP POST API.
// If httpClient is nil an error is returned
func NewRoomserverQueryAPIHTTP(roomserverURL string, httpClient *http.Client) (RoomserverQueryAPI, error) {
func NewRoomserverQueryAPIHTTP(roomserverURL string, httpClient *http.Client, cache caching.ImmutableCache) (RoomserverQueryAPI, error) {
if httpClient == nil {
return nil, errors.New("NewRoomserverQueryAPIHTTP: httpClient is <nil>")
}
return &httpRoomserverQueryAPI{roomserverURL, httpClient}, nil
return &httpRoomserverQueryAPI{roomserverURL, httpClient, cache}, nil
}
type httpRoomserverQueryAPI struct {
roomserverURL string
httpClient *http.Client
immutableCache caching.ImmutableCache
}
// QueryLatestEventsAndState implements RoomserverQueryAPI
@ -585,9 +587,18 @@ func (h *httpRoomserverQueryAPI) QueryRoomVersionForRoom(
request *QueryRoomVersionForRoomRequest,
response *QueryRoomVersionForRoomResponse,
) error {
if roomVersion, ok := h.immutableCache.GetRoomVersion(request.RoomID); ok {
response.RoomVersion = roomVersion
return nil
}
span, ctx := opentracing.StartSpanFromContext(ctx, "QueryRoomVersionForRoom")
defer span.Finish()
apiURL := h.roomserverURL + RoomserverQueryRoomVersionForRoomPath
return commonHTTP.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
err := commonHTTP.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
if err == nil {
h.immutableCache.StoreRoomVersion(request.RoomID, response.RoomVersion)
}
return err
}

View file

@ -22,6 +22,7 @@ import (
"net/http"
"github.com/matrix-org/dendrite/common"
"github.com/matrix-org/dendrite/common/caching"
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/roomserver/auth"
"github.com/matrix-org/dendrite/roomserver/state"
@ -98,6 +99,7 @@ type RoomserverQueryAPIDatabase interface {
// RoomserverQueryAPI is an implementation of api.RoomserverQueryAPI
type RoomserverQueryAPI struct {
DB RoomserverQueryAPIDatabase
ImmutableCache caching.ImmutableCache
}
// QueryLatestEventsAndState implements api.RoomserverQueryAPI
@ -896,11 +898,17 @@ func (r *RoomserverQueryAPI) QueryRoomVersionForRoom(
request *api.QueryRoomVersionForRoomRequest,
response *api.QueryRoomVersionForRoomResponse,
) error {
if roomVersion, ok := r.ImmutableCache.GetRoomVersion(request.RoomID); ok {
response.RoomVersion = roomVersion
return nil
}
roomVersion, err := r.DB.GetRoomVersionForRoom(ctx, request.RoomID)
if err != nil {
return err
}
response.RoomVersion = roomVersion
r.ImmutableCache.StoreRoomVersion(request.RoomID, response.RoomVersion)
return nil
}

View file

@ -48,7 +48,10 @@ func SetupRoomServerComponent(
inputAPI.SetupHTTP(http.DefaultServeMux)
queryAPI := query.RoomserverQueryAPI{DB: roomserverDB}
queryAPI := query.RoomserverQueryAPI{
DB: roomserverDB,
ImmutableCache: base.ImmutableCache,
}
queryAPI.SetupHTTP(http.DefaultServeMux)