dendrite/internal/caching/impl_ristretto.go
Neil Alexander 99b696e775
Tweak cache counters (#2575)
* Tweak cache counters

This makes the number of counters relative to the
maximum cache size. Since the counters
effectively manage the size of the bloom filter,
larger caches need more counters and smaller
caches need less.

10 counters per 1KB data means that the default
cache size of 1GB should result in a bloom filter
and TinyLRU admission set of about 16MB
estimated.

* Remove line left by accident
2022-07-18 14:49:41 +01:00

201 lines
5.9 KiB
Go

// Copyright 2022 The Matrix.org Foundation C.I.C.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package caching
import (
"fmt"
"reflect"
"time"
"unsafe"
"github.com/dgraph-io/ristretto"
"github.com/dgraph-io/ristretto/z"
"github.com/matrix-org/dendrite/roomserver/types"
"github.com/matrix-org/dendrite/setup/config"
"github.com/matrix-org/gomatrixserverlib"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
)
const (
roomVersionsCache byte = iota + 1
serverKeysCache
roomNIDsCache
roomIDsCache
roomEventsCache
roomInfosCache
federationPDUsCache
federationEDUsCache
spaceSummaryRoomsCache
lazyLoadingCache
)
func NewRistrettoCache(maxCost config.DataUnit, maxAge time.Duration, enablePrometheus bool) *Caches {
cache, err := ristretto.NewCache(&ristretto.Config{
NumCounters: int64((maxCost / 1024) * 10), // 10 counters per 1KB data, affects bloom filter size
BufferItems: 64, // recommended by the ristretto godocs as a sane buffer size value
MaxCost: int64(maxCost), // max cost is in bytes, as per the Dendrite config
Metrics: true,
KeyToHash: func(key interface{}) (uint64, uint64) {
return z.KeyToHash(key)
},
})
if err != nil {
panic(err)
}
if enablePrometheus {
promauto.NewGaugeFunc(prometheus.GaugeOpts{
Namespace: "dendrite",
Subsystem: "caching_ristretto",
Name: "ratio",
}, func() float64 {
return float64(cache.Metrics.Ratio())
})
promauto.NewGaugeFunc(prometheus.GaugeOpts{
Namespace: "dendrite",
Subsystem: "caching_ristretto",
Name: "cost",
}, func() float64 {
return float64(cache.Metrics.CostAdded() - cache.Metrics.CostEvicted())
})
}
return &Caches{
RoomVersions: &RistrettoCachePartition[string, gomatrixserverlib.RoomVersion]{ // room ID -> room version
cache: cache,
Prefix: roomVersionsCache,
MaxAge: maxAge,
},
ServerKeys: &RistrettoCachePartition[string, gomatrixserverlib.PublicKeyLookupResult]{ // server name -> server keys
cache: cache,
Prefix: serverKeysCache,
Mutable: true,
MaxAge: maxAge,
},
RoomServerRoomNIDs: &RistrettoCachePartition[string, types.RoomNID]{ // room ID -> room NID
cache: cache,
Prefix: roomNIDsCache,
MaxAge: maxAge,
},
RoomServerRoomIDs: &RistrettoCachePartition[int64, string]{ // room NID -> room ID
cache: cache,
Prefix: roomIDsCache,
MaxAge: maxAge,
},
RoomServerEvents: &RistrettoCostedCachePartition[int64, *gomatrixserverlib.Event]{ // event NID -> event
&RistrettoCachePartition[int64, *gomatrixserverlib.Event]{
cache: cache,
Prefix: roomEventsCache,
MaxAge: maxAge,
},
},
RoomInfos: &RistrettoCachePartition[string, *types.RoomInfo]{ // room ID -> room info
cache: cache,
Prefix: roomInfosCache,
Mutable: true,
MaxAge: maxAge,
},
FederationPDUs: &RistrettoCostedCachePartition[int64, *gomatrixserverlib.HeaderedEvent]{ // queue NID -> PDU
&RistrettoCachePartition[int64, *gomatrixserverlib.HeaderedEvent]{
cache: cache,
Prefix: federationPDUsCache,
Mutable: true,
MaxAge: lesserOf(time.Hour/2, maxAge),
},
},
FederationEDUs: &RistrettoCostedCachePartition[int64, *gomatrixserverlib.EDU]{ // queue NID -> EDU
&RistrettoCachePartition[int64, *gomatrixserverlib.EDU]{
cache: cache,
Prefix: federationEDUsCache,
Mutable: true,
MaxAge: lesserOf(time.Hour/2, maxAge),
},
},
SpaceSummaryRooms: &RistrettoCachePartition[string, gomatrixserverlib.MSC2946SpacesResponse]{ // room ID -> space response
cache: cache,
Prefix: spaceSummaryRoomsCache,
Mutable: true,
MaxAge: maxAge,
},
LazyLoading: &RistrettoCachePartition[lazyLoadingCacheKey, string]{ // composite key -> event ID
cache: cache,
Prefix: lazyLoadingCache,
Mutable: true,
MaxAge: maxAge,
},
}
}
type RistrettoCostedCachePartition[k keyable, v costable] struct {
*RistrettoCachePartition[k, v]
}
func (c *RistrettoCostedCachePartition[K, V]) Set(key K, value V) {
cost := value.CacheCost()
c.setWithCost(key, value, int64(cost))
}
type RistrettoCachePartition[K keyable, V any] struct {
cache *ristretto.Cache
Prefix byte
Mutable bool
MaxAge time.Duration
}
func (c *RistrettoCachePartition[K, V]) setWithCost(key K, value V, cost int64) {
bkey := fmt.Sprintf("%c%v", c.Prefix, key)
if !c.Mutable {
if v, ok := c.cache.Get(bkey); ok && v != nil && !reflect.DeepEqual(v, value) {
panic(fmt.Sprintf("invalid use of immutable cache tries to change value of %v from %v to %v", key, v, value))
}
}
c.cache.SetWithTTL(bkey, value, int64(len(bkey))+cost, c.MaxAge)
}
func (c *RistrettoCachePartition[K, V]) Set(key K, value V) {
var cost int64
if cv, ok := any(value).(string); ok {
cost = int64(len(cv))
} else {
cost = int64(unsafe.Sizeof(value))
}
c.setWithCost(key, value, cost)
}
func (c *RistrettoCachePartition[K, V]) Unset(key K) {
bkey := fmt.Sprintf("%c%v", c.Prefix, key)
if !c.Mutable {
panic(fmt.Sprintf("invalid use of immutable cache tries to unset value of %v", key))
}
c.cache.Del(bkey)
}
func (c *RistrettoCachePartition[K, V]) Get(key K) (value V, ok bool) {
bkey := fmt.Sprintf("%c%v", c.Prefix, key)
v, ok := c.cache.Get(bkey)
if !ok || v == nil {
var empty V
return empty, false
}
value, ok = v.(V)
return
}
func lesserOf(a, b time.Duration) time.Duration {
if a < b {
return a
}
return b
}