dendrite/internal/caching/impl_ristretto.go
Neil Alexander 3ea21273bc
Ristretto cache (#2563)
* Try Ristretto cache

* Tweak

* It's beautiful

* Update GMSL

* More strict keyable interface

* Fix that some more

* Make less panicky

* Don't enforce mutability checks for now

* Determine mutability using deep equality

* Tweaks

* Namespace keys

* Make federation caches mutable

* Update cost estimation, add metric

* Update GMSL

* Estimate cost for metrics better

* Reduce counters a bit

* Try caching events

* Some guards

* Try again

* Try this

* Use separate caches for hopefully better hash distribution

* Fix bug with admitting events into cache

* Try to fix bugs

* Check nil

* Try that again

* Preserve order jeezo this is messy

* thanks VS Code for doing exactly the wrong thing

* Try this again

* Be more specific

* aaaaargh

* One more time

* That might be better

* Stronger sorting

* Cache expiries, async publishing of EDUs

* Put it back

* Use a shared cache again

* Cost estimation fixes

* Update ristretto

* Reduce counters a bit

* Clean up a bit

* Update GMSL

* 1GB

* Configurable cache sizees

* Tweaks

* Add `config.DataUnit` for specifying friendly cache sizes

* Various tweaks

* Update GMSL

* Add back some lazy loading caching

* Include key in cost

* Include key in cost

* Tweak max age handling, config key name

* Only register prometheus metrics if requested

* Review comments @S7evinK

* Don't return errors when creating caches (it is better just to crash since otherwise we'll `nil`-pointer exception everywhere)

* Review comments

* Update sample configs

* Update GHA Workflow

* Update Complement images to Go 1.18

* Remove the cache test from the federation API as we no longer guarantee immediate cache admission

* Don't check the caches in the renewal test

* Possibly fix the upgrade tests

* Update to matrix-org/gomatrixserverlib#322

* Update documentation to refer to Go 1.18
2022-07-11 14:31:31 +01:00

200 lines
5.8 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: 1e5, // 10x number of expected cache items, affects bloom filter size, gives us room for 10,000 currently
BufferItems: 64, // recommended by the ristretto godocs as a sane buffer size value
MaxCost: int64(maxCost),
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
}