mirror of
https://github.com/1f349/dendrite.git
synced 2024-11-08 18:16:59 +00:00
Optimize PrevEventIDs
when getting thousands of backwards extremeties (#3308)
Changes how many `PrevEventIDs` we send to other servers when backfilling, capped to 100 events. Unsure about how representative this benchmark is.. ``` goos: linux goarch: amd64 pkg: github.com/matrix-org/dendrite/roomserver/api cpu: Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz │ old.txt │ new.txt │ │ sec/op │ sec/op vs base │ PrevEventIDs/Original1-8 264.9n ± 5% 237.4n ± 7% -10.36% (p=0.000 n=10) PrevEventIDs/Original10-8 3.101µ ± 4% 1.590µ ± 2% -48.72% (p=0.000 n=10) PrevEventIDs/Original100-8 44.32µ ± 2% 12.80µ ± 4% -71.11% (p=0.000 n=10) PrevEventIDs/Original500-8 263.835µ ± 4% 7.907µ ± 4% -97.00% (p=0.000 n=10) PrevEventIDs/Original1000-8 578.798µ ± 2% 7.620µ ± 2% -98.68% (p=0.000 n=10) PrevEventIDs/Original2000-8 1272.039µ ± 2% 8.241µ ± 9% -99.35% (p=0.000 n=10) geomean 43.81µ 3.659µ -91.65% │ old.txt │ new.txt │ │ B/op │ B/op vs base │ PrevEventIDs/Original1-8 72.00 ± 0% 48.00 ± 0% -33.33% (p=0.000 n=10) PrevEventIDs/Original10-8 1512.0 ± 0% 500.0 ± 0% -66.93% (p=0.000 n=10) PrevEventIDs/Original100-8 11.977Ki ± 0% 7.023Ki ± 0% -41.36% (p=0.000 n=10) PrevEventIDs/Original500-8 67.227Ki ± 0% 7.023Ki ± 0% -89.55% (p=0.000 n=10) PrevEventIDs/Original1000-8 163.227Ki ± 0% 7.023Ki ± 0% -95.70% (p=0.000 n=10) PrevEventIDs/Original2000-8 347.227Ki ± 0% 7.023Ki ± 0% -97.98% (p=0.000 n=10) geomean 12.96Ki 1.954Ki -84.92% │ old.txt │ new.txt │ │ allocs/op │ allocs/op vs base │ PrevEventIDs/Original1-8 2.000 ± 0% 1.000 ± 0% -50.00% (p=0.000 n=10) PrevEventIDs/Original10-8 6.000 ± 0% 2.000 ± 0% -66.67% (p=0.000 n=10) PrevEventIDs/Original100-8 9.000 ± 0% 3.000 ± 0% -66.67% (p=0.000 n=10) PrevEventIDs/Original500-8 12.000 ± 0% 3.000 ± 0% -75.00% (p=0.000 n=10) PrevEventIDs/Original1000-8 14.000 ± 0% 3.000 ± 0% -78.57% (p=0.000 n=10) PrevEventIDs/Original2000-8 16.000 ± 0% 3.000 ± 0% -81.25% (p=0.000 n=10) geomean 8.137 2.335 -71.31% ```
This commit is contained in:
parent
d357615452
commit
8e4dc6b4ae
@ -95,6 +95,12 @@ func Backfill(
|
||||
}
|
||||
}
|
||||
|
||||
// Enforce a limit of 100 events, as not to hit the DB to hard.
|
||||
// Synapse has a hard limit of 100 events as well.
|
||||
if req.Limit > 100 {
|
||||
req.Limit = 100
|
||||
}
|
||||
|
||||
// Query the Roomserver.
|
||||
if err = rsAPI.PerformBackfill(httpReq.Context(), &req, &res); err != nil {
|
||||
util.GetLogger(httpReq.Context()).WithError(err).Error("query.PerformBackfill failed")
|
||||
|
@ -8,7 +8,6 @@ import (
|
||||
"github.com/matrix-org/dendrite/roomserver/types"
|
||||
"github.com/matrix-org/gomatrixserverlib"
|
||||
"github.com/matrix-org/gomatrixserverlib/spec"
|
||||
"github.com/matrix-org/util"
|
||||
)
|
||||
|
||||
type PerformCreateRoomRequest struct {
|
||||
@ -91,14 +90,44 @@ type PerformBackfillRequest struct {
|
||||
VirtualHost spec.ServerName `json:"virtual_host"`
|
||||
}
|
||||
|
||||
// PrevEventIDs returns the prev_event IDs of all backwards extremities, de-duplicated in a lexicographically sorted order.
|
||||
// limitPrevEventIDs is the maximum of eventIDs we
|
||||
// return when calling PrevEventIDs.
|
||||
const limitPrevEventIDs = 100
|
||||
|
||||
// PrevEventIDs returns the prev_event IDs of either 100 backwards extremities or
|
||||
// len(r.BackwardsExtremities). Limited to 100, due to Synapse/Dendrite stopping after reaching
|
||||
// this limit. (which sounds sane)
|
||||
func (r *PerformBackfillRequest) PrevEventIDs() []string {
|
||||
var prevEventIDs []string
|
||||
for _, pes := range r.BackwardsExtremities {
|
||||
prevEventIDs = append(prevEventIDs, pes...)
|
||||
var uniqueIDs map[string]struct{}
|
||||
|
||||
// Create a unique eventID map of either 100 or len(r.BackwardsExtremities).
|
||||
// 100 since Synapse/Dendrite stops after reaching 100 events.
|
||||
if len(r.BackwardsExtremities) > limitPrevEventIDs {
|
||||
uniqueIDs = make(map[string]struct{}, limitPrevEventIDs)
|
||||
} else {
|
||||
uniqueIDs = make(map[string]struct{}, len(r.BackwardsExtremities))
|
||||
}
|
||||
prevEventIDs = util.UniqueStrings(prevEventIDs)
|
||||
return prevEventIDs
|
||||
|
||||
outerLoop:
|
||||
for _, pes := range r.BackwardsExtremities {
|
||||
for _, evID := range pes {
|
||||
uniqueIDs[evID] = struct{}{}
|
||||
// We found enough unique eventIDs.
|
||||
if len(uniqueIDs) >= limitPrevEventIDs {
|
||||
break outerLoop
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// map -> []string
|
||||
result := make([]string, len(uniqueIDs))
|
||||
i := 0
|
||||
for evID := range uniqueIDs {
|
||||
result[i] = evID
|
||||
i++
|
||||
}
|
||||
|
||||
return result
|
||||
}
|
||||
|
||||
// PerformBackfillResponse is a response to PerformBackfill.
|
||||
|
81
roomserver/api/perform_test.go
Normal file
81
roomserver/api/perform_test.go
Normal file
@ -0,0 +1,81 @@
|
||||
package api
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"math/rand"
|
||||
"testing"
|
||||
|
||||
"github.com/stretchr/testify/assert"
|
||||
)
|
||||
|
||||
func BenchmarkPrevEventIDs(b *testing.B) {
|
||||
for _, x := range []int64{1, 10, 100, 500, 1000, 2000} {
|
||||
benchPrevEventIDs(b, int(x))
|
||||
}
|
||||
}
|
||||
|
||||
func benchPrevEventIDs(b *testing.B, count int) {
|
||||
bwExtrems := generateBackwardsExtremities(b, count)
|
||||
backfiller := PerformBackfillRequest{
|
||||
BackwardsExtremities: bwExtrems,
|
||||
}
|
||||
|
||||
b.Run(fmt.Sprintf("Original%d", count), func(b *testing.B) {
|
||||
b.ResetTimer()
|
||||
for i := 0; i < b.N; i++ {
|
||||
prevIDs := backfiller.PrevEventIDs()
|
||||
_ = prevIDs
|
||||
}
|
||||
})
|
||||
}
|
||||
|
||||
type testLike interface {
|
||||
Helper()
|
||||
}
|
||||
|
||||
const randomIDCharsCount = 10
|
||||
|
||||
func generateBackwardsExtremities(t testLike, count int) map[string][]string {
|
||||
t.Helper()
|
||||
result := make(map[string][]string, count)
|
||||
for i := 0; i < count; i++ {
|
||||
eventID := randomEventId(int64(i))
|
||||
result[eventID] = []string{
|
||||
randomEventId(int64(i + 1)),
|
||||
randomEventId(int64(i + 2)),
|
||||
randomEventId(int64(i + 3)),
|
||||
}
|
||||
}
|
||||
return result
|
||||
}
|
||||
|
||||
const alphanumerics = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
|
||||
|
||||
// randomEventId generates a pseudo-random string of length n.
|
||||
func randomEventId(src int64) string {
|
||||
randSrc := rand.NewSource(src)
|
||||
b := make([]byte, randomIDCharsCount)
|
||||
for i := range b {
|
||||
b[i] = alphanumerics[randSrc.Int63()%int64(len(alphanumerics))]
|
||||
}
|
||||
return string(b)
|
||||
}
|
||||
|
||||
func TestPrevEventIDs(t *testing.T) {
|
||||
// generate 10 backwards extremities
|
||||
bwExtrems := generateBackwardsExtremities(t, 10)
|
||||
backfiller := PerformBackfillRequest{
|
||||
BackwardsExtremities: bwExtrems,
|
||||
}
|
||||
|
||||
prevIDs := backfiller.PrevEventIDs()
|
||||
// Given how "generateBackwardsExtremities" works, this
|
||||
// generates 12 unique event IDs
|
||||
assert.Equal(t, 12, len(prevIDs))
|
||||
|
||||
// generate 200 backwards extremities
|
||||
backfiller.BackwardsExtremities = generateBackwardsExtremities(t, 200)
|
||||
prevIDs = backfiller.PrevEventIDs()
|
||||
// PrevEventIDs returns at max 100 event IDs
|
||||
assert.Equal(t, 100, len(prevIDs))
|
||||
}
|
Loading…
Reference in New Issue
Block a user