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Cache failed handle resolutions with exponentially increasing TTLs (#300)
authored by
Whyrusleeping
and committed by
GitHub
e4f0da26
f934d626
+62
-4
+54
-2
api/extra.go
+54
-2
api/extra.go
···
14
14
15
15
"github.com/bluesky-social/indigo/did"
16
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"github.com/bluesky-social/indigo/xrpc"
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+
arc "github.com/hashicorp/golang-lru/arc/v2"
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logging "github.com/ipfs/go-log"
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"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
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otel "go.opentelemetry.io/otel"
···
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ResolveHandleToDid(ctx context.Context, handle string) (string, error)
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}
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+
type failCacheItem struct {
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+
err error
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+
count int
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+
expiresAt time.Time
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+
}
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+
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type ProdHandleResolver struct {
79
-
ReqMod func(*http.Request, string) error
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+
ReqMod func(*http.Request, string) error
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+
FailCache *arc.ARCCache[string, *failCacheItem]
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+
}
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+
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+
func NewProdHandleResolver(failureCacheSize int) (*ProdHandleResolver, error) {
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+
failureCache, err := arc.NewARC[string, *failCacheItem](failureCacheSize)
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+
if err != nil {
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+
return nil, err
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+
}
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+
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return &ProdHandleResolver{
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FailCache: failureCache,
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}, nil
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}
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func (dr *ProdHandleResolver) ResolveHandleToDid(ctx context.Context, handle string) (string, error) {
···
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ctx, span := otel.Tracer("resolver").Start(ctx, "ResolveHandleToDid")
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defer span.End()
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+
var cachedFailureCount int
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+
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+
if dr.FailCache != nil {
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+
if item, ok := dr.FailCache.Get(handle); ok {
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+
cachedFailureCount = item.count
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+
if item.expiresAt.After(time.Now()) {
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+
return "", item.err
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+
}
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+
dr.FailCache.Remove(handle)
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+
}
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}
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+
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var wkres, dnsres string
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var wkerr, dnserr error
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···
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return wkres, nil
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}
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-
return "", errors.Join(fmt.Errorf("no did record found for handle %q", handle), dnserr, wkerr)
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+
err := errors.Join(fmt.Errorf("no did record found for handle %q", handle), dnserr, wkerr)
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+
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if dr.FailCache != nil {
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cachedFailureCount++
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+
expireAt := time.Now().Add(time.Millisecond * 100)
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+
if cachedFailureCount > 1 {
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+
// exponential backoff
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+
expireAt = time.Now().Add(time.Millisecond * 100 * time.Duration(cachedFailureCount*cachedFailureCount))
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+
// Clamp to one hour
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+
if expireAt.After(time.Now().Add(time.Hour)) {
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expireAt = time.Now().Add(time.Hour)
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+
}
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+
}
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+
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+
dr.FailCache.Add(handle, &failCacheItem{
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+
err: err,
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+
expiresAt: expireAt,
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+
count: cachedFailureCount,
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+
})
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+
}
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+
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+
return "", err
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}
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func (dr *ProdHandleResolver) resolveWellKnown(ctx context.Context, handle string) (string, error) {
+5
-2
cmd/bigsky/main.go
+5
-2
cmd/bigsky/main.go
···
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297
blobstore = &blobs.DiskBlobStore{bsdir}
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}
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-
prodHR := api.ProdHandleResolver{}
300
+
prodHR, err := api.NewProdHandleResolver(100_000)
301
+
if err != nil {
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+
return fmt.Errorf("failed to set up handle resolver: %w", err)
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+
}
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if rlskip != "" {
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prodHR.ReqMod = func(req *http.Request, host string) error {
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if strings.HasSuffix(host, ".bsky.social") {
···
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}
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}
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-
var hr api.HandleResolver = &prodHR
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+
var hr api.HandleResolver = prodHR
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if cctx.StringSlice("handle-resolver-hosts") != nil {
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hr = &api.TestHandleResolver{
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TrialHosts: cctx.StringSlice("handle-resolver-hosts"),
+1
go.mod
+1
go.mod
···
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12
github.com/gorilla/websocket v1.5.0
13
13
github.com/hashicorp/go-retryablehttp v0.7.2
14
14
github.com/hashicorp/golang-lru v0.5.4
15
+
github.com/hashicorp/golang-lru/arc/v2 v2.0.6
15
16
github.com/hashicorp/golang-lru/v2 v2.0.6
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github.com/icrowley/fake v0.0.0-20221112152111-d7b7e2276db2
17
18
github.com/ipfs/go-block-format v0.1.2
+2
go.sum
+2
go.sum
···
235
235
github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
236
236
github.com/hashicorp/golang-lru v0.5.4 h1:YDjusn29QI/Das2iO9M0BHnIbxPeyuCHsjMW+lJfyTc=
237
237
github.com/hashicorp/golang-lru v0.5.4/go.mod h1:iADmTwqILo4mZ8BN3D2Q6+9jd8WM5uGBxy+E8yxSoD4=
238
+
github.com/hashicorp/golang-lru/arc/v2 v2.0.6 h1:4NU7uP5vSoK6TbaMj3NtY478TTAWLso/vL1gpNrInHg=
239
+
github.com/hashicorp/golang-lru/arc/v2 v2.0.6/go.mod h1:cfdDIX05DWvYV6/shsxDfa/OVcRieOt+q4FnM8x+Xno=
238
240
github.com/hashicorp/golang-lru/v2 v2.0.6 h1:3xi/Cafd1NaoEnS/yDssIiuVeDVywU0QdFGl3aQaQHM=
239
241
github.com/hashicorp/golang-lru/v2 v2.0.6/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyfM2/ZepoAG6RGpeM=
240
242
github.com/huin/goupnp v1.0.3 h1:N8No57ls+MnjlB+JPiCVSOyy/ot7MJTqlo7rn+NYSqQ=