Files
seaweedfs/weed/operation/upload_content_test.go
T
Chris Lu 4bf27278fa topology: fail replica writes fast when a replica is unreachable (#9744)
* operation: bound upload retries and honor context cancellation

retriedUploadData hardcoded 3 attempts and an uninterruptible backoff
sleep. A synchronous replica write to a dead host therefore paid the
full dial timeout three times over before failing.

Add UploadOption.MaxAttempts (<=0 keeps the default of 3) so callers can
cap attempts, and make the loop return as soon as the context is
cancelled so an abandoned upload unwinds instead of retrying.

* topology: fail replica writes fast when a replica is unreachable

DistributedOperation already returns on the first error, but a single
dead replica is itself the slow result: its goroutine retries the upload
three times through the dial timeout (~30s) before any error surfaces,
stalling the originating client write the whole time.

Make the replica write a single attempt (MaxAttempts=1) so a dead
replica fails after one dial timeout instead of three, and thread a
context into DistributedOperation that is cancelled once the outcome is
decided, so a healthy replica is no longer held hostage by one stalled
in a dial. The originating client write is what retries.

* topology: keep replica deletes off the client request context

ReplicatedDelete runs after the local needle is already deleted. Driving
the replica deletes off r.Context() means a client disconnect cancels
them and orphans needles on the replicas, so use a background context.

* operation, topology: trim comments on the replica fail-fast path
2026-05-30 10:45:02 -07:00

300 lines
9.4 KiB
Go

package operation
import (
"bytes"
"context"
"errors"
"fmt"
"io"
"net/http"
"strings"
"sync"
"testing"
"time"
"github.com/seaweedfs/seaweedfs/weed/security"
)
type scriptedHTTPResponse struct {
status int
body string
}
type scriptedHTTPClient struct {
mu sync.Mutex
responses map[string][]scriptedHTTPResponse
calls []string
}
func testIsUploadRetryableAssignError(err error) bool {
if err == nil {
return false
}
for _, retryable := range uploadRetryableAssignErrList {
if strings.Contains(err.Error(), retryable) {
return true
}
}
return false
}
func (c *scriptedHTTPClient) Do(req *http.Request) (*http.Response, error) {
c.mu.Lock()
defer c.mu.Unlock()
url := req.URL.String()
c.calls = append(c.calls, url)
plans := c.responses[url]
if len(plans) == 0 {
return nil, fmt.Errorf("unexpected request to %s", url)
}
plan := plans[0]
c.responses[url] = plans[1:]
return &http.Response{
StatusCode: plan.status,
Header: make(http.Header),
Body: io.NopCloser(strings.NewReader(plan.body)),
}, nil
}
func TestIsUploadRetryableAssignError(t *testing.T) {
testCases := []struct {
name string
err error
want bool
}{
{name: "nil", err: nil, want: false},
{name: "transport", err: fmt.Errorf("transport is closing"), want: true},
{name: "read only", err: fmt.Errorf("volume 1 is read only"), want: true},
{name: "volume full", err: fmt.Errorf("failed to write to local disk: append to volume 1 size 0 actualSize 0: Volume Size 33555976 Exceeded 33554432"), want: true},
{name: "other permanent", err: fmt.Errorf("mismatching cookie"), want: false},
}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
if got := testIsUploadRetryableAssignError(tc.err); got != tc.want {
t.Fatalf("testIsUploadRetryableAssignError(%v) = %v, want %v", tc.err, got, tc.want)
}
})
}
}
func TestUploadWithRetryDataReassignsOnVolumeSizeExceeded(t *testing.T) {
httpClient := &scriptedHTTPClient{
responses: map[string][]scriptedHTTPResponse{
"http://volume-a/1,first": {
{status: http.StatusInternalServerError, body: `{"error":"failed to write to local disk: append to volume 1 size 0 actualSize 0: Volume Size 33555976 Exceeded 33554432"}`},
{status: http.StatusInternalServerError, body: `{"error":"failed to write to local disk: append to volume 1 size 0 actualSize 0: Volume Size 33555976 Exceeded 33554432"}`},
{status: http.StatusInternalServerError, body: `{"error":"failed to write to local disk: append to volume 1 size 0 actualSize 0: Volume Size 33555976 Exceeded 33554432"}`},
},
"http://volume-b/2,second": {
{status: http.StatusCreated, body: `{"name":"test.bin","size":3}`},
},
},
}
uploader := newUploader(httpClient)
assignCalls := 0
fileID, uploadResult, err := uploader.uploadWithRetryData(func() (string, string, security.EncodedJwt, error) {
assignCalls++
if assignCalls == 1 {
return "1,first", "volume-a", "", nil
}
return "2,second", "volume-b", "", nil
}, &UploadOption{Filename: "test.bin"}, func(host, fileId string) string {
return "http://" + host + "/" + fileId
}, []byte("abc"))
if err != nil {
t.Fatalf("expected success after reassignment, got %v", err)
}
if fileID != "2,second" {
t.Fatalf("expected second file id, got %s", fileID)
}
if assignCalls != 2 {
t.Fatalf("expected 2 assign attempts, got %d", assignCalls)
}
if uploadResult == nil || uploadResult.Name != "test.bin" {
t.Fatalf("expected successful upload result, got %#v", uploadResult)
}
if len(httpClient.calls) != 4 {
t.Fatalf("expected 4 upload attempts (3 same-url retries + 1 reassigned upload), got %d", len(httpClient.calls))
}
if httpClient.calls[0] != "http://volume-a/1,first" || httpClient.calls[3] != "http://volume-b/2,second" {
t.Fatalf("unexpected upload call sequence: %#v", httpClient.calls)
}
}
// bodyCapturingHTTPClient drains req.Body on every Do, optionally failing the
// first attempt with a transport error so we can verify upload_content rewinds
// the body before retrying.
type bodyCapturingHTTPClient struct {
mu sync.Mutex
bodies [][]byte
failFirst string
successJSON string
}
func (c *bodyCapturingHTTPClient) Do(req *http.Request) (*http.Response, error) {
c.mu.Lock()
defer c.mu.Unlock()
var captured []byte
if req.Body != nil {
b, err := io.ReadAll(req.Body)
if err != nil {
return nil, err
}
captured = b
}
c.bodies = append(c.bodies, captured)
if len(c.bodies) == 1 && c.failFirst != "" {
return nil, errors.New(c.failFirst)
}
return &http.Response{
StatusCode: http.StatusCreated,
Header: make(http.Header),
Body: io.NopCloser(strings.NewReader(c.successJSON)),
}, nil
}
// TestUploadRewindsBodyOnConnectionReset reproduces issue #9139 follow-up:
// when the inner Do retry fires on a "connection reset" / "closed network"
// error, the *bytes.Reader body has already been consumed, so without an
// explicit rewind the second attempt sends 0 bytes and Go's transport surfaces
// "ContentLength=N with Body length 0".
func TestUploadRewindsBodyOnConnectionReset(t *testing.T) {
for _, transient := range []string{
"connection reset by peer",
"use of closed network connection",
} {
t.Run(transient, func(t *testing.T) {
client := &bodyCapturingHTTPClient{
failFirst: transient,
successJSON: `{"name":"test.bin","size":42}`,
}
uploader := newUploader(client)
payload := bytes.Repeat([]byte("payload-"), 256) // 2048 bytes
_, err := uploader.UploadData(context.Background(), payload, &UploadOption{
UploadUrl: "http://volume/1,abc",
Filename: "test.bin",
})
if err != nil {
t.Fatalf("upload should succeed after inner retry, got %v", err)
}
if len(client.bodies) != 2 {
t.Fatalf("expected 2 Do attempts, got %d", len(client.bodies))
}
if len(client.bodies[0]) == 0 {
t.Fatalf("first attempt sent an empty body; test setup wrong")
}
if !bytes.Equal(client.bodies[0], client.bodies[1]) {
t.Fatalf("retry body length=%d differs from first attempt length=%d (body was not rewound)",
len(client.bodies[1]), len(client.bodies[0]))
}
})
}
}
// deadReplicaClient simulates an unreachable replica: every request blocks for
// dialDelay (standing in for the TCP dial timeout) and then fails, unless the
// request context is cancelled first.
type deadReplicaClient struct {
mu sync.Mutex
calls int
dialDelay time.Duration
}
func (c *deadReplicaClient) attempts() int {
c.mu.Lock()
defer c.mu.Unlock()
return c.calls
}
func (c *deadReplicaClient) Do(req *http.Request) (*http.Response, error) {
c.mu.Lock()
c.calls++
c.mu.Unlock()
select {
case <-time.After(c.dialDelay):
return nil, fmt.Errorf("dial tcp %s: i/o timeout", req.URL.Host)
case <-req.Context().Done():
return nil, req.Context().Err()
}
}
// TestUploadToDeadReplicaRetriesThreeTimes reproduces the dead-replica upload
// stall: a synchronous replica write to an unreachable host pays the dial
// timeout three times over, so one dead replica stalls the caller for ~3x the
// dial timeout. In production dialDelay is the 10s dialer timeout, so the
// caller blocks ~30s before the failure surfaces.
func TestUploadToDeadReplicaRetriesThreeTimes(t *testing.T) {
client := &deadReplicaClient{dialDelay: 100 * time.Millisecond}
uploader := newUploader(client)
start := time.Now()
_, err := uploader.UploadData(context.Background(), []byte("hello"), &UploadOption{
UploadUrl: "http://dead-replica:8080/3,01",
Filename: "test.bin",
})
elapsed := time.Since(start)
if err == nil {
t.Fatal("expected an error uploading to a dead replica")
}
if got := client.attempts(); got != 3 {
t.Fatalf("dial attempts = %d, want 3 (each attempt pays the full dial timeout)", got)
}
t.Logf("dead replica stalled the caller for %v across %d attempts", elapsed, client.attempts())
}
// TestUploadToDeadReplicaSingleAttempt verifies the fix: a synchronous replica
// write makes a single attempt (MaxAttempts=1), so a dead replica fails after
// one dial timeout instead of three. The outer client write still retries.
func TestUploadToDeadReplicaSingleAttempt(t *testing.T) {
client := &deadReplicaClient{dialDelay: 100 * time.Millisecond}
uploader := newUploader(client)
_, err := uploader.UploadData(context.Background(), []byte("hello"), &UploadOption{
UploadUrl: "http://dead-replica:8080/3,01",
Filename: "test.bin",
MaxAttempts: 1,
})
if err == nil {
t.Fatal("expected an error uploading to a dead replica")
}
if got := client.attempts(); got != 1 {
t.Fatalf("dial attempts = %d, want 1", got)
}
}
// TestUploadRetryStopsOnContextCancel verifies the retry loop honors context
// cancellation so DistributedOperation can abandon a slow replica once the
// write outcome is already decided by another replica.
func TestUploadRetryStopsOnContextCancel(t *testing.T) {
client := &deadReplicaClient{dialDelay: time.Hour} // would block ~forever per attempt
uploader := newUploader(client)
ctx, cancel := context.WithCancel(context.Background())
cancel() // already decided elsewhere
start := time.Now()
_, err := uploader.UploadData(ctx, []byte("hello"), &UploadOption{
UploadUrl: "http://dead-replica:8080/3,01",
Filename: "test.bin",
})
if err == nil {
t.Fatal("expected a context error")
}
if elapsed := time.Since(start); elapsed > 10*time.Second {
t.Fatalf("upload did not abort on cancellation: took %v", elapsed)
}
if got := client.attempts(); got > 1 {
t.Fatalf("dial attempts = %d, want at most 1 after cancellation", got)
}
}