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Refactor robust retry in http client

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This commit is contained in:
Ben Sarmiento
2024-01-22 19:41:29 +01:00
parent 3131e3cbdf
commit 8aa1362df2
2 changed files with 52 additions and 55 deletions
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105
pkg/http/client.go
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@@ -22,15 +22,11 @@ import (
cmap "github.com/orcaman/concurrent-map/v2"
)
const (
RATE_LIMIT_FACTOR = 4 // should always be > 1
)
type HTTPClient struct {
client *http.Client
maxRetries int
backoff func(attempt int) time.Duration
getRetryIncr func(resp *http.Response, hasRangeHeader bool, err error) int
getRetryIncr func(resp *http.Response, reqHasRangeHeader bool, err error) int
bearerToken string
ensureIPv6Host bool
cfg config.ConfigInterface
@@ -44,12 +40,12 @@ type HTTPClient struct {
// "error_code": 35
// }
type ErrorResponse struct {
type ApiErrorResponse struct {
Message string `json:"error"`
Code int `json:"error_code"`
}
func (e *ErrorResponse) Error() string {
func (e *ApiErrorResponse) Error() string {
return fmt.Sprintf("api response error: %s (code: %d)", e.Message, e.Code)
}
@@ -59,7 +55,7 @@ func NewHTTPClient(token string, maxRetries int, timeoutSecs int, ensureIPv6Host
client: &http.Client{
Timeout: time.Duration(timeoutSecs) * time.Second,
},
maxRetries: maxRetries * RATE_LIMIT_FACTOR,
maxRetries: maxRetries,
backoff: func(attempt int) time.Duration {
maxDuration := 60
backoff := int(math.Pow(2, float64(attempt)))
@@ -68,44 +64,45 @@ func NewHTTPClient(token string, maxRetries int, timeoutSecs int, ensureIPv6Host
}
return time.Duration(backoff) * time.Second
},
getRetryIncr: func(resp *http.Response, hasRangeHeader bool, err error) int {
if resp != nil {
if resp.StatusCode == 429 {
return 1
}
if resp.StatusCode == http.StatusOK && hasRangeHeader {
return 1
}
return 0 // don't retry
} else if err != nil {
log.Errorf("Client request error: %s", err.Error())
if strings.Contains(err.Error(), "api response error") {
if apiErr, ok := err.(*ErrorResponse); ok {
switch apiErr.Code {
case -1: // Internal error
return 1
case 5: // Slow down
return 1
case 6: // Ressource unreachable
return 1
case 17: // Hoster in maintenance
return 1
case 19: // Hoster temporarily unavailable
return 1
case 25: // Service unavailable
return 1
case 34: // Too many requests
return 1
case 36: // Fair Usage Limit
return 1
default:
return 0 // don't retry
}
getRetryIncr: func(resp *http.Response, reqHasRangeHeader bool, err error) int {
if err != nil && strings.HasPrefix(err.Error(), "api response error:") {
if apiErr, ok := err.(*ApiErrorResponse); ok {
switch apiErr.Code {
case -1: // Internal error
return 1
case 5: // Slow down (retry infinitely)
time.Sleep(time.Duration(cfg.GetRateLimitSleepSeconds()) * time.Second)
return -1
case 6: // Ressource unreachable
return 1
case 17: // Hoster in maintenance
return 1
case 19: // Hoster temporarily unavailable
return 1
case 25: // Service unavailable
return 1
case 34: // Too many requests (retry infinitely)
time.Sleep(time.Duration(cfg.GetRateLimitSleepSeconds()) * time.Second)
return -1
case 36: // Fair Usage Limit
return 1
default:
return 0 // don't retry
}
}
return 1
}
return RATE_LIMIT_FACTOR
if resp != nil {
if resp.StatusCode == 429 {
time.Sleep(time.Duration(cfg.GetRateLimitSleepSeconds()) * time.Second)
return -1
}
if resp.Header.Get("Content-Range") == "" && reqHasRangeHeader {
time.Sleep(10 * time.Millisecond)
return -1
}
return 0 // don't retry
}
return 1
},
ensureIPv6Host: ensureIPv6Host,
cfg: cfg,
@@ -177,7 +174,7 @@ func (r *HTTPClient) Do(req *http.Request) (*http.Response, error) {
}
r.replaceHostIfNeeded(req)
// check if Range header is set
hasRangeHeader := req.Header.Get("Range") != "" && req.Header.Get("Range") != "bytes=0-"
reqHasRangeHeader := req.Header.Get("Range") != "" && req.Header.Get("Range") != "bytes=0-"
var resp *http.Response
var err error
@@ -187,7 +184,7 @@ func (r *HTTPClient) Do(req *http.Request) (*http.Response, error) {
if resp != nil && (resp.StatusCode < http.StatusOK || resp.StatusCode > http.StatusPartialContent) {
body, _ := io.ReadAll(resp.Body)
if body != nil {
var errResp ErrorResponse
var errResp ApiErrorResponse
jsonErr := json.Unmarshal(body, &errResp)
if jsonErr == nil {
errResp.Message += fmt.Sprintf(" (status code: %d)", resp.StatusCode)
@@ -195,23 +192,23 @@ func (r *HTTPClient) Do(req *http.Request) (*http.Response, error) {
}
}
}
if incr := r.getRetryIncr(resp, hasRangeHeader, err); incr > 0 {
incr := r.getRetryIncr(resp, reqHasRangeHeader, err)
if resp != nil {
resp.Body.Close()
}
if incr > 0 {
attempt += incr
if attempt > r.maxRetries {
break
}
if incr >= RATE_LIMIT_FACTOR {
if incr > 0 {
time.Sleep(r.backoff(attempt))
} else {
time.Sleep(time.Duration(r.cfg.GetRateLimitSleepSeconds()) * time.Second) // extra delay
}
if resp != nil {
resp.Body.Close()
}
} else {
// if incr == 0, don't retry anymore
} else if incr == 0 {
// don't retry anymore
break
}
// if incr < 0, retry infinitely
}
return resp, err
}