summaryrefslogtreecommitdiffstats
path: root/vendor/github.com/minio/minio-go/retry.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/github.com/minio/minio-go/retry.go')
-rw-r--r--vendor/github.com/minio/minio-go/retry.go138
1 files changed, 138 insertions, 0 deletions
diff --git a/vendor/github.com/minio/minio-go/retry.go b/vendor/github.com/minio/minio-go/retry.go
new file mode 100644
index 000000000..41b70e474
--- /dev/null
+++ b/vendor/github.com/minio/minio-go/retry.go
@@ -0,0 +1,138 @@
+/*
+ * Minio Go Library for Amazon S3 Compatible Cloud Storage (C) 2015, 2016 Minio, Inc.
+ *
+ * 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 minio
+
+import (
+ "net"
+ "net/http"
+ "net/url"
+ "strings"
+ "time"
+)
+
+// MaxRetry is the maximum number of retries before stopping.
+var MaxRetry = 5
+
+// MaxJitter will randomize over the full exponential backoff time
+const MaxJitter = 1.0
+
+// NoJitter disables the use of jitter for randomizing the exponential backoff time
+const NoJitter = 0.0
+
+// newRetryTimer creates a timer with exponentially increasing delays
+// until the maximum retry attempts are reached.
+func (c Client) newRetryTimer(maxRetry int, unit time.Duration, cap time.Duration, jitter float64, doneCh chan struct{}) <-chan int {
+ attemptCh := make(chan int)
+
+ // computes the exponential backoff duration according to
+ // https://www.awsarchitectureblog.com/2015/03/backoff.html
+ exponentialBackoffWait := func(attempt int) time.Duration {
+ // normalize jitter to the range [0, 1.0]
+ if jitter < NoJitter {
+ jitter = NoJitter
+ }
+ if jitter > MaxJitter {
+ jitter = MaxJitter
+ }
+
+ //sleep = random_between(0, min(cap, base * 2 ** attempt))
+ sleep := unit * time.Duration(1<<uint(attempt))
+ if sleep > cap {
+ sleep = cap
+ }
+ if jitter != NoJitter {
+ sleep -= time.Duration(c.random.Float64() * float64(sleep) * jitter)
+ }
+ return sleep
+ }
+
+ go func() {
+ defer close(attemptCh)
+ for i := 0; i < maxRetry; i++ {
+ select {
+ // Attempts start from 1.
+ case attemptCh <- i + 1:
+ case <-doneCh:
+ // Stop the routine.
+ return
+ }
+ time.Sleep(exponentialBackoffWait(i))
+ }
+ }()
+ return attemptCh
+}
+
+// isNetErrorRetryable - is network error retryable.
+func isNetErrorRetryable(err error) bool {
+ switch err.(type) {
+ case net.Error:
+ switch err.(type) {
+ case *net.DNSError, *net.OpError, net.UnknownNetworkError:
+ return true
+ case *url.Error:
+ // For a URL error, where it replies back "connection closed"
+ // retry again.
+ if strings.Contains(err.Error(), "Connection closed by foreign host") {
+ return true
+ }
+ default:
+ if strings.Contains(err.Error(), "net/http: TLS handshake timeout") {
+ // If error is - tlsHandshakeTimeoutError, retry.
+ return true
+ } else if strings.Contains(err.Error(), "i/o timeout") {
+ // If error is - tcp timeoutError, retry.
+ return true
+ }
+ }
+ }
+ return false
+}
+
+// List of AWS S3 error codes which are retryable.
+var retryableS3Codes = map[string]struct{}{
+ "RequestError": {},
+ "RequestTimeout": {},
+ "Throttling": {},
+ "ThrottlingException": {},
+ "RequestLimitExceeded": {},
+ "RequestThrottled": {},
+ "InternalError": {},
+ "ExpiredToken": {},
+ "ExpiredTokenException": {},
+ // Add more AWS S3 codes here.
+}
+
+// isS3CodeRetryable - is s3 error code retryable.
+func isS3CodeRetryable(s3Code string) (ok bool) {
+ _, ok = retryableS3Codes[s3Code]
+ return ok
+}
+
+// List of HTTP status codes which are retryable.
+var retryableHTTPStatusCodes = map[int]struct{}{
+ 429: {}, // http.StatusTooManyRequests is not part of the Go 1.5 library, yet
+ http.StatusInternalServerError: {},
+ http.StatusBadGateway: {},
+ http.StatusServiceUnavailable: {},
+ // Add more HTTP status codes here.
+}
+
+// isHTTPStatusRetryable - is HTTP error code retryable.
+func isHTTPStatusRetryable(httpStatusCode int) (ok bool) {
+ _, ok = retryableHTTPStatusCodes[httpStatusCode]
+ return ok
+}