documentation

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/utils/TracingContext.java

@@ -153,16 +153,16 @@ public void setListener(Listener listener) {
    * X_MS_CLIENT_REQUEST_ID header of the http operation
    * @param httpOperation AbfsHttpOperation instance to set header into
    *                      connection
-   * @param previousFailure List of failures seen before this API trigger on
-   * same operation from AbfsClient.
+   * @param previousFailure Failure seen before this API trigger on
+   * same operation from AbfsClient. It shall be non-null if it is a retry-iteration.
    */
   public void constructHeader(AbfsHttpOperation httpOperation, String previousFailure) {
     clientRequestId = UUID.randomUUID().toString();
     switch (format) {
     case ALL_ID_FORMAT: // Optional IDs (e.g. streamId) may be empty
       header =
           clientCorrelationID + ":" + clientRequestId + ":" + fileSystemID + ":"
-              + getPrimaryRequestIdForHeader(previousFailure) + ":" + streamID
+              + getPrimaryRequestIdForHeader(previousFailure != null) + ":" + streamID
               + ":" + opType + ":" + retryCount;
       header = addFailureReasons(header, previousFailure);
       break;
@@ -176,15 +176,28 @@ public void constructHeader(AbfsHttpOperation httpOperation, String previousFail
       listener.callTracingHeaderValidator(header, format);
     }
     httpOperation.setRequestProperty(HttpHeaderConfigurations.X_MS_CLIENT_REQUEST_ID, header);
+    /*
+    * In case the primaryRequestId is an empty-string and if it is the first try to
+    * API call (previousFailure shall be null), maintain the last part of clientRequestId's
+    * UUID in primaryRequestIdForRetry. This field shall be used as primaryRequestId part
+    * of the x-ms-client-request-id header in case of retry of the same API-request.
+    * */
     if (primaryRequestId.isEmpty() && previousFailure == null) {
       String[] clientRequestIdParts = clientRequestId.split("-");
       primaryRequestIdForRetry = clientRequestIdParts[
           clientRequestIdParts.length - 1];
     }
   }
 
-  private String getPrimaryRequestIdForHeader(final String previousFailure) {
-    if (!primaryRequestId.isEmpty() || previousFailure == null) {
+  /**
+   * Provide value to be used as primaryRequestId part of x-ms-client-request-id header.
+   * @param isRetry define if it's for a retry case.
+   * @return {@link #primaryRequestIdForRetry}:If the {@link #primaryRequestId}
+   * is an empty-string, and it's a retry iteration.
+   * {@link #primaryRequestId} for other cases.
+   * */
+  private String getPrimaryRequestIdForHeader(final Boolean isRetry) {
+    if (!primaryRequestId.isEmpty() || !isRetry) {
       return primaryRequestId;
     }
     return primaryRequestIdForRetry;