philipnee commented on a change in pull request #11797:
URL: https://github.com/apache/kafka/pull/11797#discussion_r819898973



##########
File path: 
connect/runtime/src/main/java/org/apache/kafka/connect/util/RetryUtil.java
##########
@@ -0,0 +1,107 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 org.apache.kafka.connect.util;
+
+import org.apache.kafka.common.errors.RetriableException;
+import org.apache.kafka.common.errors.WakeupException;
+import org.apache.kafka.common.utils.Utils;
+import org.apache.kafka.connect.errors.ConnectException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.time.Duration;
+import java.util.Optional;
+import java.util.concurrent.Callable;
+import java.util.function.Supplier;
+
+public class RetryUtil {
+    private static final Logger log = LoggerFactory.getLogger(RetryUtil.class);
+
+    /**
+     * The method executes the callable at least once, optionally retrying the 
callable if
+     * {@link org.apache.kafka.connect.errors.RetriableException} is being 
thrown.  If timeout is exhausted,
+     * then the last exception is wrapped with a {@link 
org.apache.kafka.connect.errors.ConnectException} and thrown.
+     *
+     * <p>{@code description} supplies the message that indicates the purpose 
of the callable since the message will
+     * be used for logging.  For example, "list offsets". If the supplier is 
null or the supplied string is
+     * null, {@code callable} will be used as the default string.
+     *
+     * <p>The task will be executed at least once. No retries will be 
performed 
+     * if {@code timeoutDuration} is 0 or negative, or if {@code 
timeoutDuration} is less than {@code retryBackoffMs}.
+     *
+     * <p>A {@code retryBackoffMs} that is negative or zero will result in no 
delays between retries.
+     *
+     * @param callable          the function to execute
+     * @param description       supplier that provides custom message for 
logging purpose
+     * @param timeoutDuration   timeout duration; must not be null
+     * @param retryBackoffMs    the number of milliseconds to delay upon 
receiving a
+     *                          {@link 
org.apache.kafka.connect.errors.RetriableException} before retrying again
+     * @throws ConnectException If the task exhausted all the retries
+     */
+    public static <T> T retryUntilTimeout(Callable<T> callable, 
Supplier<String> description, Duration timeoutDuration, long retryBackoffMs) 
throws Exception {
+        // if null supplier or string is provided, the message will be default 
to "callabe"
+        String descriptionStr = Optional.ofNullable(description)
+                .map(Supplier::get)
+                .orElse("callable");
+
+        // handling null duration
+        long timeoutMs = Optional.ofNullable(timeoutDuration)
+                .map(Duration::toMillis)
+                .orElse(0L);
+
+        if (retryBackoffMs >= timeoutMs) {
+            log.debug("Executing {} only once, since retryBackoffMs={} is 
larger than total timeoutMs={}",
+                    descriptionStr, retryBackoffMs, timeoutMs);
+        }
+
+        if (retryBackoffMs < 0) {
+            log.debug("Invalid retryBackoffMs, must be non-negative but got 
{}. 0 will be used instead",
+                    retryBackoffMs);
+            retryBackoffMs = 0;
+        }
+
+        if (timeoutMs <= 0 || retryBackoffMs >= timeoutMs) {
+            // no retry
+            return callable.call();
+        }
+
+        long end = System.currentTimeMillis() + timeoutMs;
+        int attempt = 0;
+        Throwable lastError = null;
+        while (System.currentTimeMillis() <= end) {

Review comment:
       I see - I should then keep the line 77 to handle special cases.




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