SLING-5570 - use exponential backoff in retries
git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1732912 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/main/java/org/apache/sling/testing/teleporter/client/ExponentialBackoffDelay.java b/src/main/java/org/apache/sling/testing/teleporter/client/ExponentialBackoffDelay.java
new file mode 100644
index 0000000..e902842
--- /dev/null
+++ b/src/main/java/org/apache/sling/testing/teleporter/client/ExponentialBackoffDelay.java
@@ -0,0 +1,43 @@
+/*
+ * 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.sling.testing.teleporter.client;
+
+/** Wait with exponential backoff, for retries */
+public class ExponentialBackoffDelay {
+ public static final float INCREASE_RATE = 1.2f;
+ private int currentDelay;
+ private final int endDelay;
+
+ public ExponentialBackoffDelay(int startDelayMsec, int endDelayMsec) {
+ currentDelay = startDelayMsec;
+ endDelay = endDelayMsec;
+ }
+
+ public int getNextDelayMsec() {
+ final int result = currentDelay;
+ currentDelay = Math.min(endDelay, (int)(currentDelay * INCREASE_RATE));
+ return result;
+ }
+
+ public void waitNextDelay() {
+ try {
+ final int toWait = getNextDelayMsec();
+ Thread.sleep(toWait);
+ } catch(InterruptedException ignored) {
+ }
+ }
+}
\ No newline at end of file
diff --git a/src/main/java/org/apache/sling/testing/teleporter/client/TeleporterHttpClient.java b/src/main/java/org/apache/sling/testing/teleporter/client/TeleporterHttpClient.java
index dc176c9..e805e45 100644
--- a/src/main/java/org/apache/sling/testing/teleporter/client/TeleporterHttpClient.java
+++ b/src/main/java/org/apache/sling/testing/teleporter/client/TeleporterHttpClient.java
@@ -69,6 +69,7 @@
public void waitForStatus(String url, int expectedStatus, int timeoutMsec) throws IOException {
final long end = System.currentTimeMillis() + timeoutMsec;
final Set<Integer> statusSet = new HashSet<Integer>();
+ final ExponentialBackoffDelay d = new ExponentialBackoffDelay(50, 250);
while(System.currentTimeMillis() < end) {
try {
final int status = getHttpGetStatus(url);
@@ -76,7 +77,7 @@
if(status == expectedStatus) {
return;
}
- Thread.sleep(50);
+ d.waitNextDelay();
} catch(Exception ignore) {
}
}
@@ -147,6 +148,7 @@
// Wait for non-404 response that signals that test bundle is ready
final long timeout = System.currentTimeMillis() + (testReadyTimeoutSeconds * 1000L);
+ final ExponentialBackoffDelay delay = new ExponentialBackoffDelay(25, 1000);
while(true) {
if(getHttpGetStatus(testUrl) == 200) {
break;
@@ -155,6 +157,7 @@
fail("Timeout waiting for test at " + testUrl + " (" + testReadyTimeoutSeconds + " seconds)");
break;
}
+ delay.waitNextDelay();
}
final HttpURLConnection c = (HttpURLConnection)new URL(testUrl).openConnection();
diff --git a/src/test/java/org/apache/sling/testing/teleporter/client/ExponentialBackoffDelayTest.java b/src/test/java/org/apache/sling/testing/teleporter/client/ExponentialBackoffDelayTest.java
new file mode 100644
index 0000000..acec7f9
--- /dev/null
+++ b/src/test/java/org/apache/sling/testing/teleporter/client/ExponentialBackoffDelayTest.java
@@ -0,0 +1,45 @@
+/*
+ * 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.sling.testing.teleporter.client;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class ExponentialBackoffDelayTest {
+ @Test
+ public void testDelaySequence() {
+ final ExponentialBackoffDelay d = new ExponentialBackoffDelay(25, 100);
+ final int [] expected = {
+ 25,
+ 30,
+ 36,
+ 43,
+ 51,
+ 61,
+ 73,
+ 87,
+ 100,
+ 100,
+ 100
+ };
+
+ for(int exp : expected) {
+ assertEquals(exp, d.getNextDelayMsec());
+ }
+ }
+}
\ No newline at end of file
