Make NodeAvailabilityCache TTL configurable, increase default from 50 to 1000 millis.

Martin Grotzke · Martin Grotzke · commit 73763b494451 · 2013-12-02T14:44:59.000+01:00
The TTL defines, how long the availability (or inavailability) of a given memcached
node is cached (considered to be correct). If a request comes in after the TTL has
passed msm will "ping" the related memcached node to see if it's yet available (or
available again).
diff --git a/core/src/main/java/de/javakaffee/web/msm/Configurations.java b/core/src/main/java/de/javakaffee/web/msm/Configurations.java
@@ -0,0 +1,45 @@
+/*
+ * Copyright 2013 Martin Grotzke
+ *
+ * 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
+ *
+ *     https://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 &quot;AS IS&quot; 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 de.javakaffee.web.msm;
+
+import org.apache.juli.logging.Log;
+import org.apache.juli.logging.LogFactory;
+
+/**
+ * Configuration keys and helper functions.
+ *
+ * @author @author <a href="mailto:martin.grotzke@javakaffee.de">Martin Grotzke</a>
+ */
+public final class Configurations {
+
+    public static final String NODE_AVAILABILITY_CACHE_TTL_KEY = "msm.nodeAvailabilityCacheTTL";
+
+    private static final Log LOG = LogFactory.getLog(Configurations.class);
+
+    public static int getSystemPropertyInt(final String propName, final int defaultValue) {
+        final String value = System.getProperty(propName);
+        if(value != null) {
+            try {
+                return Integer.parseInt(value);
+            } catch(final NumberFormatException e) {
+                LOG.warn("Could not parse configured value for system property '" + propName + "': " + value);
+            }
+        }
+        return defaultValue;
+    }
+
+}
diff --git a/core/src/main/java/de/javakaffee/web/msm/MemcachedNodesManager.java b/core/src/main/java/de/javakaffee/web/msm/MemcachedNodesManager.java
@@ -15,6 +15,9 @@
  */
 package de.javakaffee.web.msm;
 
+import static de.javakaffee.web.msm.Configurations.NODE_AVAILABILITY_CACHE_TTL_KEY;
+import static de.javakaffee.web.msm.Configurations.getSystemPropertyInt;
+
 import java.net.InetSocketAddress;
 import java.net.URI;
 import java.net.URISyntaxException;
@@ -70,7 +73,7 @@ public static interface MemcachedClientCallback {
     private static final String COUCHBASE_BUCKET_NODES_REGEX = COUCHBASE_BUCKET_NODE_REGEX + "(?:(?:\\s+|,)" + COUCHBASE_BUCKET_NODE_REGEX + ")*";
     private static final Pattern COUCHBASE_BUCKET_NODES_PATTERN = Pattern.compile( COUCHBASE_BUCKET_NODES_REGEX );
 
-    private static final int NODE_AVAILABILITY_CACHE_TTL = 50;
+    private static final int NODE_AVAILABILITY_CACHE_TTL = getSystemPropertyInt(NODE_AVAILABILITY_CACHE_TTL_KEY, 1000);
 
 	private final String _memcachedNodes;
     private final NodeIdList _primaryNodeIds;
diff --git a/core/src/test/java/de/javakaffee/web/msm/integration/TestUtils.java b/core/src/test/java/de/javakaffee/web/msm/integration/TestUtils.java
@@ -16,6 +16,7 @@
  */
 package de.javakaffee.web.msm.integration;
 
+import static de.javakaffee.web.msm.Configurations.NODE_AVAILABILITY_CACHE_TTL_KEY;
 import static de.javakaffee.web.msm.integration.TestUtils.Predicates.elementAt;
 import static de.javakaffee.web.msm.integration.TestUtils.Predicates.notNull;
 import static org.testng.Assert.assertEquals;
@@ -121,6 +122,7 @@ public abstract class TestUtils {
 
     static {
         initLogConfig(TestUtils.class);
+        System.setProperty(NODE_AVAILABILITY_CACHE_TTL_KEY, "50");
     }
 
     private static void initLogConfig(final Class<? extends TestUtils> clazz) {
