HDFS-12460. Make addErasureCodingPolicy an idempotent operation. Contributed by Sammi Chen

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/ErasureCodingPolicyManager.java

@@ -242,14 +242,15 @@ public final class ErasureCodingPolicyManager {
         policy.getSchema(), policy.getCellSize());
     for (ErasureCodingPolicy p : getPolicies()) {
       if (p.getName().equals(assignedNewName)) {
-        throw new HadoopIllegalArgumentException("The policy name " +
-            assignedNewName + " already exists");
+        LOG.info("The policy name " + assignedNewName + " already exists");
+        return p;
       }
       if (p.getSchema().equals(policy.getSchema()) &&
           p.getCellSize() == policy.getCellSize()) {
-        throw new HadoopIllegalArgumentException("A policy with same schema "
+        LOG.info("A policy with same schema "
             + policy.getSchema().toString() + " and cell size "
             + p.getCellSize() + " already exists");
+        return p;
       }
     }
     policy.setName(assignedNewName);

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestErasureCodingPolicies.java

@@ -718,7 +718,7 @@ public class TestErasureCodingPolicies {
     policyArray  = new ErasureCodingPolicy[]{policy0};
     responses = fs.addErasureCodingPolicies(policyArray);
     assertEquals(1, responses.length);
-    assertFalse(responses[0].isSucceed());
+    assertTrue(responses[0].isSucceed());
 
     // Test add policy successfully
     newPolicy =

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNamenodeRetryCache.java

@@ -436,7 +436,7 @@ public class TestNamenodeRetryCache {
 
     LightWeightCache<CacheEntry, CacheEntry> cacheSet = 
         (LightWeightCache<CacheEntry, CacheEntry>) namesystem.getRetryCache().getCacheSet();
-    assertEquals("Retry cache size is wrong", 26, cacheSet.size());
+    assertEquals("Retry cache size is wrong", 34, cacheSet.size());
     
     Map<CacheEntry, CacheEntry> oldEntries = 
         new HashMap<CacheEntry, CacheEntry>();
@@ -455,7 +455,7 @@ public class TestNamenodeRetryCache {
     assertTrue(namesystem.hasRetryCache());
     cacheSet = (LightWeightCache<CacheEntry, CacheEntry>) namesystem
         .getRetryCache().getCacheSet();
-    assertEquals("Retry cache size is wrong", 26, cacheSet.size());
+    assertEquals("Retry cache size is wrong", 34, cacheSet.size());
     iter = cacheSet.iterator();
     while (iter.hasNext()) {
       CacheEntry entry = iter.next();

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/ha/TestRetryCacheWithHA.java

@@ -166,7 +166,7 @@ public class TestRetryCacheWithHA {
     FSNamesystem fsn0 = cluster.getNamesystem(0);
     LightWeightCache<CacheEntry, CacheEntry> cacheSet = 
         (LightWeightCache<CacheEntry, CacheEntry>) fsn0.getRetryCache().getCacheSet();
-    assertEquals("Retry cache size is wrong", 26, cacheSet.size());
+    assertEquals("Retry cache size is wrong", 34, cacheSet.size());
     
     Map<CacheEntry, CacheEntry> oldEntries = 
         new HashMap<CacheEntry, CacheEntry>();
@@ -187,7 +187,7 @@ public class TestRetryCacheWithHA {
     FSNamesystem fsn1 = cluster.getNamesystem(1);
     cacheSet = (LightWeightCache<CacheEntry, CacheEntry>) fsn1
         .getRetryCache().getCacheSet();
-    assertEquals("Retry cache size is wrong", 26, cacheSet.size());
+    assertEquals("Retry cache size is wrong", 34, cacheSet.size());
     iter = cacheSet.iterator();
     while (iter.hasNext()) {
       CacheEntry entry = iter.next();