HBASE-5058 Allow HBaseAmin to use an existing connection (Lars H)

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1220989 13f79535-47bb-0310-9956-ffa450edef68

src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java

@@ -95,7 +95,7 @@ public class HBaseAdmin implements Abortable, Closeable {
   public HBaseAdmin(Configuration c)
   throws MasterNotRunningException, ZooKeeperConnectionException {
     this.conf = HBaseConfiguration.create(c);
-      this.connection = HConnectionManager.getConnection(this.conf);
+    this.connection = HConnectionManager.getConnection(this.conf);
     this.pause = this.conf.getLong("hbase.client.pause", 1000);
     this.numRetries = this.conf.getInt("hbase.client.retries.number", 10);
     this.retryLongerMultiplier = this.conf.getInt(
@@ -111,9 +111,6 @@ public class HBaseAdmin implements Abortable, Closeable {
       } catch (MasterNotRunningException mnre) {
         HConnectionManager.deleteStaleConnection(this.connection);
         this.connection = HConnectionManager.getConnection(this.conf);
-      } catch (UndeclaredThrowableException ute) {
-        HConnectionManager.deleteStaleConnection(this.connection);
-        this.connection = HConnectionManager.getConnection(this.conf);
       }
 
       tries++;
@@ -135,6 +132,29 @@ public class HBaseAdmin implements Abortable, Closeable {
     }
   }
 
+ /**
+   * Constructor for externally managed HConnections.
+   * This constructor fails fast if the HMaster is not running.
+   * The HConnection can be re-used again in another attempt.
+   * This constructor fails fast.
+   *
+   * @param connection The HConnection instance to use
+   * @throws MasterNotRunningException if the master is not running
+   * @throws ZooKeeperConnectionException if unable to connect to zookeeper
+   */
+  public HBaseAdmin(HConnection connection)
+      throws MasterNotRunningException, ZooKeeperConnectionException {
+    this.conf = connection.getConfiguration();
+    this.connection = connection;
+
+    this.pause = this.conf.getLong("hbase.client.pause", 1000);
+    this.numRetries = this.conf.getInt("hbase.client.retries.number", 10);
+    this.retryLongerMultiplier = this.conf.getInt(
+        "hbase.client.retries.longer.multiplier", 10);
+
+    this.connection.getMaster();
+  }
+
   /**
    * @return A new CatalogTracker instance; call {@link #cleanupCatalogTracker(CatalogTracker)}
    * to cleanup the returned catalog tracker.

src/main/java/org/apache/hadoop/hbase/client/HConnectionManager.java

@@ -623,14 +623,20 @@ public class HConnectionManager {
     throws MasterNotRunningException, ZooKeeperConnectionException {
 
       // Check if we already have a good master connection
-      if (master != null) {
+      try {
-        if (master.isMasterRunning()) {
+        if (master != null && master.isMasterRunning()) {
           return master;
         }
+      } catch (UndeclaredThrowableException ute) {
+        // log, but ignore, the loop below will attempt to reconnect
+        LOG.info("Exception contacting master. Retrying...", ute.getCause());
       }
+
       checkIfBaseNodeAvailable();
       ServerName sn = null;
       synchronized (this.masterLock) {
+        this.master = null;
+
         for (int tries = 0;
           !this.closed &&
           !this.masterChecked && this.master == null &&
@@ -679,15 +685,19 @@ public class HConnectionManager {
             throw new RuntimeException("Thread was interrupted while trying to connect to master.");
           }
         }
-        this.masterChecked = true;
+        // Avoid re-checking in the future if this is a managed HConnection,
-      }
+        // even if we failed to acquire a master.
-      if (this.master == null) {
+        // (this is to retain the existing behavior before HBASE-5058)
-        if (sn == null) {
+        this.masterChecked = managed;
-          throw new MasterNotRunningException();
+
+        if (this.master == null) {
+          if (sn == null) {
+            throw new MasterNotRunningException();
+          }
+          throw new MasterNotRunningException(sn.toString());
         }
-        throw new MasterNotRunningException(sn.toString());
+        return this.master;
       }
-      return this.master;
     }
 
     private void checkIfBaseNodeAvailable() throws MasterNotRunningException {

src/test/java/org/apache/hadoop/hbase/client/TestFromClientSide.java

@@ -44,6 +44,8 @@ import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.SynchronousQueue;
 import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
@@ -67,6 +69,7 @@ import org.apache.hadoop.hbase.regionserver.HRegion;
 import org.apache.hadoop.hbase.regionserver.Store;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.io.DataInputBuffer;
+import org.apache.hadoop.hbase.client.HTable.DaemonThreadFactory;
 import org.apache.hadoop.hbase.client.metrics.ScanMetrics;
 import org.junit.After;
 import org.junit.AfterClass;
@@ -3851,6 +3854,29 @@ public class TestFromClientSide {
     }
   }
 
+  /**
+   * simple test that just executes parts of the client
+   * API that accept a pre-created HConnction instance
+   *
+   * @throws IOException
+   */
+  @Test
+  public void testUnmanagedHConnection() throws IOException {
+    final byte[] tableName = Bytes.toBytes("testUnmanagedHConnection");
+    TEST_UTIL.createTable(tableName, HConstants.CATALOG_FAMILY);
+    HConnection conn = HConnectionManager.createConnection(TEST_UTIL
+        .getConfiguration());
+    ExecutorService pool = new ThreadPoolExecutor(1, Integer.MAX_VALUE,
+        60, TimeUnit.SECONDS,
+        new SynchronousQueue<Runnable>(),
+        new DaemonThreadFactory());
+    ((ThreadPoolExecutor)pool).allowCoreThreadTimeOut(true);
+    HTable t = new HTable(tableName, conn, pool);
+    HBaseAdmin ha = new HBaseAdmin(conn);
+    assertTrue(ha.tableExists(tableName));
+    assertTrue(t.get(new Get(ROW)).isEmpty());
+  }
+
   @Test
   public void testMiscHTableStuff() throws IOException {
     final byte[] tableAname = Bytes.toBytes("testMiscHTableStuffA");