#10 - ENH: Add DataSourcePool online() and offline()

Author: rbygrave

pom.xml

@@ -22,7 +22,7 @@
     <dependency>
       <groupId>io.ebean</groupId>
       <artifactId>ebean-datasource-api</artifactId>
-      <version>4.3</version>
+      <version>4.4-SNAPSHOT</version>
     </dependency>
 
     <dependency>

src/main/java/io/ebean/datasource/pool/ConnectionPool.java

@@ -140,10 +140,9 @@ public class ConnectionPool implements DataSourcePool {
   private long lastTrimTime;
 
   /**
-   * Assume that the DataSource is up. heartBeat checking will discover when
-   * it goes down, and comes back up again.
+   * HeartBeat checking will discover when it goes down, and comes back up again.
    */
-  private boolean dataSourceUp = true;
+  private boolean dataSourceUp;
 
   /**
    * Stores the dataSourceDown-reason (if there is any)
@@ -182,7 +181,7 @@ public class ConnectionPool implements DataSourcePool {
 
   private final PooledConnectionQueue queue;
 
-  private final Timer heartBeatTimer;
+  private Timer heartBeatTimer;
 
   /**
    * Used to find and close() leaked connections. Leaked connections are
@@ -241,13 +240,13 @@ public ConnectionPool(String name, DataSourceConfig params) {
         this.connectionProps.setProperty(entry.getKey(), entry.getValue());
       }
     }
-
+    checkDriver();
     try {
-      initialise();
-      int freqMillis = heartbeatFreqSecs * 1000;
-      heartBeatTimer = new Timer(name + ".heartBeat", true);
-      if (freqMillis > 0) {
-        heartBeatTimer.scheduleAtFixedRate(new HeartBeatRunnable(), freqMillis, freqMillis);
+      if (!params.isOffline()) {
+        if (config.useInitDatabase()) {
+          initialiseDatabase();
+        }
+        initialise();
       }
     } catch (SQLException e) {
       throw new DataSourceInitialiseException("Error initialising DataSource: " + e.getMessage(), e);
@@ -261,13 +260,12 @@ public void run() {
     }
   }
 
-
   @Override
   public java.util.logging.Logger getParentLogger() throws SQLFeatureNotSupportedException {
     throw new SQLFeatureNotSupportedException("We do not support java.util.logging");
   }
 
-  private void initialise() throws SQLException {
+  private void checkDriver() {
 
     // Ensure database driver is loaded
     try {
@@ -280,25 +278,29 @@ private void initialise() throws SQLException {
     } catch (Throwable e) {
       throw new IllegalStateException("Problem loading Database Driver [" + this.databaseDriver + "]: " + e.getMessage(), e);
     }
+  }
 
-    String transIsolation = TransactionIsolation.getDescription(transactionIsolation);
+  @Override
+  public void online() throws SQLException {
+    initialise();
+  }
+
+  private void initialise() throws SQLException {
 
     //noinspection StringBufferReplaceableByString
     StringBuilder sb = new StringBuilder(70);
     sb.append("DataSourcePool [").append(name);
     sb.append("] autoCommit[").append(autoCommit);
-    sb.append("] transIsolation[").append(transIsolation);
+    sb.append("] transIsolation[").append(TransactionIsolation.getDescription(transactionIsolation));
     sb.append("] min[").append(minConnections);
     sb.append("] max[").append(maxConnections).append("]");
 
     logger.info(sb.toString());
 
-    if (config.useInitDatabase()) {
-      initialiseDatabase();
-    }
-
     try {
+      dataSourceUp = true;
       queue.ensureMinimumConnections();
+      startHeartBeat();
     } catch (SQLException e) {
       if (failOnStart) {
         throw e;
@@ -307,6 +309,14 @@ private void initialise() throws SQLException {
     }
   }
 
+  private void startHeartBeat() {
+    int freqMillis = heartbeatFreqSecs * 1000;
+    if (freqMillis > 0) {
+      heartBeatTimer = new Timer(name + ".heartBeat", true);
+      heartBeatTimer.scheduleAtFixedRate(new HeartBeatRunnable(), freqMillis, freqMillis);
+    }
+  }
+
   /**
    * Initialise the database using the owner credentials if we can't connect using the normal credentials.
    * <p>
@@ -857,6 +867,13 @@ public void shutdown(boolean deregisterDriver) {
     }
   }
 
+  @Override
+  public void offline() {
+    heartBeatTimer.cancel();
+    queue.shutdown();
+    dataSourceUp = false;
+  }
+
   /**
    * Return the default autoCommit setting Connections in this pool will use.
    *

src/main/java/io/ebean/datasource/pool/PooledConnectionQueue.java

@@ -387,6 +387,7 @@ public void shutdown() {
       }
     } finally {
       lock.unlock();
+      doingShutdown = false;
     }
   }
 

src/test/java/io/ebean/datasource/PostgresInitTest.java

@@ -36,7 +36,7 @@ public void test() throws SQLException {
       ds.setOwnerUsername("db_owner");
       ds.setOwnerPassword("test");
 
-      DataSourcePool pool = DataSourceFactory.get().createPool("app", ds);
+      DataSourcePool pool = DataSourceFactory.create("app", ds);
 
       try (Connection connection = pool.getConnection()) {
         try (PreparedStatement statement = connection.prepareStatement("create table my_table (acol integer);")) {

src/test/java/io/ebean/datasource/pool/ConnectionPoolOfflineTest.java

@@ -0,0 +1,69 @@
+package io.ebean.datasource.pool;
+
+import io.ebean.datasource.DataSourceConfig;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.testng.annotations.Test;
+
+import java.sql.SQLException;
+
+import static org.testng.Assert.assertEquals;
+
+public class ConnectionPoolOfflineTest {
+
+  private static final Logger log = LoggerFactory.getLogger(ConnectionPoolOfflineTest.class);
+
+  private DataSourceConfig config() {
+
+    DataSourceConfig config = new DataSourceConfig();
+    config.setDriver("org.h2.Driver");
+    config.setUrl("jdbc:h2:mem:tests");
+    config.setUsername("sa");
+    config.setPassword("");
+    config.setMinConnections(2);
+    config.setMaxConnections(4);
+    config.setOffline(true);
+    config.setHeartbeatFreqSecs(1);
+
+    return config;
+  }
+
+  @Test
+  public void testOffline() throws InterruptedException, SQLException {
+
+    DataSourceConfig config = config();
+
+    ConnectionPool pool = new ConnectionPool("test", config);
+    log.info("pool created ");
+    Thread.sleep(3000);
+
+    assertEquals(0, pool.getStatus(false).getFree());
+    assertEquals(0, pool.getStatus(false).getBusy());
+
+    pool.online();
+    log.info("pool online");
+    assertEquals(2, pool.getStatus(false).getFree());
+    assertEquals(0, pool.getStatus(false).getBusy());
+
+    Thread.sleep(3000);
+
+    pool.offline();
+    log.info("pool offline");
+    assertEquals(0, pool.getStatus(false).getFree());
+    assertEquals(0, pool.getStatus(false).getBusy());
+
+    Thread.sleep(3000);
+
+    pool.online();
+    log.info("pool online");
+    assertEquals(2, pool.getStatus(false).getFree());
+    assertEquals(0, pool.getStatus(false).getBusy());
+    Thread.sleep(3000);
+
+    pool.shutdown(false);
+
+    assertEquals(0, pool.getStatus(false).getFree());
+    assertEquals(0, pool.getStatus(false).getBusy());
+  }
+
+}