Minor cleanup.

src/main/java/com/zaxxer/hikari/pool/HikariPool.java

@@ -106,9 +106,6 @@ public class HikariPool implements HikariPoolMBean, IBagStateListener
    private final SuspendResumeLock suspendResumeLock;
    private final AtomicReference<Throwable> lastConnectionFailure;
 
-   private final String username;
-   private final String password;
-
    private volatile MetricsTracker metricsTracker;
    private volatile boolean isRecordMetrics;
 
@@ -120,8 +117,6 @@ public class HikariPool implements HikariPoolMBean, IBagStateListener
    public HikariPool(HikariConfig config)
     {
       this.configuration = config;
-      this.username = config.getUsername();
-      this.password = config.getPassword();
 
       this.poolUtils = new PoolUtilities(config);
       this.dataSource = poolUtils.initializeDataSource();
@@ -147,8 +142,8 @@ public class HikariPool implements HikariPoolMBean, IBagStateListener
       this.addConnectionExecutor = createThreadPoolExecutor(config.getMaximumPoolSize(), "Hikari connection filler (pool " + config.getPoolName() + ")", config.getThreadFactory(), new ThreadPoolExecutor.DiscardPolicy());
       this.closeConnectionExecutor = createThreadPoolExecutor(4, "Hikari connection closer (pool " + config.getPoolName() + ")", config.getThreadFactory(), new ThreadPoolExecutor.CallerRunsPolicy());
 
-      ThreadFactory threadFactory = config.getThreadFactory() != null ? config.getThreadFactory() : new DefaultThreadFactory("Hikari housekeeper (pool " + config.getPoolName() + ")", true);
       if (config.getScheduledExecutorService() == null) {
+         ThreadFactory threadFactory = config.getThreadFactory() != null ? config.getThreadFactory() : new DefaultThreadFactory("Hikari housekeeper (pool " + config.getPoolName() + ")", true);
          this.houseKeepingExecutorService = new ScheduledThreadPoolExecutor(1, threadFactory, new ThreadPoolExecutor.DiscardPolicy());
          this.houseKeepingExecutorService.scheduleAtFixedRate(new HouseKeeper(), HOUSEKEEPING_PERIOD_MS, HOUSEKEEPING_PERIOD_MS, TimeUnit.MILLISECONDS);
          this.houseKeepingExecutorService.setExecuteExistingDelayedTasksAfterShutdownPolicy(false);
@@ -490,38 +485,43 @@ public class HikariPool implements HikariPoolMBean, IBagStateListener
     */
    private boolean addConnection()
    {
+      final HikariConfig config = configuration;
+
       // Speculative increment of totalConnections with expectation of success
-      if (totalConnections.incrementAndGet() > configuration.getMaximumPoolSize()) {
+      if (totalConnections.incrementAndGet() > config.getMaximumPoolSize()) {
          totalConnections.decrementAndGet(); // Pool is maxed out, so undo speculative increment of totalConnections
-         lastConnectionFailure.set(new SQLException("HikariCP pool " + configuration.getPoolName() +" is at maximum capacity"));
+         lastConnectionFailure.set(new SQLException("Hikari pool " + config.getPoolName() +" is at maximum capacity"));
          return true;
       }
 
       Connection connection = null;
       try {
+         String username = config.getUsername();
+         String password = config.getPassword();
+
          connection = (username == null && password == null) ? dataSource.getConnection() : dataSource.getConnection(username, password);
          
          if (isUseJdbc4Validation && !poolUtils.isJdbc4ValidationSupported(connection)) {
             throw new SQLException("JDBC4 Connection.isValid() method not supported, connection test query must be configured");
          }
-         
+
          final int originalTimeout = poolUtils.getAndSetNetworkTimeout(connection, connectionTimeout);
-         
+
          transactionIsolation = (transactionIsolation < 0 ? connection.getTransactionIsolation() : transactionIsolation);
-         
+         poolUtils.setupConnection(connection, config.getConnectionInitSql(), isAutoCommit, isReadOnly, transactionIsolation, catalog);
-         poolUtils.setupConnection(connection, configuration.getConnectionInitSql(), isAutoCommit, isReadOnly, transactionIsolation, catalog);
+
          poolUtils.setNetworkTimeout(connection, originalTimeout);
          
          connectionBag.add(new PoolBagEntry(connection, this));
          lastConnectionFailure.set(null);
-         LOGGER.debug("Connection {} added to pool {} ", connection, configuration.getPoolName());
+         LOGGER.debug("Connection {} added to pool {} ", connection, config.getPoolName());
          return true;
       }
       catch (Exception e) {
          totalConnections.decrementAndGet(); // We failed, so undo speculative increment of totalConnections
          lastConnectionFailure.set(e);
          if (poolState == POOL_NORMAL) {
-            LOGGER.debug("Connection attempt to database in pool {} failed: {}", configuration.getPoolName(), e.getMessage(), e);
+            LOGGER.debug("Connection attempt to database in pool {} failed: {}", config.getPoolName(), e.getMessage(), e);
          }
          poolUtils.quietlyCloseConnection(connection, "exception during connection creation");
          return false;

src/main/java/com/zaxxer/hikari/pool/PoolUtilities.java

@@ -8,6 +8,7 @@ import java.sql.Statement;
 import java.util.Properties;
 import java.util.concurrent.Executor;
 import java.util.concurrent.Executors;
+import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
 
@@ -98,7 +99,7 @@ public final class PoolUtilities
 
       if (dataSource != null) {
          setLoginTimeout(dataSource, config.getConnectionTimeout());
-         createNetworkTimeoutExecutor(dataSource, dsClassName, jdbcUrl);
+         createNetworkTimeoutExecutor(dataSource, dsClassName, jdbcUrl, Math.min(config.getValidationTimeout(), TimeUnit.SECONDS.toMillis(5)));
       }
 
       return dataSource;
@@ -234,7 +235,7 @@ public final class PoolUtilities
    }
 
    // Temporary hack for MySQL issue: http://bugs.mysql.com/bug.php?id=75615
-   private void createNetworkTimeoutExecutor(final DataSource dataSource, final String dsClassName, final String jdbcUrl)
+   private void createNetworkTimeoutExecutor(final DataSource dataSource, final String dsClassName, final String jdbcUrl, final long keepAliveMs)
    {
       if ((dsClassName != null && dsClassName.contains("Mysql")) ||
           (jdbcUrl != null && jdbcUrl.contains("mysql")) ||
@@ -242,8 +243,11 @@ public final class PoolUtilities
          netTimeoutExecutor = new SynchronousExecutor();
       }
       else {
-         netTimeoutExecutor = Executors.newCachedThreadPool(new DefaultThreadFactory("Hikari JDBC-timeout executor", true));
+         ThreadFactory threadFactory = config.getThreadFactory() != null ? config.getThreadFactory() : new DefaultThreadFactory("Hikari JDBC-timeout executor", true);
-         ((ThreadPoolExecutor) netTimeoutExecutor).allowCoreThreadTimeOut(true);
+         ThreadPoolExecutor executor = (ThreadPoolExecutor) Executors.newCachedThreadPool(threadFactory);
+         executor.allowCoreThreadTimeOut(true);
+         executor.setKeepAliveTime(keepAliveMs, TimeUnit.MILLISECONDS);
+         netTimeoutExecutor = executor; 
       }
    }