Merge pull request #3169 from digitalsonic/master

优化 HighAvailableDataSource 逻辑

src/main/java/com/alibaba/druid/pool/ha/DataSourceCreator.java

@@ -45,8 +45,12 @@ public class DataSourceCreator {
     private List<String> nameList = new ArrayList<String>();
 
     public DataSourceCreator(String file) {
+        this(file, "");
+    }
+
+    public DataSourceCreator(String file, String propertyPrefix) {
         loadProperties(file);
-        loadNameList();
+        loadNameList(propertyPrefix);
     }
 
     public Map<String, DataSource> createMap(HighAvailableDataSource haDataSource) throws SQLException {
@@ -62,8 +66,12 @@ public class DataSourceCreator {
             String username = properties.getProperty(n + ".username");
             String password = properties.getProperty(n + ".password");
             LOG.info("Creating " + n + " with url[" + url + "] and username[" + username + "].");
-            DruidDataSource dataSource = create(n, url, username, password, haDataSource);
-            map.put(n, dataSource);
+            try {
+                DruidDataSource dataSource = create(n, url, username, password, haDataSource);
+                map.put(n, dataSource);
+            } catch(Exception e) {
+                LOG.error("Can NOT create DruidDataSource for " + n, e);
+            }
         }
         LOG.info(map.size() + " DruidDataSource(s) created. ");
         return map;
@@ -120,10 +128,14 @@ public class DataSourceCreator {
         return dataSource;
     }
 
-    private void loadNameList() {
+    private void loadNameList(String propertyPrefix) {
         Set<String> names = new HashSet<String>();
         for (String n : properties.stringPropertyNames()) {
-            if (n.contains(".url")) {
+            if (propertyPrefix != null && !propertyPrefix.isEmpty()
+                    && !n.startsWith(propertyPrefix)) {
+                continue;
+            }
+            if (n.endsWith(".url")) {
                 names.add(n.split("\\.url")[0]);
             }
         }
@@ -168,4 +180,8 @@ public class DataSourceCreator {
             LOG.warn("File " + file + " can't be loaded!");
         }
     }
+
+    public List<String> getNameList() {
+        return nameList;
+    }
 }

src/main/java/com/alibaba/druid/pool/ha/HighAvailableDataSource.java

@@ -34,8 +34,8 @@ import com.alibaba.druid.pool.DruidAbstractDataSource;
 import com.alibaba.druid.pool.DruidDataSource;
 import com.alibaba.druid.pool.WrapperAdapter;
 import com.alibaba.druid.pool.ha.selector.DataSourceSelector;
+import com.alibaba.druid.pool.ha.selector.DataSourceSelectorEnum;
 import com.alibaba.druid.pool.ha.selector.DataSourceSelectorFactory;
-import com.alibaba.druid.pool.ha.selector.RandomDataSourceSelector;
 import com.alibaba.druid.support.logging.Log;
 import com.alibaba.druid.support.logging.LogFactory;
 
@@ -87,10 +87,11 @@ public class HighAvailableDataSource extends WrapperAdapter implements DataSourc
     // Properties copied from DruidAbstractDataSource END
 
     private Map<String, DataSource> dataSourceMap = new ConcurrentHashMap<String, DataSource>();
-    private DataSourceSelector selector = new RandomDataSourceSelector(this);
+    private DataSourceSelector selector;
     private String dataSourceFile = DEFAULT_DATA_SOURCE_FILE;
+    private String propertyPrefix = "";
 
-    private boolean inited = false;
+    private volatile boolean inited = false;
 
     public void init() throws SQLException {
         if (inited) {
@@ -101,10 +102,10 @@ public class HighAvailableDataSource extends WrapperAdapter implements DataSourc
                 return;
             }
             if (dataSourceMap == null || dataSourceMap.isEmpty()) {
-                dataSourceMap = new DataSourceCreator(dataSourceFile).createMap(this);
+                dataSourceMap = new DataSourceCreator(dataSourceFile, propertyPrefix).createMap(this);
             }
             if (selector == null) {
-                selector = new RandomDataSourceSelector(this);
+                setSelector(DataSourceSelectorEnum.RANDOM.getName());
             }
             if (dataSourceMap == null || dataSourceMap.isEmpty()) {
                 LOG.warn("There is NO DataSource available!!! Please check your configuration.");
@@ -147,6 +148,14 @@ public class HighAvailableDataSource extends WrapperAdapter implements DataSourc
         this.dataSourceFile = dataSourceFile;
     }
 
+    public String getPropertyPrefix() {
+        return propertyPrefix;
+    }
+
+    public void setPropertyPrefix(String propertyPrefix) {
+        this.propertyPrefix = propertyPrefix;
+    }
+
     public void setDataSourceMap(Map<String, DataSource> dataSourceMap) {
         if (dataSourceMap != null) {
             this.dataSourceMap = dataSourceMap;
@@ -158,11 +167,9 @@ public class HighAvailableDataSource extends WrapperAdapter implements DataSourc
     }
 
     public void setSelector(String name) {
-        if (name != null && this.selector != null && this.selector.isSame(name)) {
-            return;
-        }
         DataSourceSelector selector = DataSourceSelectorFactory.getSelector(name, this);
         if (selector != null) {
+            selector.init();
             setDataSourceSelector(selector);
         }
     }
@@ -181,7 +188,7 @@ public class HighAvailableDataSource extends WrapperAdapter implements DataSourc
 
     @Override
     public Connection getConnection(String username, String password) throws SQLException {
-        throw new UnsupportedOperationException("Not supported by DruidDataSource");
+        throw new UnsupportedOperationException("Not supported by HighAvailableDataSource.");
     }
 
     @Override
@@ -221,7 +228,15 @@ public class HighAvailableDataSource extends WrapperAdapter implements DataSourc
     }
 
     public void setConnectProperties(Properties connectProperties) {
-        this.connectProperties = connectProperties;
+        if (connectProperties == null) {
+            connectProperties = new Properties();
+        }
+
+        if (this.connectProperties != null) {
+            this.connectProperties.putAll(connectProperties);
+        } else {
+            this.connectProperties = connectProperties;
+        }
     }
 
     public int getInitialSize() {
@@ -406,6 +421,32 @@ public class HighAvailableDataSource extends WrapperAdapter implements DataSourc
 
     public void setConnectionProperties(String connectionProperties) {
         this.connectionProperties = connectionProperties;
+
+        // COPIED FROM DruidAbstractDataSource.setConnectionProperties()
+
+        if (connectionProperties == null || connectionProperties.trim().length() == 0) {
+            setConnectProperties(null);
+            return;
+        }
+
+        String[] entries = connectionProperties.split(";");
+        Properties properties = new Properties();
+        for (int i = 0; i < entries.length; i++) {
+            String entry = entries[i];
+            if (entry.length() > 0) {
+                int index = entry.indexOf('=');
+                if (index > 0) {
+                    String name = entry.substring(0, index);
+                    String value = entry.substring(index + 1);
+                    properties.setProperty(name, value);
+                } else {
+                    // no value is empty string which is how java.util.Properties works
+                    properties.setProperty(entry, "");
+                }
+            }
+        }
+
+        setConnectProperties(properties);
     }
 
     public String getFilters() {

src/main/java/com/alibaba/druid/pool/ha/selector/DataSourceSelector.java

@@ -26,6 +26,6 @@ import javax.sql.DataSource;
 public interface DataSourceSelector {
     DataSource get();
     void setTarget(String name);
-    boolean isSame(String name);
     String getName();
+    void init();
 }

src/main/java/com/alibaba/druid/pool/ha/selector/DataSourceSelectorEnum.java

@@ -0,0 +1,53 @@
+package com.alibaba.druid.pool.ha.selector;
+
+import com.alibaba.druid.pool.ha.HighAvailableDataSource;
+import com.alibaba.druid.support.logging.Log;
+import com.alibaba.druid.support.logging.LogFactory;
+
+/**
+ * An enum holding the names and classes of DataSourceSelector.
+ *
+ * @author DigitalSonic
+ */
+public enum DataSourceSelectorEnum {
+    BY_NAME("byName", NamedDataSourceSelector.class),
+    RANDOM("random", RandomDataSourceSelector.class),
+    STICKY_RANDOM("stickyRandom", StickyRandomDataSourceSelector.class);
+
+    private final static Log LOG = LogFactory.getLog(DataSourceSelectorEnum.class);
+    private String name;
+    private Class<? extends DataSourceSelector> clazz;
+
+    DataSourceSelectorEnum(String name, Class<? extends DataSourceSelector> clazz) {
+        this.name = name;
+        this.clazz = clazz;
+    }
+
+    /**
+     * Create a new instance of the DataSourceSelector represented by this enum.
+     *
+     * @return null if dataSource is not given or exception occurred while creating new instance
+     */
+    public DataSourceSelector newInstance(HighAvailableDataSource dataSource) {
+        if (dataSource == null) {
+            LOG.warn("You should provide an instance of HighAvailableDataSource!");
+            return null;
+        }
+
+        DataSourceSelector selector = null;
+        try {
+            selector = clazz.getDeclaredConstructor(HighAvailableDataSource.class).newInstance(dataSource);
+        } catch (Exception e) {
+            LOG.error("Can not create new instance of " + clazz.getName(), e);
+        }
+        return selector;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public Class<? extends DataSourceSelector> getClazz() {
+        return clazz;
+    }
+}

src/main/java/com/alibaba/druid/pool/ha/selector/DataSourceSelectorFactory.java

@@ -23,11 +23,16 @@ import com.alibaba.druid.pool.ha.HighAvailableDataSource;
  * @author DigitalSonic
  */
 public class DataSourceSelectorFactory {
+    /**
+     * Get a new instance of the given selector name.
+     *
+     * @return null if the given name do not represent a DataSourceSelector
+     */
     public static DataSourceSelector getSelector(String name, HighAvailableDataSource highAvailableDataSource) {
-        if ("random".equalsIgnoreCase(name)) {
-            return new RandomDataSourceSelector(highAvailableDataSource);
-        } else if ("byName".equalsIgnoreCase(name)) {
-            return new NamedDataSourceSelector(highAvailableDataSource);
+        for (DataSourceSelectorEnum e : DataSourceSelectorEnum.values()) {
+            if (e.getName().equalsIgnoreCase(name)) {
+                return e.newInstance(highAvailableDataSource);
+            }
         }
         return null;
     }

src/main/java/com/alibaba/druid/pool/ha/selector/NamedDataSourceSelector.java

@@ -37,13 +37,12 @@ public class NamedDataSourceSelector implements DataSourceSelector {
     }
 
     @Override
-    public boolean isSame(String name) {
-        return getName().equalsIgnoreCase(name);
+    public void init() {
     }
 
     @Override
     public String getName() {
-        return "byName";
+        return DataSourceSelectorEnum.BY_NAME.getName();
     }
 
     @Override

src/main/java/com/alibaba/druid/pool/ha/selector/RandomDataSourceRecoverThread.java

@@ -32,7 +32,8 @@ import com.alibaba.druid.util.JdbcUtils;
 public class RandomDataSourceRecoverThread implements Runnable {
     private final static Log LOG = LogFactory.getLog(RandomDataSourceRecoverThread.class);
     private RandomDataSourceSelector selector;
-    private int sleepSeconds = 30;
+    private int sleepSeconds = 120;
+    private int validationSleepSeconds = 0;
 
     public RandomDataSourceRecoverThread(RandomDataSourceSelector selector) {
         this.selector = selector;
@@ -62,20 +63,29 @@ public class RandomDataSourceRecoverThread implements Runnable {
         Connection connection = null;
         try {
             connection = dataSource.getConnection();
+            sleepBeforeValidation();
             dataSource.validateConnection(connection);
             LOG.info(dataSource.getName() + " is available now.");
             selector.removeBlacklist(dataSource);
         } catch(Exception e) {
             LOG.warn("DataSource[" + dataSource.getName() + "] is still unavailable. Exception: "
                     + e.getMessage());
-            if (connection != null) {
-                dataSource.discardConnection(connection);
-            }
         } finally {
             JdbcUtils.close(connection);
         }
     }
 
+    private void sleepBeforeValidation() {
+        if (validationSleepSeconds > 0) {
+            try {
+                LOG.debug("Sleep " + validationSleepSeconds + " second(s) before validation.");
+                Thread.sleep(validationSleepSeconds * 1000);
+            } catch (InterruptedException e) {
+                // ignore
+            }
+        }
+    }
+
     private void sleep() {
         try {
             Thread.sleep(sleepSeconds * 1000);
@@ -84,7 +94,19 @@ public class RandomDataSourceRecoverThread implements Runnable {
         }
     }
 
+    public int getSleepSeconds() {
+        return sleepSeconds;
+    }
+
     public void setSleepSeconds(int sleepSeconds) {
         this.sleepSeconds = sleepSeconds;
     }
+
+    public int getValidationSleepSeconds() {
+        return validationSleepSeconds;
+    }
+
+    public void setValidationSleepSeconds(int validationSleepSeconds) {
+        this.validationSleepSeconds = validationSleepSeconds;
+    }
 }

src/main/java/com/alibaba/druid/pool/ha/selector/RandomDataSourceSelector.java

@@ -20,6 +20,7 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Properties;
 import java.util.Random;
 import java.util.concurrent.CopyOnWriteArrayList;
 
@@ -36,6 +37,12 @@ import com.alibaba.druid.support.logging.LogFactory;
  * @author DigitalSonic
  */
 public class RandomDataSourceSelector implements DataSourceSelector {
+    private static final String PROP_PREFIX = "druid.ha.random.";
+    public static final String PROP_CHECKING_INTERVAL = PROP_PREFIX + "checkingIntervalSeconds";
+    public static final String PROP_RECOVERY_INTERVAL = PROP_PREFIX + "recoveryIntervalSeconds";
+    public static final String PROP_VALIDATION_SLEEP = PROP_PREFIX + "validationSleepSeconds";
+    public static final String PROP_BLACKLIST_THRESHOLD = PROP_PREFIX + "blacklistThreshold";
+
     private final static Log LOG = LogFactory.getLog(RandomDataSourceSelector.class);
 
     private Random random = new Random();
@@ -44,26 +51,32 @@ public class RandomDataSourceSelector implements DataSourceSelector {
     private RandomDataSourceValidateThread validateThread;
     private RandomDataSourceRecoverThread recoverThread;
 
+    private int checkingIntervalSeconds = 15;
+    private int recoveryIntervalSeconds = 120;
+    private int validationSleepSeconds = 0;
+    private int blacklistThreshold = 3;
+
     public RandomDataSourceSelector(HighAvailableDataSource highAvailableDataSource) {
         this.highAvailableDataSource = highAvailableDataSource;
+    }
+
+    @Override
+    public void init() {
+        if (highAvailableDataSource == null) {
+            LOG.warn("highAvailableDataSource is NULL!");
+            return;
+        }
         if (!highAvailableDataSource.isTestOnBorrow() && !highAvailableDataSource.isTestOnReturn()) {
-            validateThread = new RandomDataSourceValidateThread(this);
-            recoverThread = new RandomDataSourceRecoverThread(this);
-            new Thread(validateThread, "RandomDataSourceSelector-validate-thread").start();
-            new Thread(recoverThread, "RandomDataSourceSelector-recover-thread").start();
+            loadProperties();
+            initThreads();
         } else {
             LOG.info("testOnBorrow or testOnReturn has been set to true, ignore validateThread");
         }
     }
 
-    @Override
-    public boolean isSame(String name) {
-        return getName().equalsIgnoreCase(name);
-    }
-
     @Override
     public String getName() {
-        return "random";
+        return DataSourceSelectorEnum.RANDOM.getName();
     }
 
     @Override
@@ -106,6 +119,10 @@ public class RandomDataSourceSelector implements DataSourceSelector {
         return blacklist;
     }
 
+    public boolean containInBlacklist(DataSource dataSource) {
+        return dataSource != null && blacklist.contains(dataSource);
+    }
+
     public void addBlacklist(DataSource dataSource) {
         if (dataSource != null && !blacklist.contains(dataSource)) {
             blacklist.add(dataSource);
@@ -116,7 +133,7 @@ public class RandomDataSourceSelector implements DataSourceSelector {
     }
 
     public void removeBlacklist(DataSource dataSource) {
-        if (dataSource != null && blacklist.contains(dataSource)) {
+        if (containInBlacklist(dataSource)) {
             blacklist.remove(dataSource);
             if (dataSource instanceof DruidDataSource) {
                 ((DruidDataSource) dataSource).setTestOnReturn(highAvailableDataSource.isTestOnReturn());
@@ -124,11 +141,96 @@ public class RandomDataSourceSelector implements DataSourceSelector {
         }
     }
 
+    private void loadProperties() {
+        checkingIntervalSeconds = loadInteger(PROP_CHECKING_INTERVAL, checkingIntervalSeconds);
+        recoveryIntervalSeconds = loadInteger(PROP_RECOVERY_INTERVAL, recoveryIntervalSeconds);
+        validationSleepSeconds = loadInteger(PROP_VALIDATION_SLEEP, validationSleepSeconds);
+        blacklistThreshold = loadInteger(PROP_BLACKLIST_THRESHOLD, blacklistThreshold);
+    }
+
+    private int loadInteger(String name, int defaultValue) {
+        if (name == null) {
+            return defaultValue;
+        }
+
+        Properties properties = highAvailableDataSource.getConnectProperties();
+        int value = defaultValue;
+        try {
+            if (properties.containsKey(name)) {
+                value = Integer.parseInt(properties.getProperty(name));
+            }
+        } catch (Exception e) {
+            LOG.error("Exception occurred while parsing " + name, e);
+        }
+        return value;
+    }
+
+    private void initThreads() {
+        if (validateThread == null) {
+            validateThread = new RandomDataSourceValidateThread(this);
+            validateThread.setCheckingIntervalSeconds(checkingIntervalSeconds);
+            validateThread.setValidationSleepSeconds(validationSleepSeconds);
+            validateThread.setBlacklistThreshold(blacklistThreshold);
+        }
+        new Thread(validateThread, "RandomDataSourceSelector-validate-thread").start();
+
+        if (recoverThread == null) {
+            recoverThread = new RandomDataSourceRecoverThread(this);
+            recoverThread.setSleepSeconds(recoveryIntervalSeconds);
+            recoverThread.setValidationSleepSeconds(validationSleepSeconds);
+        }
+        new Thread(recoverThread, "RandomDataSourceSelector-recover-thread").start();
+    }
+
+    public HighAvailableDataSource getHighAvailableDataSource() {
+        return highAvailableDataSource;
+    }
+
     public RandomDataSourceValidateThread getValidateThread() {
         return validateThread;
     }
 
+    public void setValidateThread(RandomDataSourceValidateThread validateThread) {
+        this.validateThread = validateThread;
+    }
+
     public RandomDataSourceRecoverThread getRecoverThread() {
         return recoverThread;
     }
+
+    public void setRecoverThread(RandomDataSourceRecoverThread recoverThread) {
+        this.recoverThread = recoverThread;
+    }
+
+    public int getCheckingIntervalSeconds() {
+        return checkingIntervalSeconds;
+    }
+
+    public void setCheckingIntervalSeconds(int checkingIntervalSeconds) {
+        this.checkingIntervalSeconds = checkingIntervalSeconds;
+    }
+
+    public int getRecoveryIntervalSeconds() {
+        return recoveryIntervalSeconds;
+    }
+
+    public void setRecoveryIntervalSeconds(int recoveryIntervalSeconds) {
+        this.recoveryIntervalSeconds = recoveryIntervalSeconds;
+    }
+
+    public int getValidationSleepSeconds() {
+        return validationSleepSeconds;
+    }
+
+    public void setValidationSleepSeconds(int validationSleepSeconds) {
+        this.validationSleepSeconds = validationSleepSeconds;
+    }
+
+    public int getBlacklistThreshold() {
+        return blacklistThreshold;
+    }
+
+    public void setBlacklistThreshold(int blacklistThreshold) {
+        this.blacklistThreshold = blacklistThreshold;
+    }
 }

src/main/java/com/alibaba/druid/pool/ha/selector/RandomDataSourceValidateThread.java

@@ -18,9 +18,14 @@ package com.alibaba.druid.pool.ha.selector;
 import java.sql.Connection;
 import java.sql.Driver;
 import java.sql.SQLException;
-import java.util.HashMap;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Map;
 import java.util.Properties;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 import javax.sql.DataSource;
 
@@ -31,17 +36,18 @@ import com.alibaba.druid.util.JdbcUtils;
 
 /**
  * A Thread trying to test all DataSource provided by HADataSource.
- * If a DataSource failed this test for 3 times, it will be put into a blacklist.
+ * If a DataSource failed this test for 3 times (default value), it will be put into a blacklist.
  *
  * @author DigitalSonic
  */
 public class RandomDataSourceValidateThread implements Runnable {
     private final static Log LOG = LogFactory.getLog(RandomDataSourceValidateThread.class);
-    private int sleepSeconds = 30;
+    private int checkingIntervalSeconds = 15;
+    private int validationSleepSeconds = 0;
     private int blacklistThreshold = 3;
-
     private RandomDataSourceSelector selector;
-    private Map<String, Integer> errorCounts = new HashMap<String, Integer>();
+    private ExecutorService checkExecutor = Executors.newFixedThreadPool(5);
+    private Map<String, Integer> errorCounts = new ConcurrentHashMap<String, Integer>();
 
     public RandomDataSourceValidateThread(RandomDataSourceSelector selector) {
         this.selector = selector;
@@ -54,12 +60,29 @@ public class RandomDataSourceValidateThread implements Runnable {
                 checkAllDataSources();
                 maintainBlacklist();
             }
-            try {
-                Thread.sleep(sleepSeconds * 1000);
-            } catch (InterruptedException e) {
-                // ignore
+            sleepForNextValidation();
+        }
+    }
+
+    private void sleepForNextValidation() {
+        int errorCountBelowThreshold = 0;
+
+        for (int count : errorCounts.values()) {
+            if (count > 0 && count < blacklistThreshold && count > errorCountBelowThreshold) {
+                errorCountBelowThreshold = count;
             }
         }
+
+        int newSleepSeconds = checkingIntervalSeconds / (errorCountBelowThreshold + 1);
+        if (newSleepSeconds < 1) {
+            newSleepSeconds = 1;
+        }
+        try {
+            LOG.debug("Sleep " + newSleepSeconds + " second(s) until next checking.");
+            Thread.sleep(newSleepSeconds * 1000);
+        } catch (InterruptedException e) {
+            // ignore
+        }
     }
 
     private void maintainBlacklist() {
@@ -67,7 +90,8 @@ public class RandomDataSourceValidateThread implements Runnable {
         for (Map.Entry<String, Integer> e : errorCounts.entrySet()) {
             if (e.getValue() <= 0) {
                 selector.removeBlacklist(dataSourceMap.get(e.getKey()));
-            } else if (e.getValue() >= blacklistThreshold) {
+            } else if (e.getValue() >= blacklistThreshold
+                    && !selector.containInBlacklist(dataSourceMap.get(e.getKey()))) {
                 LOG.warn("Adding " + e.getKey() + " to blacklist.");
                 selector.addBlacklist(dataSourceMap.get(e.getKey()));
             }
@@ -76,21 +100,41 @@ public class RandomDataSourceValidateThread implements Runnable {
 
     private void checkAllDataSources() {
         Map<String, DataSource> dataSourceMap = selector.getDataSourceMap();
-        for (Map.Entry<String, DataSource> e : dataSourceMap.entrySet()) {
+        List<Callable<Boolean>> tasks = new ArrayList<Callable<Boolean>>();
+
+        for (final Map.Entry<String, DataSource> e : dataSourceMap.entrySet()) {
             if (!(e.getValue() instanceof DruidDataSource)) {
                 continue;
             }
-            boolean flag = check(e.getKey(), (DruidDataSource) e.getValue());
 
-            if (flag) {
-                errorCounts.put(e.getKey(), 0);
-            } else {
-                if (!errorCounts.containsKey(e.getKey())) {
-                    errorCounts.put(e.getKey(), 0);
-                }
-                int count = errorCounts.get(e.getKey());
-                errorCounts.put(e.getKey(), count + 1);
+            if (selector.containInBlacklist(e.getValue())) {
+                LOG.debug(e.getKey() + " is already in blacklist, skip.");
+                continue;
             }
+
+            tasks.add(new Callable<Boolean>() {
+                @Override
+                public Boolean call() {
+                    boolean flag = check(e.getKey(), (DruidDataSource) e.getValue());
+
+                    if (flag) {
+                        errorCounts.put(e.getKey(), 0);
+                    } else {
+                        if (!errorCounts.containsKey(e.getKey())) {
+                            errorCounts.put(e.getKey(), 0);
+                        }
+                        int count = errorCounts.get(e.getKey());
+                        errorCounts.put(e.getKey(), count + 1);
+                    }
+
+                    return flag;
+                }
+            });
+        }
+        try {
+            checkExecutor.invokeAll(tasks);
+        } catch (Exception e) {
+            LOG.warn("Exception occurred while checking DataSource.", e);
         }
     }
 
@@ -110,8 +154,9 @@ public class RandomDataSourceValidateThread implements Runnable {
             info.setProperty("password", password);
         }
         try {
-            LOG.debug("Validating " + name + " every " + sleepSeconds + " seconds.");
+            LOG.debug("Validating " + name + " every " + checkingIntervalSeconds + " seconds.");
             conn = driver.connect(url, info);
+            sleepBeforeValidation();
             dataSource.validateConnection(conn);
         } catch (SQLException e) {
             LOG.warn("Validation FAILED for " + name + " with url [" + url + "] and username ["
@@ -124,8 +169,36 @@ public class RandomDataSourceValidateThread implements Runnable {
         return result;
     }
 
-    public void setSleepSeconds(int sleepSeconds) {
-        this.sleepSeconds = sleepSeconds;
+    private void sleepBeforeValidation() {
+        if (validationSleepSeconds <= 0) {
+            return;
+        }
+        try {
+            LOG.debug("Sleep " + validationSleepSeconds + " second(s) before validation.");
+            Thread.sleep(validationSleepSeconds * 1000L);
+        } catch (InterruptedException e) {
+            // ignore
+        }
+    }
+
+    public int getCheckingIntervalSeconds() {
+        return checkingIntervalSeconds;
+    }
+
+    public void setCheckingIntervalSeconds(int checkingIntervalSeconds) {
+        this.checkingIntervalSeconds = checkingIntervalSeconds;
+    }
+
+    public int getValidationSleepSeconds() {
+        return validationSleepSeconds;
+    }
+
+    public void setValidationSleepSeconds(int validationSleepSeconds) {
+        this.validationSleepSeconds = validationSleepSeconds;
+    }
+
+    public int getBlacklistThreshold() {
+        return blacklistThreshold;
     }
 
     public void setBlacklistThreshold(int blacklistThreshold) {

src/main/java/com/alibaba/druid/pool/ha/selector/StickyDataSourceHolder.java

@@ -0,0 +1,40 @@
+package com.alibaba.druid.pool.ha.selector;
+
+import javax.sql.DataSource;
+
+/**
+ * A class holding DataSource reference and retrieving time.
+ *
+ * @author DigitalSonic
+ */
+public class StickyDataSourceHolder {
+    private long retrievingTime = System.currentTimeMillis();
+    private DataSource dataSource;
+
+    public StickyDataSourceHolder() {
+    }
+
+    public StickyDataSourceHolder(DataSource dataSource) {
+        this.dataSource = dataSource;
+    }
+
+    public boolean isValid() {
+        return retrievingTime > 0 && dataSource != null;
+    }
+
+    public long getRetrievingTime() {
+        return retrievingTime;
+    }
+
+    public void setRetrievingTime(long retrievingTime) {
+        this.retrievingTime = retrievingTime;
+    }
+
+    public DataSource getDataSource() {
+        return dataSource;
+    }
+
+    public void setDataSource(DataSource dataSource) {
+        this.dataSource = dataSource;
+    }
+}

src/main/java/com/alibaba/druid/pool/ha/selector/StickyRandomDataSourceSelector.java

@@ -0,0 +1,68 @@
+package com.alibaba.druid.pool.ha.selector;
+
+import com.alibaba.druid.pool.DruidDataSource;
+import com.alibaba.druid.pool.ha.HighAvailableDataSource;
+import com.alibaba.druid.support.logging.Log;
+import com.alibaba.druid.support.logging.LogFactory;
+
+import javax.sql.DataSource;
+
+/**
+ * An extend selector based on RandomDataSourceSelector which can stick a DataSource to a Thread in a while.
+ *
+ * @author DigitalSonic
+ * @see RandomDataSourceSelector
+ * @see StickyDataSourceHolder
+ */
+public class StickyRandomDataSourceSelector extends RandomDataSourceSelector {
+    private final static Log LOG = LogFactory.getLog(StickyRandomDataSourceSelector.class);
+
+    private ThreadLocal<StickyDataSourceHolder> holders = new ThreadLocal<StickyDataSourceHolder>();
+
+    private int expireSeconds = 5;
+
+    public StickyRandomDataSourceSelector(HighAvailableDataSource highAvailableDataSource) {
+        super(highAvailableDataSource);
+    }
+
+    @Override
+    public String getName() {
+        return DataSourceSelectorEnum.STICKY_RANDOM.getName();
+    }
+
+    @Override
+    public DataSource get() {
+        StickyDataSourceHolder holder = holders.get();
+        if (holder != null && isValid(holder) && !isExpired(holder)) {
+            LOG.debug("Return the sticky DataSource " + holder.getDataSource().toString() + " directly.");
+            return holder.getDataSource();
+        }
+        LOG.debug("Return a random DataSource.");
+        DataSource dataSource = super.get();
+        holder = new StickyDataSourceHolder(dataSource);
+        holders.remove();
+        holders.set(holder);
+        return dataSource;
+    }
+
+    private boolean isValid(StickyDataSourceHolder holder) {
+        boolean flag = holder.isValid() && !getBlacklist().contains(holder.getDataSource());
+        if (!(holder.getDataSource() instanceof DruidDataSource) || !flag) {
+            return flag;
+        }
+        DruidDataSource dataSource = (DruidDataSource) holder.getDataSource();
+        return flag && dataSource.getActiveCount() < dataSource.getMaxActive();
+    }
+
+    private boolean isExpired(StickyDataSourceHolder holder) {
+        return System.currentTimeMillis() - holder.getRetrievingTime() > expireSeconds * 1000;
+    }
+
+    public int getExpireSeconds() {
+        return expireSeconds;
+    }
+
+    public void setExpireSeconds(int expireSeconds) {
+        this.expireSeconds = expireSeconds;
+    }
+}

src/main/java/com/alibaba/druid/pool/vendor/MySqlExceptionSorter.java

@@ -38,7 +38,7 @@ public class MySqlExceptionSorter implements ExceptionSorter {
         }
         
         switch (errorCode) {
-        // Communications Errors
+            // Communications Errors
             case 1040: // ER_CON_COUNT_ERROR
             case 1042: // ER_BAD_HOST_ERROR
             case 1043: // ER_HANDSHAKE_ERROR
@@ -46,21 +46,23 @@ public class MySqlExceptionSorter implements ExceptionSorter {
             case 1081: // ER_IPSOCK_ERROR
             case 1129: // ER_HOST_IS_BLOCKED
             case 1130: // ER_HOST_NOT_PRIVILEGED
-                // Authentication Errors
+            // Authentication Errors
             case 1045: // ER_ACCESS_DENIED_ERROR
-                // Resource errors
+            // Resource errors
             case 1004: // ER_CANT_CREATE_FILE
             case 1005: // ER_CANT_CREATE_TABLE
             case 1015: // ER_CANT_LOCK
             case 1021: // ER_DISK_FULL
             case 1041: // ER_OUT_OF_RESOURCES
-                // Out-of-memory errors
+            // Out-of-memory errors
             case 1037: // ER_OUTOFMEMORY
             case 1038: // ER_OUT_OF_SORTMEMORY
-                // Access denied
+            // Access denied
             case 1142: // ER_TABLEACCESS_DENIED_ERROR
             case 1227: // ER_SPECIFIC_ACCESS_DENIED_ERROR
 
+            case 1023: // ER_ERROR_ON_CLOSE
+
             case 1290: // ER_OPTION_PREVENTS_STATEMENT
                 return true;
             default:

src/main/java/com/alibaba/druid/pool/vendor/MySqlValidConnectionChecker.java

@@ -99,7 +99,7 @@ public class MySqlValidConnectionChecker extends ValidConnectionCheckerAdapter i
             }
 
             if (clazz.isAssignableFrom(conn.getClass())) {
-                if (validationQueryTimeout < 0) {
+                if (validationQueryTimeout <= 0) {
                     validationQueryTimeout = DEFAULT_VALIDATION_QUERY_TIMEOUT;
                 }
 

src/main/java/com/alibaba/druid/pool/vendor/OracleValidConnectionChecker.java

@@ -74,7 +74,7 @@ public class OracleValidConnectionChecker extends ValidConnectionCheckerAdapter
             return true;
         }
 
-        int queryTimeout = validationQueryTimeout < 0 ? timeout : validationQueryTimeout;
+        int queryTimeout = validationQueryTimeout <= 0 ? timeout : validationQueryTimeout;
 
         Statement stmt = null;
         ResultSet rs = null;

src/main/java/com/alibaba/druid/pool/vendor/PGValidConnectionChecker.java

@@ -55,7 +55,7 @@ public class PGValidConnectionChecker extends ValidConnectionCheckerAdapter impl
             conn = ((ConnectionProxy) conn).getRawObject();
         }
 
-        int queryTimeout = validationQueryTimeout < 0 ? defaultQueryTimeout : validationQueryTimeout;
+        int queryTimeout = validationQueryTimeout <= 0 ? defaultQueryTimeout : validationQueryTimeout;
 
         Statement stmt = null;
         ResultSet rs = null;

src/test/java/com/alibaba/druid/pool/ha/DataSourceCreatorTest.java

@@ -3,11 +3,29 @@ package com.alibaba.druid.pool.ha;
 import org.junit.Test;
 
 import javax.sql.DataSource;
+import java.util.List;
 import java.util.Map;
 
 import static org.junit.Assert.*;
 
 public class DataSourceCreatorTest {
+    @Test
+    public void testNameList() {
+        String file = "/com/alibaba/druid/pool/ha/ha-with-prefix-datasource.properties";
+        DataSourceCreator creator = new DataSourceCreator(file, "prefix1");
+        List<String> list = creator.getNameList();
+        assertFalse(list.isEmpty());
+        assertEquals(1, list.size());
+        assertEquals("prefix1.foo", list.get(0));
+
+        creator = new DataSourceCreator(file);
+        list = creator.getNameList();
+        assertEquals(3, list.size());
+        for (String k : list) {
+            assertNotEquals("bar", k);
+        }
+    }
+
     @Test
     public void createMap() throws Exception {
         HighAvailableDataSource highAvailableDataSource = new HighAvailableDataSource();
@@ -19,4 +37,21 @@ public class DataSourceCreatorTest {
         assertNotNull(map.get("bar"));
     }
 
+    @Test
+    public void createMapWithPrefix() throws Exception {
+        HighAvailableDataSource highAvailableDataSource = new HighAvailableDataSource();
+        String file = "/com/alibaba/druid/pool/ha/ha-with-prefix-datasource.properties";
+        DataSourceCreator creator = new DataSourceCreator(file, "prefix1");
+        Map<String, DataSource> map = creator.createMap(highAvailableDataSource);
+        assertEquals(1, map.size());
+        assertNotNull(map.get("prefix1.foo"));
+        assertNull(map.get("prefix2.foo"));
+
+        creator = new DataSourceCreator(file, "prefix2");
+        map = creator.createMap(highAvailableDataSource);
+        assertEquals(1, map.size());
+        assertNull(map.get("prefix1.foo"));
+        assertNotNull(map.get("prefix2.foo"));
+    }
+
 }

src/test/java/com/alibaba/druid/pool/ha/selector/BaseRandomDataSourceSelectorTest.java

@@ -0,0 +1,31 @@
+package com.alibaba.druid.pool.ha.selector;
+
+import com.alibaba.druid.pool.ha.HighAvailableDataSource;
+import com.alibaba.druid.pool.ha.MockDataSource;
+import org.junit.After;
+import org.junit.Before;
+
+import javax.sql.DataSource;
+import java.util.HashMap;
+import java.util.Map;
+
+public class BaseRandomDataSourceSelectorTest {
+    protected Map<String, DataSource> dataSourceMap;
+    protected HighAvailableDataSource dataSource;
+
+    @Before
+    public void setUp() {
+        dataSourceMap = new HashMap<String, DataSource>();
+        for (int i = 0; i < 10; i++) {
+            dataSourceMap.put(Integer.toString(i), new MockDataSource(Integer.toString(i)));
+        }
+        dataSource = new HighAvailableDataSource();
+        dataSource.setDataSourceMap(dataSourceMap);
+    }
+
+    @After
+    public void tearDown() {
+        dataSourceMap = null;
+        dataSource = null;
+    }
+}

src/test/java/com/alibaba/druid/pool/ha/selector/RandomDataSourceSelectorTest.java

@@ -1,39 +1,14 @@
 package com.alibaba.druid.pool.ha.selector;
 
-import com.alibaba.druid.pool.ha.HighAvailableDataSource;
 import com.alibaba.druid.pool.ha.MockDataSource;
-import org.junit.After;
-import org.junit.Before;
 import org.junit.Test;
 
-import javax.sql.DataSource;
-import java.util.HashMap;
-import java.util.Map;
-
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
-public class RandomDataSourceSelectorTest {
-    private Map<String, DataSource> dataSourceMap;
-    private HighAvailableDataSource dataSource;
-
-    @Before
-    public void setUp() {
-        dataSourceMap = new HashMap<String, DataSource>();
-        for (int i = 0; i < 10; i++) {
-            dataSourceMap.put(Integer.toString(i), new MockDataSource(Integer.toString(i)));
-        }
-        dataSource = new HighAvailableDataSource();
-        dataSource.setDataSourceMap(dataSourceMap);
-    }
-
-    @After
-    public void tearDown() {
-        dataSourceMap = null;
-        dataSource = null;
-    }
-
+public class RandomDataSourceSelectorTest extends BaseRandomDataSourceSelectorTest {
     @Test
-    public void testRandomGet() throws Exception {
+    public void testRandomGet() {
         RandomDataSourceSelector selector = new RandomDataSourceSelector(dataSource);
         int[] count = new int[10];
 
@@ -48,8 +23,26 @@ public class RandomDataSourceSelectorTest {
     }
 
     @Test
-    public void testOneDataSourceFail() {
+    public void testCreateSelectorWithProperties() {
+        String props = "druid.ha.random.checkingIntervalSeconds=60;";
+        props += "druid.ha.random.recoveryIntervalSeconds=120;";
+        props += "druid.ha.random.validationSleepSeconds=10;";
+        props += "druid.ha.random.blacklistThreshold=5;";
+        dataSource.setConnectionProperties(props);
 
+        RandomDataSourceSelector selector = new RandomDataSourceSelector(dataSource);
+        selector.init();
+        assertEquals(60, selector.getCheckingIntervalSeconds());
+        assertEquals(60, selector.getValidateThread().getCheckingIntervalSeconds());
+
+        assertEquals(120, selector.getRecoveryIntervalSeconds());
+        assertEquals(120, selector.getRecoverThread().getSleepSeconds());
+
+        assertEquals(10, selector.getValidationSleepSeconds());
+        assertEquals(10, selector.getValidateThread().getValidationSleepSeconds());
+        assertEquals(10, selector.getRecoverThread().getValidationSleepSeconds());
+
+        assertEquals(5, selector.getBlacklistThreshold());
+        assertEquals(5, selector.getValidateThread().getBlacklistThreshold());
     }
-
-}
+}

src/test/java/com/alibaba/druid/pool/ha/selector/RandomDataSourceSelectorWithValidationTest.java

@@ -30,17 +30,17 @@ public class RandomDataSourceSelectorWithValidationTest {
 
     @Test
     public void testOneDataSourceFailAndRecover() throws Exception {
-        ((RandomDataSourceSelector) highAvailableDataSource.getDataSourceSelector()).getValidateThread().setSleepSeconds(3);
-        ((RandomDataSourceSelector) highAvailableDataSource.getDataSourceSelector()).getRecoverThread().setSleepSeconds(3);
-
-        Thread.sleep(30 * 1000);
+        RandomDataSourceSelector selector = ((RandomDataSourceSelector) highAvailableDataSource.getDataSourceSelector());
+        selector.getValidateThread().setCheckingIntervalSeconds(3);
+        selector.getRecoverThread().setSleepSeconds(3);
+        selector.init();
 
         DruidDataSource dataSource = (DruidDataSource) highAvailableDataSource.getDataSourceMap().get("foo");
         dataSource.setValidationQuery("select xxx from yyy");
         Thread.sleep(10 * 1000);
         assertTrue(dataSource.isTestOnReturn());
         for (int i = 0; i < 100; i++) {
-            assertNotEquals(dataSource, highAvailableDataSource.getDataSourceSelector().get());
+            assertNotEquals(dataSource, selector.get());
         }
 
         dataSource.setValidationQuery(null);
@@ -48,7 +48,7 @@ public class RandomDataSourceSelectorWithValidationTest {
         assertFalse(dataSource.isTestOnReturn());
         int count = 0;
         for (int i = 0; i < 100; i++) {
-            if (dataSource == highAvailableDataSource.getDataSourceSelector().get()) {
+            if (dataSource == selector.get()) {
                 count++;
             }
         }
@@ -57,23 +57,23 @@ public class RandomDataSourceSelectorWithValidationTest {
 
     @Test
     public void testAllDataSourceFail() throws Exception {
-        ((RandomDataSourceSelector) highAvailableDataSource.getDataSourceSelector()).getValidateThread().setSleepSeconds(3);
-        ((RandomDataSourceSelector) highAvailableDataSource.getDataSourceSelector()).getRecoverThread().setSleepSeconds(3);
-
-        Thread.sleep(30 * 1000);
+        RandomDataSourceSelector selector = (RandomDataSourceSelector) highAvailableDataSource.getDataSourceSelector();
+        selector.setCheckingIntervalSeconds(3);
+        selector.setRecoveryIntervalSeconds(3);
+        selector.init();
 
         DruidDataSource foo = (DruidDataSource) highAvailableDataSource.getDataSourceMap().get("foo");
         DruidDataSource bar = (DruidDataSource) highAvailableDataSource.getDataSourceMap().get("bar");
         foo.setValidationQuery("select xxx from yyy");
         bar.setValidationQuery("select xxx from yyy");
 
-        Thread.sleep(10 * 1000);
+        Thread.sleep(6 * 1000);
         assertTrue(foo.isTestOnReturn());
         assertTrue(bar.isTestOnReturn());
 
         int[] count = new int[2];
         for (int i = 0; i < 100; i++) {
-            DataSource dataSource = highAvailableDataSource.getDataSourceSelector().get();
+            DataSource dataSource = selector.get();
             if (foo == dataSource) {
                 count[0]++;
             } else if (bar == dataSource) {

src/test/java/com/alibaba/druid/pool/ha/selector/StickyRandomDataSourceSelectorTest.java

@@ -0,0 +1,51 @@
+package com.alibaba.druid.pool.ha.selector;
+
+import com.alibaba.druid.pool.ha.MockDataSource;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertTrue;
+
+public class StickyRandomDataSourceSelectorTest extends BaseRandomDataSourceSelectorTest {
+    @Test
+    public void testGetSameDataSourceInFiveSeconds() throws InterruptedException {
+        StickyRandomDataSourceSelector selector = new StickyRandomDataSourceSelector(dataSource);
+        int lastHashCode = selector.get().hashCode();
+        for (int i = 0; i < 4; i++) {
+            assertEquals(lastHashCode, selector.get().hashCode());
+            Thread.sleep(1000);
+        }
+    }
+
+    @Test
+    public void testGetDifferentDataSource() throws InterruptedException {
+        StickyRandomDataSourceSelector selector = new StickyRandomDataSourceSelector(dataSource);
+        selector.setExpireSeconds(1);
+        int lastHashCode = selector.get().hashCode();
+        boolean hasDifferentDataSource = false;
+        for (int i = 0; i < 20; i++) {
+            hasDifferentDataSource = selector.get().hashCode() != lastHashCode;
+            Thread.sleep(500);
+        }
+        assertTrue(hasDifferentDataSource);
+    }
+
+    @Test
+    public void testIgnoreForbiddenDataSource() throws InterruptedException {
+        MockDataSource normal = new MockDataSource("Normal");
+        MockDataSource forbidden = new MockDataSource("Forbidden");
+        dataSourceMap.put("N", normal);
+        dataSourceMap.put("F", forbidden);
+        dataSource.setDataSourceMap(dataSourceMap);
+
+        StickyRandomDataSourceSelector selector = new StickyRandomDataSourceSelector(dataSource);
+        selector.setExpireSeconds(1);
+        selector.getBlacklist().add(forbidden);
+
+        for (int i = 0; i < 20; i++) {
+            assertNotEquals(forbidden, selector.get());
+            Thread.sleep(500);
+        }
+    }
+}

src/test/resources/com/alibaba/druid/pool/ha/ha-with-prefix-datasource.properties

@@ -0,0 +1,4 @@
+prefix1.foo.url=jdbc:derby:memory:foo1;create=true
+prefix2.foo.url=jdbc:derby:memory:foo2;create=true
+foo.url=jdbc:derby:memory:foo3;create=true
+bar=jdbc:derby:memory:bar;create=true