支持HA

git-svn-id: http://code.alibabatech.com/svn/druid/trunk@469 b9813039-fb51-4c41-a8b9-e21c2acb5095

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

@@ -6,22 +6,15 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
-import java.util.concurrent.atomic.AtomicInteger;
 
 import javax.sql.DataSource;
 
-import com.alibaba.druid.logging.Log;
-import com.alibaba.druid.logging.LogFactory;
 import com.alibaba.druid.pool.DruidDataSource;
 import com.alibaba.druid.pool.ha.balance.Balancer;
 import com.alibaba.druid.pool.ha.balance.RoundRobinBlancer;
 
 public class HADataSource extends MultiDataSource implements DataSource {
 
-    private final static Log              LOG                     = LogFactory.getLog(HADataSource.class);
-
-    private final AtomicInteger           indexErrorCount         = new AtomicInteger();
-
     protected ArrayList<DruidDataSource>  dataSources             = new ArrayList<DruidDataSource>();
     protected final List<DruidDataSource> notAvailableDatasources = new CopyOnWriteArrayList<DruidDataSource>();
 
@@ -52,71 +45,17 @@ public class HADataSource extends MultiDataSource implements DataSource {
         this.balancer = balancer;
     }
 
-    protected int indexFor(MultiDataSourceConnection connection, String sql) throws SQLException {
-        return balancer.indexFor(connection, sql);
+    public Connection getConnectionInternal(MultiDataSourceConnection connection, String sql) throws SQLException {
+        return this.balancer.getConnection(connection, sql);
     }
 
-    public Connection getConnectionInternal(MultiDataSourceConnection multiDataSourceConnection, String sql) throws SQLException {
-
-        int tryCount = 0;
-
-        for (;;) {
-            int size = dataSources.size();
-
-            if (size == 0) {
-                throw new SQLException("can not get connection, no availabe datasources");
-            }
-
-            int index = indexFor(multiDataSourceConnection, sql);
-
-            DruidDataSource dataSource = null;
-
-            try {
-                // 处理并发时的错误
-                dataSource = dataSources.get(index);
-            } catch (Exception ex) {
-                indexErrorCount.incrementAndGet();
-                if (LOG.isDebugEnabled()) {
-                    LOG.debug("getDataSource error, index : " + index, ex);
-                }
-                continue;
-            }
-
-            assert dataSource != null;
-
-            if (!dataSource.isEnable()) {
-                handleNotAwailableDatasource(dataSource);
-                continue;
-            }
-
-            Connection conn = null;
-
-            try {
-                tryCount++;
-                conn = dataSource.getConnection();
-            } catch (SQLException ex) {
-                LOG.error("getConnection error", ex);
-
-                if (tryCount >= size) {
-                    throw ex;
-                }
-
-                continue;
-            }
-
-            return conn;
-        }
-    }
-
-    void handleNotAwailableDatasource(DruidDataSource dataSource) {
+    public void handleNotAwailableDatasource(DruidDataSource dataSource) {
         boolean removed = dataSources.remove(dataSource);
         if (removed) {
             notAvailableDatasources.add(dataSource);
         }
     }
 
-    public long getIndexErrorCount() {
-        return indexErrorCount.get();
-    }
+
 
 }

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

@@ -41,4 +41,6 @@ public abstract class MultiDataSource extends DataSourceAdapter {
     public abstract Connection getConnection() throws SQLException;
 
     public abstract Connection getConnectionInternal(MultiDataSourceConnection conn, String sql) throws SQLException;
+    
+    public abstract void handleNotAwailableDatasource(DruidDataSource dataSource);
 }

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

@@ -51,7 +51,7 @@ public class MultiDataSourceConnection extends WrapperAdapter implements Connect
         this.haDataSource = haDataSource;
         this.id = id;
     }
-
+    
     public void checkConnection(String sql) throws SQLException {
         if (conn == null) {
             conn = haDataSource.getConnectionInternal(this, sql);

src/main/java/com/alibaba/druid/pool/ha/balance/Balancer.java

@@ -1,9 +1,10 @@
 package com.alibaba.druid.pool.ha.balance;
 
+import java.sql.Connection;
 import java.sql.SQLException;
 
 import com.alibaba.druid.pool.ha.MultiDataSourceConnection;
 
 public interface Balancer {
-    int indexFor(MultiDataSourceConnection connection, String sql) throws SQLException;
+    Connection getConnection(MultiDataSourceConnection connectionProxy, String sql) throws SQLException;
 }

src/main/java/com/alibaba/druid/pool/ha/balance/RoundRobinBlancer.java

@@ -1,20 +1,81 @@
 package com.alibaba.druid.pool.ha.balance;
 
+import java.sql.Connection;
 import java.sql.SQLException;
+import java.util.concurrent.atomic.AtomicInteger;
 
+import com.alibaba.druid.logging.Log;
+import com.alibaba.druid.logging.LogFactory;
+import com.alibaba.druid.pool.DruidDataSource;
 import com.alibaba.druid.pool.ha.MultiDataSource;
 import com.alibaba.druid.pool.ha.MultiDataSourceConnection;
 
 public class RoundRobinBlancer implements Balancer {
 
-    @Override
-    public int indexFor(MultiDataSourceConnection connection, String sql) throws SQLException {
-        MultiDataSource dataSource = connection.getHaDataSource();
+    private final static Log    LOG             = LogFactory.getLog(RoundRobinBlancer.class);
 
-        int size = dataSource.getDataSources().size();
-        long connectionId = (int) connection.getId();
+    private final AtomicInteger indexErrorCount = new AtomicInteger();
+
+    public RoundRobinBlancer(){
 
-        return (int) (connectionId % size);
     }
 
+    @Override
+    public Connection getConnection(MultiDataSourceConnection connectionProxy, String sql) throws SQLException {
+        MultiDataSource multiDataSource = connectionProxy.getHaDataSource();
+
+        int tryCount = 0;
+
+        for (;;) {
+            int size = multiDataSource.getDataSources().size();
+            long connectionId = (int) connectionProxy.getId();
+
+            if (size == 0) {
+                throw new SQLException("can not get connection, no availabe datasources");
+            }
+
+            int index = (int) (connectionId % size);
+
+            DruidDataSource dataSource = null;
+
+            try {
+                // 处理并发时的错误
+                dataSource = multiDataSource.getDataSources().get(index);
+            } catch (Exception ex) {
+                indexErrorCount.incrementAndGet();
+                if (LOG.isDebugEnabled()) {
+                    LOG.debug("getDataSource error, index : " + index, ex);
+                }
+                continue;
+            }
+
+            assert dataSource != null;
+
+            if (!dataSource.isEnable()) {
+                multiDataSource.handleNotAwailableDatasource(dataSource);
+                continue;
+            }
+
+            Connection conn = null;
+
+            try {
+                tryCount++;
+                conn = dataSource.getConnection();
+            } catch (SQLException ex) {
+                LOG.error("getConnection error", ex);
+
+                if (tryCount >= size) {
+                    throw ex;
+                }
+
+                continue;
+            }
+
+            return conn;
+        }
+    }
+
+    public long getIndexErrorCount() {
+        return indexErrorCount.get();
+    }
 }

src/main/java/com/alibaba/druid/pool/ha/balance/SimpleBalancer.java

@@ -0,0 +1,57 @@
+package com.alibaba.druid.pool.ha.balance;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+
+import com.alibaba.druid.pool.DruidDataSource;
+import com.alibaba.druid.pool.ha.MultiDataSource;
+import com.alibaba.druid.pool.ha.MultiDataSourceConnection;
+
+public class SimpleBalancer implements Balancer {
+
+    private int maxActive = 8;
+
+    public int getMaxActive() {
+        return maxActive;
+    }
+
+    public void setMaxActive(int maxActive) {
+        this.maxActive = maxActive;
+    }
+
+    @Override
+    public Connection getConnection(MultiDataSourceConnection connectionProxy, String sql) throws SQLException {
+        MultiDataSource multiDataSource = connectionProxy.getHaDataSource();
+
+        Object[] array = multiDataSource.getDataSources().toArray();
+
+        DruidDataSource minDataSource = null;
+        int min = 0;
+        for (Object item : array) {
+            DruidDataSource dataSource = (DruidDataSource) item;
+
+            if (!dataSource.isEnable()) {
+                continue;
+            }
+
+            int activeCount = dataSource.getActiveCount();
+
+            if (minDataSource == null || activeCount < min) {
+                minDataSource = dataSource;
+                min = activeCount;
+            }
+
+            if (activeCount >= maxActive) {
+                continue;
+            }
+
+            return dataSource.getConnection();
+        }
+
+        if (minDataSource != null) {
+            return minDataSource.getConnection();
+        }
+
+        throw new SQLException("can not get connection, no availabe datasources");
+    }
+}