The CreateCluster tool now sets the source database in exclusive mode before…

The CreateCluster tool now sets the source database in exclusive mode before copying data to the new database.

h2/src/main/org/h2/tools/CreateCluster.java

@@ -6,6 +6,7 @@
  */
 package org.h2.tools;
 
+import java.io.OutputStream;
 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.SQLException;
@@ -94,17 +95,17 @@ public class CreateCluster extends Tool {
     }
 
     private void process(String urlSource, String urlTarget, String user, String password, String serverList) throws SQLException {
-        Connection conn = null;
-        Statement stat = null;
+        Connection connSource = null, connTarget = null;
+        Statement statSource = null, statTarget = null;
+        String scriptFile = "backup.sql";
         try {
             org.h2.Driver.load();
-            // use cluster='' so connecting is possible even if the cluster is enabled
-            conn = DriverManager.getConnection(urlSource + ";CLUSTER=''", user, password);
-            conn.close();
+
+            // verify that the database doesn't exist
             boolean exists;
             try {
-                conn = DriverManager.getConnection(urlTarget + ";IFEXISTS=TRUE", user, password);
-                conn.close();
+                connTarget = DriverManager.getConnection(urlTarget + ";IFEXISTS=TRUE", user, password);
+                connTarget.close();
                 exists = true;
             } catch (SQLException e) {
                 // database does not exists - ok
@@ -114,31 +115,45 @@ public class CreateCluster extends Tool {
                 throw new SQLException("Target database must not yet exist. Please delete it first");
             }
 
-            // TODO cluster: need to open the database in exclusive mode,
-            // so that other applications
-            // cannot change the data while it is restoring the second database.
-            // But there is currently no exclusive mode.
+            // use cluster='' so connecting is possible
+            // even if the cluster is enabled
+            connSource = DriverManager.getConnection(urlSource + ";CLUSTER=''", user, password);
+            statSource = connSource.createStatement();
 
-            String scriptFile = "backup.sql";
-            Script sc = new Script();
-            sc.setOut(out);
-            sc.process(urlSource, user, password, scriptFile);
-            RunScript runscript = new RunScript();
-            runscript.setOut(out);
-            runscript.process(urlTarget, user, password, scriptFile, null, false);
-            IOUtils.delete(scriptFile);
+            // enable the exclusive mode, so that other applications
+            // cannot change the data while it is restoring the second database
+            statSource.execute("SET EXCLUSIVE TRUE");
+
+            // backup
+            Script script = new Script();
+            script.setOut(out);
+            OutputStream scriptOut = null;
+            try {
+                scriptOut = IOUtils.openFileOutputStream(scriptFile, false);
+                script.process(connSource, scriptOut);
+            } finally {
+                IOUtils.closeSilently(scriptOut);
+            }
+
+            // restore
+            RunScript runScript = new RunScript();
+            runScript.setOut(out);
+            runScript.process(urlTarget, user, password, scriptFile, null, false);
+
+            connTarget = DriverManager.getConnection(urlTarget, user, password);
+            statTarget = connTarget.createStatement();
 
             // set the cluster to the serverList on both databases
-            conn = DriverManager.getConnection(urlSource, user, password);
-            stat = conn.createStatement();
-            stat.executeUpdate("SET CLUSTER '" + serverList + "'");
-            conn.close();
-            conn = DriverManager.getConnection(urlTarget, user, password);
-            stat = conn.createStatement();
-            stat.executeUpdate("SET CLUSTER '" + serverList + "'");
+            statSource.executeUpdate("SET CLUSTER '" + serverList + "'");
+            statTarget.executeUpdate("SET CLUSTER '" + serverList + "'");
+
+            statSource.execute("SET EXCLUSIVE FALSE");
         } finally {
-            JdbcUtils.closeSilently(conn);
-            JdbcUtils.closeSilently(stat);
+            IOUtils.delete(scriptFile);
+            JdbcUtils.closeSilently(statSource);
+            JdbcUtils.closeSilently(statTarget);
+            JdbcUtils.closeSilently(connSource);
+            JdbcUtils.closeSilently(connTarget);
         }
     }
 

h2/src/main/org/h2/tools/Script.java

@@ -168,10 +168,25 @@ public class Script extends Tool {
      */
     void process(String url, String user, String password, OutputStream o) throws SQLException {
         Connection conn = null;
-        Statement stat = null;
         try {
             org.h2.Driver.load();
             conn = DriverManager.getConnection(url, user, password);
+            process(conn, o);
+        } finally {
+            JdbcUtils.closeSilently(conn);
+        }
+    }
+
+    /**
+     * Backs up a database to a stream. The stream is not closed.
+     * The connection is not closed.
+     *
+     * @param conn the connection
+     * @param o the output stream
+     */
+    void process(Connection conn, OutputStream o) throws SQLException {
+        Statement stat = null;
+        try {
             stat = conn.createStatement();
             PrintWriter writer = new PrintWriter(IOUtils.getWriter(o));
             ResultSet rs = stat.executeQuery("SCRIPT");
@@ -182,7 +197,6 @@ public class Script extends Tool {
             writer.flush();
         } finally {
             JdbcUtils.closeSilently(stat);
-            JdbcUtils.closeSilently(conn);
         }
     }
 

h2/src/test/org/h2/test/unit/TestTools.java

@@ -589,6 +589,7 @@ public class TestTools extends TestBase {
         assertTrue(rs.next());
         assertFalse(rs.next());
         try {
+            // must fail when the database is in use
             Backup.main("-file", fileName, "-dir", baseDir, "-db", "utils");
             fail();
         } catch (SQLException e) {