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From TomohitoNakayama <tomon...@basil.ocn.ne.jp>
Subject Re: [jira] Commented: (DERBY-550) BLOB : java.lang.OutOfMemoryError with network JDBC driver (org.apache.derby.jdbc.ClientDriver)
Date Wed, 12 Jul 2006 12:29:49 GMT
Hello.

Regretfully I'm not sure whether I can fix this issue until 10.2 release
because it is not clear where memory is used wastefully and
how we can judge whether we could solve this issue.

//Even if OutOfMemoryError happens, it would be not a problem in an 
environment with very small amount of memory ....
//I think criterion to judge resolve of this issue is needed ...

However, I think throw Exception judging from amount of spare memory 
would be too cunning behavor ......

Now ... I'm in dilemma.....
At least, I won't veto it.

Best regards.


Andreas Korneliussen (JIRA) wrote:

>    [ http://issues.apache.org/jira/browse/DERBY-550?page=comments#action_12420591 ] 
>
>Andreas Korneliussen commented on DERBY-550:
>--------------------------------------------
>
>Unless the streaming could be fixed for 10.2 so that we avoid OutOfMemoryError on the
receiver side, I would propose the following:
>
>We know the size of the LOB, and can check if it can go into memory (using the Runtime
class). If it cannot go into memory, we can throw an SQLException, instead of consuming all
memory in the VM until we get OutOfMemoryError.
>
>By using this approach, we achieve the following:
>* Side-effects on other connections in the VM: Although it is the LOB which is taking
almost all the memory in the VM, the OutOfMemoryError may be thrown in another thread in the
VM, causing side-effects on other connections or on the application itself.
>* Currently, if the Network server goes out of memory when streaming data, the DRDAConnThread
will stop. This causes hangs in the user applications. 
>
>If the streaming is fixed, there is not need to do this. Does anyone plan to fix the streaming
issues for 10.2 ? If not, I will make a couple of JIRA issues to do the work of avoiding OutOfMemoryError
by checking size before allocating the byte arrays.
>
>
>  
>
>>BLOB : java.lang.OutOfMemoryError with network JDBC driver (org.apache.derby.jdbc.ClientDriver)
>>-----------------------------------------------------------------------------------------------
>>
>>         Key: DERBY-550
>>         URL: http://issues.apache.org/jira/browse/DERBY-550
>>     Project: Derby
>>        Type: Bug
>>    
>>
>
>  
>
>>  Components: JDBC, Network Server
>>    Versions: 10.1.1.0
>> Environment: Any environment.
>>    Reporter: Grégoire Dubois
>>    Assignee: Tomohito Nakayama
>> Attachments: BlobOutOfMem.java
>>
>>Using the org.apache.derby.jdbc.ClientDriver driver to access the
>>Derby database through network, the driver is writting all the file into memory (RAM)
before sending
>>it to the database.
>>Writting small files (smaller than 5Mo) into the database works fine,
>>but it is impossible to write big files (40Mo for example, or more), without getting
the
>>exception java.lang.OutOfMemoryError.
>>The org.apache.derby.jdbc.EmbeddedDriver doesn't have this problem.
>>Here follows some code that creates a database, a table, and trys to write a BLOB.
2 parameters are to be changed for the code to work for you : DERBY_DBMS_PATH and FILE
>>import NetNoLedge.Configuration.Configs;
>>import org.apache.derby.drda.NetworkServerControl;
>>import java.net.InetAddress;
>>import java.io.*;
>>import java.sql.*;
>>/**
>> *
>> * @author  greg
>> */
>>public class DerbyServer_JDBC_BLOB_test {
>>    
>>    // The unique instance of DerbyServer in the application.
>>    private static DerbyServer_JDBC_BLOB_test derbyServer;
>>    
>>    private NetworkServerControl server;
>>    
>>    private static final String DERBY_JDBC_DRIVER = "org.apache.derby.jdbc.ClientDriver";
>>    private static final String DERBY_DATABASE_NAME = "Test";
>>    
>>    // ###############################################################
>>    // ############### SET HERE THE EXISTING PATH YOU WANT ################
>>    // ###############################################################
>>    private static final String DERBY_DBMS_PATH =  "/home/greg/DatabaseTest";
>>    // ###############################################################
>>    // ###############################################################
>>    
>>    
>>    private static int derbyPort = 9157;
>>    private static String userName = "user";
>>    private static String userPassword = "password";
>>    
>>    // ###################################################################################
>>    // ############# DEFINE HERE THE PATH TO THE FILE YOU WANT TO WRITE INTO THE DATABASE
###########
>>    // ############# TRY A 100kb-3Mb FILE, AND AFTER A 40Mb OR BIGGER FILE #########################
>>    // ###################################################################################
>>    private static final File FILE = new File("/home/greg/01.jpg");
>>    // ###################################################################################
>>    // ###################################################################################
>>    
>>    /**
>>     * <p>Used to test the server.
>>     */
>>    public static void main(String args[]) {
>>        try {
>>            DerbyServer_JDBC_BLOB_test.launchServer();
>>            DerbyServer_JDBC_BLOB_test server = getUniqueInstance();
>>            server.start();
>>            System.out.println("Server started");
>>        
>>            // After the server has been started, launch a first connection to the
database to
>>            // 1) Create the database if it doesn't exist already,
>>            // 2) Create the tables if they don't exist already.            
>>            Class.forName(DERBY_JDBC_DRIVER).newInstance();
>>            Connection connection = DriverManager.getConnection ("jdbc:derby://localhost:"+derbyPort+"/"+DERBY_DATABASE_NAME+";create=true",
userName, userPassword);
>>            System.out.println("Network JDBC connection to Derby succeded. Database
created if not created already.");
>>            
>>            Statement statement = connection.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY);
>>            Statement statement2;
>>            // Create the table "file" if it doesn't already exist.
>>            String [] tableNames={"file"};
>>            boolean exist;
>>            String currentTable;
>>            ResultSet result = statement.executeQuery("SELECT TABLENAME FROM SYS.SYSTABLES");
>>            for (int i=0;i<tableNames.length;i++) {
>>                exist=false;
>>                while (result.next()){
>>                    if (tableNames[i].equalsIgnoreCase(result.getString(1)))
>>                        exist=true;
>>                }
>>            
>>                if (!exist) {
>>                    statement2 = connection.createStatement();
>>                    statement2.execute("CREATE TABLE file (" +
>>                    "file BLOB(2G) NOT NULL)");
>>                    connection.commit();
>>                }
>>                result.beforeFirst();
>>            }
>>            System.out.println("Table file created if not created already");
>>            
>>            System.out.println("File insertion into BLOB");
>>            FileInputStream inputStream = new FileInputStream(FILE);
>>            PreparedStatement   preparedStatement = connection.prepareStatement("INSERT
INTO file(file) VALUES (?)");
>>            preparedStatement.setBinaryStream(1,inputStream,(int) FILE.length());
>>            preparedStatement .execute();
>>            connection.commit();
>>            System.out.println("File inserted into BLOB");
>>        }
>>        catch (Exception e) {
>>            e.printStackTrace();
>>        }
>>    }
>>    
>>    /** Creates a new instance of MckoiServer
>>     * Password is used at the database creation. It will be the database password
once created.
>>     */    
>>    private DerbyServer_JDBC_BLOB_test() throws Exception {
>>        System.setProperty("derby.system.home", DERBY_DBMS_PATH);
>>        
>>        // Set the server to request an authentification.
>>        System.setProperty("derby.authentication.provider", "BUILTIN");
>>        System.setProperty("derby.connection.requireAuthentication", "true");
>>        
>>        // Create a user that can connect to Derby.
>>        System.setProperty("derby.user."+userName, userPassword);
>>        
>>        // Set Derby to grant full access to the created user (to all the databases).
>>        System.setProperty("derby.database.fullAccessUsers", userName);
>>        
>>        //System.setProperty("derby.system.bootAll", "true");
>>        
>>        // See if the 9157 port is already taken.
>>        // Change it if necessary.
>>        boolean isPortFree = false;
>>        while ( !isPortFree ) {
>>            try {
>>                java.net.ServerSocket serverTest = new java.net.ServerSocket(derbyPort);
>>                serverTest.close();
>>                serverTest = null;
>>                
>>                isPortFree = true;
>>            }
>>            catch (Exception e) {
>>                System.out.println("Port already in use : "+derbyPort);
>>                derbyPort++;
>>                System.out.println("Try with port "+derbyPort);
>>            }
>>        }     
>>        
>>        server = new NetworkServerControl(InetAddress.getByName("localhost"),derbyPort);
>>    }
>>    
>>    public static void launchServer() throws Exception {
>>        derbyServer = new DerbyServer_JDBC_BLOB_test();
>>    }
>>    
>>    public static DerbyServer_JDBC_BLOB_test getUniqueInstance() {
>>        return derbyServer;
>>    }
>>    
>>    /**
>>     * <p>Start the server.
>>     */
>>    public void start() {
>>        try {
>>            server.start(null);
>>        }
>>        catch (Exception e) {
>>            e.printStackTrace(System.err);
>>        }
>>    }
>>    
>>    /**
>>     * <p>Stop the server.
>>     */
>>    public void stop() {
>>        try {
>>            server.shutdown();
>>        }
>>        catch (Exception e) {
>>            e.printStackTrace(System.err);
>>        }
>>    }
>>}
>>    
>>
>
>  
>

-- 
/*

        Tomohito Nakayama
        tomonaka@basil.ocn.ne.jp
        tomohito@rose.zero.ad.jp
        tmnk@apache.org

        Naka
        http://www5.ocn.ne.jp/~tomohito/TopPage.html

*/ 


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