Thanks Chesnay for update. On Tue, Sep 13, 2016 at 12:13 AM, Chesnay Schepler <ches...@apache.org> wrote:
> Hello, > > the JDBC Sink completely ignores the taskNumber and parallelism. > > Regards, > Chesnay > > > On 12.09.2016 08:41, Swapnil Chougule wrote: > > Hi Team, > > I want to know how tasknumber & numtasks help in opening db connection in > Flink JDBC JDBCOutputFormat Open. I checked with docs where it says: > taskNumber - The number of the parallel instance. numTasks - The number > of parallel tasks. But couldn't get clear idea among parallel instance & > parallel tasks. How do they contribute in concurrency with JDBC Source/Sink? > > I also checked with code but couldn't drill down further > > /** > * Connects to the target database and initializes the prepared statement. > * > * @param taskNumber The number of the parallel instance. > * @throws IOException Thrown, if the output could not be opened due to an > * I/O problem. > */ > @Override > public void open(int taskNumber, int numTasks) throws IOException { > try { > establishConnection(); > upload = dbConn.prepareStatement(query); > } catch (SQLException sqe) { > throw new IllegalArgumentException("open() failed.", sqe); > } catch (ClassNotFoundException cnfe) { > throw new IllegalArgumentException("JDBC driver class not found.", cnfe); > } > } > > private void establishConnection() throws SQLException, > ClassNotFoundException { > Class.forName(drivername); > if (username == null) { > dbConn = DriverManager.getConnection(dbURL); > } else { > dbConn = DriverManager.getConnection(dbURL, username, password); > } > } > > Thanks, > Swapnil > > > >