tomcat jdbc pool timeout not working

Question

I am developing high-load application using tomcat jdbc connection pool and Oracle database. It is very important to ensure my app to have very small DB query timeouts (no longer than 3 seconds) to prevent long-running queries or database slowness from blocking all my application. To simulate long-running queries I have put the DB in QUIESCE state using ALTER SYSTEM QUIESCE RESTRICTED statement.

But it looks like the timeout values have no impact - when i begin to test my application, it hangs...

Here is my jdbc pool configuration:

String connprops = "oracle.net.CONNECT_TIMEOUT=3000;oracle.jdbc.ReadTimeout=3000;"
                    + "oracle.net.READ_TIMEOUT=3000";


            pp.setConnectionProperties(connprops);

            pp.setDriverClassName("oracle.jdbc.OracleDriver");

            pp.setTestOnBorrow(true);
            pp.setTestOnConnect(true);
            pp.setTestOnReturn(true);

            pp.setTestWhileIdle(true);

            pp.setMaxWait(2000);
            pp.setMinEvictableIdleTimeMillis(20000);
            pp.setTimeBetweenEvictionRunsMillis(20000);

            pp.setValidationInterval(3000);
            pp.setValidationQuery("SELECT 1 FROM DUAL");

            pp.setMaxAge(3000);
            pp.setRemoveAbandoned(true);
            pp.setRemoveAbandonedTimeout(3);

            pp.setJdbcInterceptors("org.apache.tomcat.jdbc.pool.interceptor.QueryTimeoutInterceptor(queryTimeout=3)");
            dataSource = new DataSource();
            dataSource.setPoolProperties(pp);

That's how i work with connections (pretty simple):

Connection conn = dataSource.getConnection();
        Statement stmt = null;
        ResultSet rs = null;

        try {
            stmt = conn.createStatement();

            rs = stmt.executeQuery(/*some select query*/);


            if (rs.next()) {

                result = rs.getInt(1);

                /*process the result*/

            }

            rs.close();
            stmt.close();
            conn.close();

        }
        catch(Exception e) {
            logger.error("Exception: " + e.getMessage(), e);
        }finally {
            if (conn != null) {

                    if(rs!=null)
                    rs.close();
                    if(stmt!=null)
                    stmt.close();
                    conn.close();

            }
        }

Any ideas? Thanks in advance!

Answer 1

Try to use this config:

String connprops = "oracle.net.CONNECT_TIMEOUT=\"3000\";oracle.jdbc.ReadTimeout=\"3000\";"
                + "oracle.net.READ_TIMEOUT=\"3000\"";

All non-string values are ignored by java.util.Properties.java :

public String getProperty(String key) {
    Object oval = super.get(key);
    String sval = (oval instanceof String) ? (String)oval : null; // <- !!!!
    return ((sval == null) && (defaults != null)) ? defaults.getProperty(key) : sval;
}

You should probably also use java.sql.Statement's query timeout :

stmt.setQueryTimeout(3); // int seconds