Bryan,

Took a look at the demo. Nice presentation of the data.

Depending on usage, the D3 licensing would potentially be a roadblock. I'll be completely up front, licensing is a real cost.

Maybe a better approach if I wanted to deliver D3 info would be to code an extract program, or an odbc, or rest api to

pull the data into a postgres or other (less licensed) db and expose that to the world.

I'm a lover of all thing IT, so I will for sure snoop at your sample code. I'm a relatively new Java coder, so it will be good to

see some techniques.

Very best,

Bret

Hi Bret,

Yep, licencing is an issue with all 'non-free' databases. If most of your queries are pretty fast, you don't really need too many DBMS connections. In my sample code, I didn't put a retry (e.g. something like a Thread.sleep(1000)), which means you'd never "run out" of connections, some would just take a little longer to return a result. (I didn't do that because I was specifically wanting to check connection exhaustion).

When I've used Postgresql as the backend, the connection pooling I use normally would have 10 connections.

    DataSource getPool() {

        PoolProperties p = new PoolProperties();
        p.setUrl("jdbc:postgresql://localhost/" + ServerConstants.DBMS);
        p.setDriverClassName("org.postgresql.Driver");
        p.setUsername("XXXXXX");
        p.setPassword("XXXXX");
        p.setJmxEnabled(true);
        p.setTestWhileIdle(false);
        p.setTestOnBorrow(true);
        p.setValidationQuery("SELECT 1");
        p.setTestOnReturn(false);
        p.setValidationInterval(30000);
        p.setTimeBetweenEvictionRunsMillis(30000);
        p.setMaxActive(100);
        p.setInitialSize(10);
        p.setMaxWait(10000);
        p.setRemoveAbandonedTimeout(60);
        p.setMinEvictableIdleTimeMillis(30000);
        p.setMinIdle(10);
        p.setLogAbandoned(true);
        p.setRemoveAbandoned(true);
        p.setJdbcInterceptors("org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer");
        DataSource datasource = new DataSource();
        datasource.setPoolProperties(p);
        return datasource;
    }

I think if Enterprise Licencing worked on Linux, a 5 user licence could probably handle a reasonable load.

Bryan