Tracing JDBC connection creation

JDBC open connection and resultSet.next() is not logging in span

	Context initContext = new InitialContext();
	Context envContext = (Context)initContext.lookup("java:/comp/env");
	DataSource ds = (DataSource)envContext.lookup(dsName);
	conn=ds.getConnection();
	stmt=conn.createStatement();
	rset=stmt.executeQuery("select a.* from editor.cw_news a");
	while (rset.next()){
		out.print("<br>"+ rset.getString("newstitle"));
	}

Transaction show just the select span and there is no logging for open connection time and resultSet retrieve time

[matthiaswelz]

I have just created a really simple plugin to instrument DataSource#getConnection like @CoderLan0668 and attached it to one of my real-world applications. After running a very simple performance test, I can see that in some traces, the getConnection calls account for over 50% of the transaction time.

Of course, my example might not be representative about the elastic community. But I definitely wanted to voice my support for this feature - I definitely see value in this instrumentation and would welcome to see something in the elastic-apm-agent in the future out-of-the box.

[eyalkoren]

Without looking too much into this, it seems that java.sql.Driver#connect would be a native candidate for that.

NOTE: by instrumenting java.sql.Driver#connect we may eliminate the possibly-active java.sql.Connection#getMetaData usage, getting the URL from the first argument, the user from the second (java.util.Properties) argument and the vendor based on the Driver class name.