Fail-over PG server in connection string - syntax ?

Hi all.

We have 2 datacenters in diferent locations with public IP addresses each
from different subnets. We would like to use Posgtres JDBC driver fail-over
capability to switch over java client to secondary datacenter if the first
one is unavailable. We need only basic functionality. We cannot use
pgpool-II or something similar at the server side because all these type of
softwares use one virtual IP address which in many cases is from one subnet.

There should be fail-over capability available in the JDBC version 9.2-1000
according to changelog:
http://jdbc.postgresql.org/changes.html#version_9.2-1000

The documentation doesn't mention how to build fail-over connection string
at all. I've found in following mailing list thread mentioning the structure
of the connection string:

http://postgresql.1045698.n5.nabble.com/Re-Failover-Datasource-td4496411.htm
l#a5736270

I tried fail-over by using the version 9.2-1002 in the following example.

I tried to build easy test java script according to this site:
http://www.dotnetfunda.com/Blogs/Niladri.Biswas/3743/connect-to-postgresql-f
rom-java-using-jdbc-driver

The java file then looks like this.

import java.sql.*;

public class JavaPostgreSQLConnectivityTest

{

public static void main(String[] args)

{

String connectionString =
"jdbc:postgresql://pgsqldc1:5432/test,pgsqldc2:5432/test";

String userName = "postgres";

String password = "postgres";

try

{

Class.forName("org.postgresql.Driver"); //specify the JDBC
driver for PostgreSQL

Connection conn = DriverManager.getConnection(connectionString,
userName, password);

System.out.println("Connection properly established");

Statement st = conn.createStatement();

ResultSet rs =
st.executeQuery("SELECT * FROM mytable ORDER BY created DESC LIMIT 5");

while
(rs.next()) {

System.out.print("Column 1 returned ");

System.out.println(rs.getString(1));

}

rs.close();

st.close();

}

catch (Exception e)

{

e.printStackTrace();

}

}

}

When I ran the java compiled class I got this.

D:\temp\Scripts>java -cp postgresql-9.2-1003.jdbc4.jar;
JavaPostgreSQLConnectivityTest

org.postgresql.util.PSQLException: FATAL: database "test,pgsqldc2:5432/test"
does not exist

at
org.postgresql.core.v3.ConnectionFactoryImpl.readStartupMessages(ConnectionF
actoryImpl.java:572)

at
org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFa
ctoryImpl.java:177)

at
org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:
64)

at
org.postgresql.jdbc2.AbstractJdbc2Connection.<init>(AbstractJdbc2Connection.
java:136)

at
org.postgresql.jdbc3.AbstractJdbc3Connection.<init>(AbstractJdbc3Connection.
java:29)

at
org.postgresql.jdbc3g.AbstractJdbc3gConnection.<init>(AbstractJdbc3gConnecti
on.java:21)

at
org.postgresql.jdbc4.AbstractJdbc4Connection.<init>(AbstractJdbc4Connection.
java:31)

at
org.postgresql.jdbc4.Jdbc4Connection.<init>(Jdbc4Connection.java:24)

at org.postgresql.Driver.makeConnection(Driver.java:393)

at org.postgresql.Driver.connect(Driver.java:267)

at java.sql.DriverManager.getConnection(Unknown Source)

at java.sql.DriverManager.getConnection(Unknown Source)

at
JavaPostgreSQLConnectivityTest.main(JavaPostgreSQLConnectivityTest.java:15)

What is the correct syntax for building connection string? Should the
fail-over within postgres-jdbc driver work?

Best regards,

Michal Mistina