I am surprised this was not answered correct yet. I am in the same bucket as you and here is the problem. A quick look at the code and you find the answer. The BaseDataSource class (from which PGSimpleDataSource inherits) does NOT support failover addresses. The underlying driver used to parse the URL does it correctly: it returns url1,url2,url3 for URL and port1,port2,port3 for ports. However, the datasource interprets this as a single address so it tries to convert the "port1,port2,port3" string to an Integer....and it crashes. -- Sent from: http://www.postgresql-archive.org/PostgreSQL-general-f1843780.html