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Not able to connect oracle Database while using Cluster type HOST

I'm facing the following errors while connecting oracle DB, I'm using spring boot JDBC template to connect to database. The errors are below,
Exception in thread "main" java.lang.Exception: java.sql.SQLRecoverableException: IO Error: The Network Adapter could not establish the connection
at com.falabella.util.OracleDB.main(OracleDB.java:70)
Caused by: java.sql.SQLRecoverableException: IO Error: The Network Adapter could not establish the connection
Caused by: oracle.net.ns.NetException: The Network Adapter could not establish the connection
at oracle.net.nt.ConnStrategy.execute(ConnStrategy.java:392)
Caused by: java.net.UnknownHostException: NODE-01: nodename nor servname provided, or not known
Below are my finding, My database server host having the cluster and it has two nodes, like below,
Cluster (wood.clsuter.com)
| NODE01 (wood-01)
| NODE02 (wood-02)
My connection string is like this, jdbc:oracle:thin:#wood-clsuter.com:1531/service_name
When I'm using the cluster name in the connection string, I'm facing the below error
Caused by: java.net.UnknownHostException: wood-01: nodename nor servname provided, or not known
Whereas if I use any of the node name in the connection string , able to connect Data base without any issue, the working connection string is like below,
jdbc:oracle:thin:#wood-01.com:1531/service_name or
jdbc:oracle:thin:#wood-02.com:1531/service_name
Since I need to use my DB requests as load balancing, I need to use the cluster name instead of slave nodes,
I would like to know the root cause of this issue, such kind of production environment issues,
Could you please help me out with this?

You need to change connect string to:
"jdbc:oracle:thin:#(DESCRIPTION=(FAILOVER=ON)(LOAD_BALANCE=ON)(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=wood-01.com)(PORT = 1531))(ADDRESS = (PROTOCOL = TCP)(HOST = wood-02.com)(PORT = 1531)))(CONNECT_DATA=(SERVICE_NAME =service_name)(FAILOVER_MODE=(TYPE=select)(METHOD=basic))))"

Local and Remote connection pools, Java DBCP

I have the following use-case:
I have a system that needs to use two different connection pools, One is for 'local' database (Meaning a database running on the local machine) and the other one is a 'remote' database. (Meaning a database that is running on a remote different server)
The remote database is a configuration sharing database, while the local one is has different kinds of data.
I've created two classes in order to connect to those datababase:
public class ConnectionPool {
private static BasicDataSource ds = createNewDatasource();
private static BasicDataSource createNewDatasource() {
BasicDataSource ds = new BasicDataSource();
String url = "jdbc:mysql://127.0.0.1:3306/SOME_DB"
ds.setUrl(url);
ds.setUsername(...);
ds.setPassword(...);
return ds;
}
public static Connection getConnection() throws SQLException {
return ds.getConnection();
}
}
The other class looks exactly the same, Only it's called RemoteConnection and the url is changed to:
String url = "jdbc:mysql://<REMOTE_IP>:3306/SOME_DB_2"
Running the above classes, I keep receiving the following message in my logs:
ERROR (RemoteConnection.java:40) - Failed on getConnection
java.sql.SQLException: Cannot create PoolableConnectionFactory (Access denied for user '...'#'<MACHINE_LOCAL_IP>' (using password: YES))
at org.apache.commons.dbcp2.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:2291)
at org.apache.commons.dbcp2.BasicDataSource.createDataSource(BasicDataSource.java:2038)
at org.apache.commons.dbcp2.BasicDataSource.getConnection(BasicDataSource.java:1533)
at Censored.RemoteConnection.getConnection(RemoteConnection.java:59)
...
Caused by: java.sql.SQLException: Access denied for user '...'#'<MACHINE_LOCAL_IP>' (using password: YES)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:965)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3973)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3909)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:873)
at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1710)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1226)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2188)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2219)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2014)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:776)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.GeneratedConstructorAccessor31.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:57)
at java.lang.reflect.Constructor.newInstance(Constructor.java:437)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330)
at org.apache.commons.dbcp2.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:39)
at org.apache.commons.dbcp2.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:256)
at org.apache.commons.dbcp2.BasicDataSource.validateConnectionFactory(BasicDataSource.java:2301)
at org.apache.commons.dbcp2.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:2287)
...
Firstly, The error above is weird. I've never used the machine local IP. So I don't understand where it came from. In addition, It doesn't seems like a privilege problem since I've tried logging into remote database through cli, using:
mysql -u'...' -p'...' -h <REMOTE_IP> SOME_DB_2
And it connected successfully. It smells to me like a JDBC Driver or connection definition problem but I can't seem to find the problematic spot.
Any idea what I'm doing wrong?

I've found the problem. It was an SSL issue.
The user I've used had to connect with SSL certificate.
That's also the reason why I've seen the local machine IP in the error.
A way to check is:
Select * from mysql.user where user='...';
What I've found was that:
ssl_type != ''
So I had to define:
jdbc:mysql://<REMOTE_IP>:3306/SOME_DB_2&useSSL=true
Configure the relevant certificates, and all was well.

Error when accesing MySQL database remotely using public IP

I have a MySQL database. My friend is trying to access it from a different computer using my public IP.
This is the program he used to test the connection:
public class Main {
public static void main(String args[]) {
String url = "jdbc:mysql://IPadresss:3307/javabase";
String username = "bob";
String password = "bob";
Properties properties = new Properties();
properties.setProperty("bob", "bob");
properties.setProperty("bob", "bob");
properties.setProperty("useSSL", "false");
properties.setProperty("autoReconnect", "true");
System.out.println("Connecting database...");
try (Connection connection = DriverManager.getConnection(url, properties)) {
System.out.println("Database connected!");
} catch (SQLException e) {
throw new IllegalStateException("Cannot connect the database!", e);
}
}
}
This is the error my friend, who is the client, gets:
Connecting database...
Exception in thread "main" java.lang.IllegalStateException: Cannot connect the database!
at SQLConnector.Main.main(Main.java:23)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.Util.getInstance(Util.java:408)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:918)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:897)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:886)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:860)
at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2163)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2088)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:806)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:410)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:328)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:208)
at SQLConnector.Main.main(Main.java:20)
Caused by: java.sql.SQLException: Access denied for user ''#'Freinds ip' (using password: NO)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:964)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3970)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3906)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:873)
at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1710)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1226)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2253)
at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2104)
... 13 more
Please help me find out what is wrong with my method of connecting to the server, I have remotely given privileges to my friend (user "bob").

So, you have the following error:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure java.net.ConnectException: Connection
refused
This could happen for a variety of reasons, and I'm quoting from this answer
If you get a SQLException: Connection refused or Connection timed out
or a MySQL specific CommunicationsException: Communications link
failure, then it means that the DB isn't reachable at all.
This can have one or more of the following causes:
IP address or hostname in JDBC URL is wrong.
Hostname in JDBC URL is not recognized by local DNS server.
Port number is missing or wrong in JDBC URL. [Assuming the one you mentioned is correct]
DB server is down.
DB server doesn't accept TCP/IP connections.
DB server has run out of connections.
Something in between Java and DB is blocking connections, e.g. a firewall or proxy.
To solve the one or the other, follow the following advice:
Verify and test them with ping.
Refresh DNS or use IP address in JDBC URL instead.
Verify it based on my.cnf of MySQL DB.
Start the DB.
Verify if mysqld is started without the --skip-networking option.
Restart the DB and fix your code accordingly that it closes connections in finally.
Disable firewall and/or configure
firewall/proxy to allow/forward the port.

Getting connection time out while running Oozie workflow through Java

I am getting following error when i try to run Oozie workflow using java
IO_ERROR : java.net.ConnectException: Connection timed out: connect
at org.apache.oozie.client.OozieClient.validateWSVersion(OozieClient.java:234)
at org.apache.oozie.client.OozieClient.createURL(OozieClient.java:300)
at org.apache.oozie.client.OozieClient.access$000(OozieClient.java:71)
at org.apache.oozie.client.OozieClient$ClientCallable.call(OozieClient.java:366)
at org.apache.oozie.client.OozieClient.run(OozieClient.java:547)
at oozieDemo.main(oozieDemo.java:27)
Caused by: java.net.ConnectException: Connection timed out: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
Here is my code:
OozieClient wc = new OozieClient("http:xxxxxxx/oozie");
System.out.println(" connection established....." + wc);
Properties conf = wc.createConfiguration();
conf.setProperty(OozieClient.APP_PATH,"hdfs:foo/xxx/workflow.xml");
conf.setProperty("jobTracker", "foo:8021");
conf.setProperty("nameNode","hdfs:xxxx");
conf.setProperty("queueName", "default");
conf.setProperty("appLibLoc","hdfs:/foo/xxx/lib");
String jobId = wc.run(conf);
System.out.println("Workflow job submitted");
So here I can see connection is getting established but unable to run the workflow.
I am new to this. So can't figure it out where exactly it is failing.

Connection timeout means either:
URL is incorrect or down, try pinging it.
Firewall is blocking it.
Default timeout expired.
Your internet access is down, which I'm going to assume isn't the case.

Create a jTDS connection string

my sql server instance name is MYPC\SQLEXPRESS and I'm trying to create a jTDS connection string to connect to the database 'Blog'. Can anyone please help me accomplish that?
I'm trying to do like this:
DriverManager.getConnection("jdbc:jtds:sqlserver://127.0.0.1:1433/Blog", "user", "password");
and I get this:
java.sql.SQLException: Network error IOException: Connection refused: connect
at net.sourceforge.jtds.jdbc.ConnectionJDBC2.<init>(ConnectionJDBC2.java:395)
at net.sourceforge.jtds.jdbc.ConnectionJDBC3.<init>(ConnectionJDBC3.java:50)
at net.sourceforge.jtds.jdbc.Driver.connect(Driver.java:184)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at SqlConnection.Connect(SqlConnection.java:19)
at main.main(main.java:11)
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(Unknown Source)
at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.sourceforge.jtds.jdbc.SharedSocket.createSocketForJDBC3(SharedSocket.java:305)
at net.sourceforge.jtds.jdbc.SharedSocket.<init>(SharedSocket.java:255)
at net.sourceforge.jtds.jdbc.ConnectionJDBC2.<init>(ConnectionJDBC2.java:323)
... 6 more

As detailed in the jTDS Frequenlty Asked Questions, the URL format for jTDS is:
jdbc:jtds:<server_type>://<server>[:<port>][/<database>][;<property>=<value>[;...]]
So, to connect to a database called "Blog" hosted by a MS SQL Server running on MYPC, you may end up with something like this:
jdbc:jtds:sqlserver://MYPC:1433/Blog;instance=SQLEXPRESS;user=sa;password=s3cr3t
Or, if you prefer to use getConnection(url, "sa", "s3cr3t"):
jdbc:jtds:sqlserver://MYPC:1433/Blog;instance=SQLEXPRESS
EDIT: Regarding your Connection refused error, double check that you're running SQL Server on port 1433, that the service is running and that you don't have a firewall blocking incoming connections.

Really, really, really check if the TCP/IP protocol is enabled in your local SQLEXPRESS instance.
Follow these steps to make sure:
Open "Sql Server Configuration Manager" in "Start Menu\Programs\Microsoft SQL Server 2012\Configuration Tools\"
Expand "SQL Server Network Configuration"
Go in "Protocols for SQLEXPRESS"
Enable TCP/IP
If you have any problem, check this blog post for details, as it contains screenshots and much more info.
Also check if the "SQL Server Browser" windows service is activated and running:
Go to Control Panel -> Administrative Tools -> Services
Open "SQL Server Browser" service and enable it (make it manual or automatic, depends on your needs)
Start it.
That's it.
After I installed a fresh local SQLExpress, all I had to do was to enable TCP/IP and start the SQL Server Browser service.
Below a code I use to test the SQLEXPRESS local connection. Of course, you should change the IP, DatabaseName and user/password as needed.:
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
public class JtdsSqlExpressInstanceConnect {
public static void main(String[] args) throws SQLException {
Connection conn = null;
ResultSet rs = null;
String url = "jdbc:jtds:sqlserver://127.0.0.1;instance=SQLEXPRESS;DatabaseName=master";
String driver = "net.sourceforge.jtds.jdbc.Driver";
String userName = "user";
String password = "password";
try {
Class.forName(driver);
conn = DriverManager.getConnection(url, userName, password);
System.out.println("Connected to the database!!! Getting table list...");
DatabaseMetaData dbm = conn.getMetaData();
rs = dbm.getTables(null, null, "%", new String[] { "TABLE" });
while (rs.next()) { System.out.println(rs.getString("TABLE_NAME")); }
} catch (Exception e) {
e.printStackTrace();
} finally {
conn.close();
rs.close();
}
}
}
And if you use Maven, add this to your pom.xml:
<dependency>
<groupId>net.sourceforge.jtds</groupId>
<artifactId>jtds</artifactId>
<version>1.2.4</version>
</dependency>

jdbc:jtds:sqlserver://x.x.x.x/database replacing x.x.x.x with the IP or hostname of your SQL Server machine.
jdbc:jtds:sqlserver://MYPC/Blog;instance=SQLEXPRESS
or
jdbc:jtds:sqlserver://MYPC:1433/Blog;instance=SQLEXPRESS
If you are wanting to set the username and password in the connection string too instead of against a connection object separately:
jdbc:jtds:sqlserver://MYPC/Blog;instance=SQLEXPRESS;user=foo;password=bar
(Updated my incorrect information and add reference to the instance syntax)

A shot in the dark, but
From the looks of your error message, it seems that either the sqlserver instance is not running on port 1433 or something is blocking the requests to that port

SQLServer runs the default instance over port 1433. If you specify the port as port 1433, SQLServer will only look for the default instance. The name of the default instance was created at setup and usually is SQLEXPRESSxxx_xx_ENU.
The instance name also matches the folder name created in Program Files -> Microsoft SQL Server. So if you look there and see one folder named SQLEXPRESSxxx_xx_ENU it is the default instance.
Folders named MSSQL12.myInstanceName (for SQLServer 2012) are named instances in SQL Server and are not accessed via port 1433.
So if your program is accessing a default instance in the database, specify port 1433, and you may not need to specify the instance name.
If your program is accessing a named instance (not the default instance) in the database DO NOT specify the port but you must specify the instance name.
I hope this clarifies some of the confusion emanating from the errors above.