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connection to Cloudera Impala / Hive outside the cluster

i am working with cloudera impala server version 5.4.7
first to make sure the port is open i have validate it with telnet.
Class.forName("org.apache.hive.jdbc.HiveDriver");
DriverManager.setLoginTimeout(30);
try (java.sql.Connection connection = DriverManager.getConnection("jdbc:hive2://12.23.56.789:123456/someName;auth=noSasl"))
{ System.out.println("connected"); }
But i never succeed to connect
all i get is this error from timeout:
what could be the problem ?
i am using the exact same hive version as the cloudera version
[14 Apr 2016 06:27:26,797] [ERROR] [main] [org.apache.hive.jdbc.HiveConnection] - Error opening session
org.apache.thrift.transport.TTransportException: java.net.SocketTimeoutException: Read timed out
at org.apache.thrift.transport.TIOStreamTransport.read(TIOStreamTransport.java:129)
at org.apache.thrift.transport.TTransport.readAll(TTransport.java:86)
at org.apache.thrift.protocol.TBinaryProtocol.readAll(TBinaryProtocol.java:429)
at org.apache.thrift.protocol.TBinaryProtocol.readI32(TBinaryProtocol.java:318)
at org.apache.thrift.protocol.TBinaryProtocol.readMessageBegin(TBinaryProtocol.java:219)
at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:69)
at org.apache.hive.service.cli.thrift.TCLIService$Client.recv_OpenSession(TCLIService.java:156)
at org.apache.hive.service.cli.thrift.TCLIService$Client.OpenSession(TCLIService.java:143)
at org.apache.hive.jdbc.HiveConnection.openSession(HiveConnection.java:475)
at org.apache.hive.jdbc.HiveConnection.<init>(HiveConnection.java:181)
at org.apache.hive.jdbc.HiveDriver.connect(HiveDriver.java:105)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at com.datorama.core.service.delivery.providers.DatabaseProvider.main(DatabaseProvider.java:330)
Caused by: java.net.SocketTimeoutException: Read timed out
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.io.BufferedInputStream.fill(Unknown Source)
at java.io.BufferedInputStream.read1(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)
at org.apache.thrift.transport.TIOStreamTransport.read(TIOStreamTransport.java:127)
... 13 more
Exception in thread "main" java.sql.SQLException: Could not establish connection to jdbc:hive2://54.69.2.250:21050/sage_global;auth=noSasl: java.net.SocketTimeoutException: Read timed out
at org.apache.hive.jdbc.HiveConnection.openSession(HiveConnection.java:486)
at org.apache.hive.jdbc.HiveConnection.<init>(HiveConnection.java:181)
at org.apache.hive.jdbc.HiveDriver.connect(HiveDriver.java:105)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at com.datorama.core.service.delivery.providers.DatabaseProvider.main(DatabaseProvider.java:330)
Caused by: org.apache.thrift.transport.TTransportException: java.net.SocketTimeoutException: Read timed out
at org.apache.thrift.transport.TIOStreamTransport.read(TIOStreamTransport.java:129)
at org.apache.thrift.transport.TTransport.readAll(TTransport.java:86)
at org.apache.thrift.protocol.TBinaryProtocol.readAll(TBinaryProtocol.java:429)
at org.apache.thrift.protocol.TBinaryProtocol.readI32(TBinaryProtocol.java:318)
at org.apache.thrift.protocol.TBinaryProtocol.readMessageBegin(TBinaryProtocol.java:219)
at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:69)
at org.apache.hive.service.cli.thrift.TCLIService$Client.recv_OpenSession(TCLIService.java:156)
at org.apache.hive.service.cli.thrift.TCLIService$Client.OpenSession(TCLIService.java:143)
at org.apache.hive.jdbc.HiveConnection.openSession(HiveConnection.java:475)
... 5 more
Caused by: java.net.SocketTimeoutException: Read timed out
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.io.BufferedInputStream.fill(Unknown Source)
at java.io.BufferedInputStream.read1(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)
at org.apache.thrift.transport.TIOStreamTransport.read(TIOStreamTransport.java:127)
... 13 more

We do a good deal of querying from outside the cluster using JDBC. While I believe it may be possible to use the Hive JDBC driver, you'll certainly need to set a proper port in your JDBC connections string, likely 21050 for Impala. You'll need to ensure that your host name (or IP address) points to an instance running the Impala daemon (for Hive you might point to a namenode). My guess is that the port number is wrong, as it seems that the error is simply failure to establish a top connection.
We decided to use the specific driver supplied by Cloudera for Impala, although that may not be necessary. We also set up a load balancer so there is one stable address to direct queries to, rather than requiring the caller to pick a specific Impala instance. This also spreads the load evenly and let's us make changes in the cluster without external callers needing to change anything.

Failed to connect to MySQL database

I get this console error every time I try to run this rs private server. Pretty much everything is connected to a mysql db.
I've been messing around with this for quite awhile but can't figure out whats wrong. If there is any specific files you may need to look at to help me figure out whats wrong, tell me and I'll post it.
All help would be highly appreciated!
[Stage - 1] Launching Elunity...
[Stage - 2] Loaded object configurations
[Stage - 3] Loaded region configurations
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet successfully received from the server was 1 432 637 479 787 milliseconds ago. The last packet sent successfully to the server was 0 milliseconds ago.
Failed to connect to MySQL database
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2214)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:773)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:352)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at paladious.model.players.Highscores.process(Highscores.java:17)
at paladious.Server.main(Server.java:117)
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet successfully received from the server was 1 432 637 479 777 milliseconds ago. The last packet sent successfully to the server was 0 milliseconds ago.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:341)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2137)
... 13 more
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:253)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:290)
... 14 more
[Stage - 4] Loaded single event manager
[Stage - 7] Loaded NPC drops
[Stage - 8] Loaded player punishments and starters
[Stage - 10] Elunity online on port :43594
Thanks in advance! :)

This is a wrapped exception and not really interesting. It is the root cause of the exception which actually tells us something about the root cause. Please look a bit further in the stacktrace. The chance is big that you'll then face a SQLException: Connection refused or SQLException: Connection timed out.
If this is true in your case as well, then all the possible causes are:
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.
DB server is down.
DB server doesn't accept TCP/IP connections.
Something in between Java and DB is blocking connections, e.g. a firewall or proxy.
To solve the one or the either, follow the following advices:
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 it.
Verify if mysqld is started without the --skip-networking option.
Disable firewall and/or configure firewall/proxy to allow/forward
the port.

What is reason for mysql database couldn't insert huge data set continuously?

I'm trying to read given web link, web pages paragraph by paragraph and insert that data into database.
Every time after reading and inserting about 20 web pages that gives following error messages.
I'm working in Xampp mysql server. After clearing history,cookies then work again properly. Then after reading web pages and inserting same errors occurs.
Isn't there any proper solution? Some stack overflow question mentioning about some idea to edit some config file.
Because of working me in windows environment I'm not clear about what they are mentioning.They mention increase maximum connection. But not clear about how I can edit some file (Not clear about where store that config file in windows environment) they mentioning.
Error message:
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.GeneratedConstructorAccessor8.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:343)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2137)
... 12 more
Caused by: java.net.SocketException: No buffer space available (maximum connections reached?): connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:253)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:292)
... 13 more
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.GeneratedConstructorAccessor8.newInstance(Unknown Source)

in Mysql my.ini or it may be my-default.ini file set max_allowed_packet=32M
after that restart mysql service.
you can specify size as per your need.
or
with mysql command shell
shell > mysql --max_allowed_packet=32M

RMI connection refused on localhost

I am trying to learn RMI coding and when I run server side of RMI I get connection refused.
This is my server main method
public static void main(String[] args)throws Exception {
Implementation impl=new Implementation();
Naming.rebind("//localhost:2020/RMI", impl);
System.out.println("Implementation has been bind to the name RMI and is ready for use");
}
I believe that the code for Implementation does not matter as it simply is the implemented interface that will run the code. The exception I am getting is this
Exception in thread "main" java.rmi.ConnectException: Connection refused to host: localhost; nested exception is:
java.net.ConnectException: Connection refused: connect
at sun.rmi.transport.tcp.TCPEndpoint.newSocket(Unknown Source)
at sun.rmi.transport.tcp.TCPChannel.createConnection(Unknown Source)
at sun.rmi.transport.tcp.TCPChannel.newConnection(Unknown Source)
at sun.rmi.server.UnicastRef.newCall(Unknown Source)
at sun.rmi.registry.RegistryImpl_Stub.rebind(Unknown Source)
at java.rmi.Naming.rebind(Unknown Source)
at epl362Project.Server.main(Server.java:10)
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(Unknown Source)
at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(Unknown Source)
... 7 more
What am I doing wrong? both client and server sides will run on my laptop as this is just an exercise. Am I missing something or is there something wrong with my code? Please besides giving me the answer explain why it is so since I do not just want to make it work, I am trying to learn.
**EDIT
I found out why my code was not working. I was missing a line of code that said
LocateRegistry.createRegistry(2020);
which I found from other questions here on stackoverflow. But there was no explanation nor did I find one online as to why this code was needed for RMI to work properly. Does anyone have an explanation?

The target of Naming.rebind() is the RMI Registry. It has to be running. It wasn't running. So you couldn't connect to it. So you got a ConnectException.
I believe that the code for Implementation does not matter as it simply is the implemented interface that will run the code.
This is both meaningless and irrelevant. Interfaces do not 'run the code'. Methods in classes run the code, and in this case the implementation class runs the code. However your problem is not in 'run[ning] the code', it is in connecting to the Registry.

Java and MySql connection problem

I am using Java+MySql. I am trying to add bulk data (around 40 million records). My application works fine for couple of hundred thousands records but after that it starts giving me following exception:
Exception in thread "main" com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1116)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:344)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2333)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2370)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2154)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:792)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.GeneratedConstructorAccessor5.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:381)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at net.jboss.Database.DatabaseConnection.getConnection(DatabaseConnection.java:48)
at net.jboss.emp.idm.adta(mde.java:96)
at net.jboss.emp.idm.main(mde.java:69)
Caused by: java.net.SocketException: No buffer space available (maximum connections reached?): 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 java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:257)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:294)
... 16 more
I googled this problem and tried almost every option (updating windows registry, changing my.cnf file, changing mysql global parameters etc.) but its not working.

I was hitting a similar problem a couple of hours ago. With the default settings, I could write some 15K records in a single transaction. Attempting to write any more than that gave me the exact same message ("No buffer space available (maximum connections reached?): connect") .
I then broke down the transactions in chunks of 1000 records (my application requirements allowed for it) and I still received the message after the 15th iteration. My application was diligently creating a new EntityManager and closing it for each iteration.
The solution was to clear the cache for that particular type of entity in between iterations (you can also clear the cache by entity) .
EntityManagerFactory.getCache().evictAll or evict(...)

It seems connection isn't being closed properly. I would recommend you to use connection-pooling
Also See
Connection pooling with MySQL Connector/J

this could be probably either lost connection with mysql or
your code could not be able to close existing connetction as u said it work for starting some records. so incresce max connection with mysql or try to check with other program when u get this error message if mysql accept connection from other program.

I was having the exact same problem and I fixed it by connectionname.close(); statement after every time an executable statement is called.

this can resolve your issue now :)
CommunicationsException