Develop Reference

Server closes connection when trying to connect Java application to Redshift database

I'm trying to connect a Java application to a Redshift database. When I run DriverManager.getConnection(), it sits for a long time (minutes) and finally throws an exception:
Exception in thread "main" java.sql.SQLException:
[Amazon](600001) The server closed the connection.
at com.amazon.support.channels.TLSSocketChannel.readBytes(Unknown Source)
at com.amazon.support.channels.TLSSocketChannel.doHandshake(Unknown Source)
at com.amazon.support.channels.TLSSocketChannel.<init>(Unknown Source)
at com.amazon.redshift.client.PGClient.checkSSL(Unknown Source)
at com.amazon.redshift.client.PGClient.<init>(Unknown Source)
at com.amazon.redshift.core.PGJDBCConnection.connect(Unknown Source)
at com.amazon.jdbc.common.BaseConnectionFactory.doConnect(Unknown Source)
at com.amazon.jdbc.common.AbstractDriver.connect(Unknown Source)
at com.amazon.redshift.jdbc.Driver.connect(Unknown Source)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:247)
I can connect using the same connection string and credentials from SQL Workbench on the same machine. Also, if I supply bad credentials to the connection, it gives an authentication error. So I don't believe this is an Amazon security issue, which seems to be the most common reason for an inability to connect.
Other ideas?
Update: The mystery deepens. Other members of the team are able to check out the code and run it successfully. We have the driver in our team's shared maven repository.

Well... not sure what the problem was. But I did an Eclipse update and it went away.

Axis2 SocketTimeoutException: Read Time Out

I am trying the build a SOAP client to access the National Weather Service NDFD SOAP Service. I'm using Axis2 1.6.2 with code generated with wsdl2java.
Every time I try to retrieve data, I receive a AxisFault saying Read timed out.
I have tried to increase the timeout time to up to 500 s, but all that does is make it wait longer before giving the same error.
Exception in thread "main" org.apache.axis2.AxisFault: [was class java.net.SocketTimeoutException] Read timed out
at org.apache.axis2.AxisFault.makeFault(AxisFault.java:430)
at gov.weather.graphical.xml.dwmlgen.wsdl.ndfdxml_wsdl.NdfdXMLStub.fromOM(NdfdXMLStub.java:26499)
at gov.weather.graphical.xml.dwmlgen.wsdl.ndfdxml_wsdl.NdfdXMLStub.nDFDgen(NdfdXMLStub.java:595)
at he.andrew.ndfd.NDFDData.getData(NDFDData.java:47)
at he.andrew.ndfd.NDFDData.main(NDFDData.java:25)
Caused by: java.lang.RuntimeException: [was class java.net.SocketTimeoutException] Read timed out
at com.ctc.wstx.util.ExceptionUtil.throwRuntimeException(ExceptionUtil.java:18)
at com.ctc.wstx.sr.StreamScanner.throwLazyError(StreamScanner.java:731)
at com.ctc.wstx.sr.BasicStreamReader.safeFinishToken(BasicStreamReader.java:3657)
at com.ctc.wstx.sr.BasicStreamReader.getText(BasicStreamReader.java:809)
at com.ctc.wstx.sr.BasicStreamReader.getElementText(BasicStreamReader.java:679)
at org.apache.axiom.util.stax.wrapper.XMLStreamReaderWrapper.getElementText(XMLStreamReaderWrapper.java:100)
at org.apache.axiom.util.stax.wrapper.XMLStreamReaderWrapper.getElementText(XMLStreamReaderWrapper.java:100)
at org.apache.axiom.om.impl.llom.SwitchingWrapper.getElementText(SwitchingWrapper.java:936)
at javax.xml.stream.util.StreamReaderDelegate.getElementText(Unknown Source)
at org.apache.axiom.util.stax.wrapper.XMLStreamReaderWrapper.getElementText(XMLStreamReaderWrapper.java:100)
at org.apache.axiom.util.stax.debug.XMLStreamReaderValidator.getElementText(XMLStreamReaderValidator.java:75)
at gov.weather.graphical.xml.dwmlgen.wsdl.ndfdxml_wsdl.NdfdXMLStub$NDFDgenResponse$Factory.parse(NdfdXMLStub.java:5612)
at gov.weather.graphical.xml.dwmlgen.wsdl.ndfdxml_wsdl.NdfdXMLStub.fromOM(NdfdXMLStub.java:26353)
... 3 more
Caused by: java.net.SocketTimeoutException: Read timed out
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.io.BufferedInputStream.read1(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)
at org.apache.commons.httpclient.WireLogInputStream.read(WireLogInputStream.java:69)
at org.apache.commons.httpclient.ChunkedInputStream.read(ChunkedInputStream.java:182)
at java.io.FilterInputStream.read(Unknown Source)
at org.apache.commons.httpclient.AutoCloseInputStream.read(AutoCloseInputStream.java:108)
at java.io.FilterInputStream.read(Unknown Source)
... more not included
The error seems to be the same as the one here: Exception in thread "main" org.apache.axis2.AxisFault: Read timed out. However, I don't quite understand any of the responses to that question.
One final note. In order to avoid a "411 Error: Length Required", I had to turn off the Chunked option. I'm not sure if this is relevant.
Does anyone know what might be the problem?

I ran into this error on a project, and the root cause was a proxy server setting. I had to modify the proxy to allow the communication to the service I was trying to hit. My code was running as part of a custom application that used its own proxy. So this may also be something to try.

Increasing client packet size for a Java connection to a mySQL DB

I'm trying to connect to an external mySQL DB through a Java program. When I attempt to connect, I obtain the following exception:
Exception in thread "main" com.mysql.jdbc.PacketTooBigException: Packet for query is too large (4739923 > 1048576). You can change this value on the server by setting the max_allowed_packet' variable.
at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:605)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1078)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2397)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2430)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2215)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:813)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
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.ConnectionImpl.getInstance(ConnectionImpl.java:399)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:334)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at Main.main(Main.java:48)
This is only for this external server. I was able to connect to a local server I set up without this issue at all.
I did some research on this and it talked about increasing my client max_allowed_packet size through a /etc/my.cnf file. I attempted to do this without any success. Would somebody be able to walk me through this as I can't even find the .cnf file. Is this even the right approach for a Java based connection?
Thanks in advance.

On the server, you must change your mysql configuration file. You will need to find it based on your operation system. See https://dev.mysql.com/doc/refman/5.6/en/option-files.html
You should not need to do anything on the client side to set this. Just send a large amount of data.

server in Java, client in C - cannot get the data

I am writing code for tcp-ip server client... the problem I am facing is :: My server is in Java and listening to a port, if anything it found simply it prints what it found.
I have a client in Java and a client in C . When I use my Java client and send String "hello server" - the server finds that and prints that BUT when the C client sends it using the "send" of winsock.h, the Java server gives error on the line :: (I have used Buffereader and readline to get the data from tcp-ip port in Java server)
commandFromPortal = inFromClient.readLine();
and the errors are ::
Connection reset
at java.net.SocketInputStream.read(Unknown Source)
at sun.nio.cs.StreamDecoder.readBytes(Unknown Source)
at sun.nio.cs.StreamDecoder.implRead(Unknown Source)
at sun.nio.cs.StreamDecoder.read(Unknown Source)
at java.io.InputStreamReader.read(Unknown Source)
at java.io.BufferedReader.fill(Unknown Source)
at java.io.BufferedReader.readLine(Unknown Source)
at java.io.BufferedReader.readLine(Unknown Source)
at org.snmp4j.NOCAlarmManager.Clientnew.run
What should I do ??? Any suggestion ??

It sounds like the socket is buffering when you write to it and the queued data is not being flushed (sent) before you close the socket (you are closing it properly, right?). The fact that it works when you add a newline (\n) seems to confirm this. So you have to flush the buffer on the socket before you close it. I don't work with winsocks, but from this website I gather you should call shutdown(sock,SD_SEND) (if that doesn't work, check the winsock documentation for how to flush the socket buffer).

You need to use a Middleware to introduce transparency.
Middleware frameworks are designed to mask heterogeneity of networks and hardware. Most middleware frameworks also mask heterogeneity of operating systems or programming languages, or both.
A few such as CORBA could be used.

HTTPClient-java.net.SocketException: Unconnected sockets not implemented thrown

Iam using HTTPClient 4.0 to connect a remote server and transfer file using HTTPS.
When i tried to connect i get the exception "java.net.SocketException: Unconnected sockets not implemented".
Please look at the stack trace
java.net.SocketException: Unconnected sockets not implemented
at java.lang.Throwable.<init>(Throwable.java:196)
at java.lang.Exception.<init>(Exception.java:41)
at java.io.IOException.<init>(IOException.java:40)
at java.net.SocketException.<init>(SocketException.java:29)
at javax.net.SocketFactory.createSocket(SocketFactory.java:2)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.apache.commons.httpclient.protocol.ReflectionSocketFactory.createSocket(Unknown Source)
at org.apache.commons.httpclient.protocol.SSLProtocolSocketFactory.createSocket(Unknown Source)
at org.apache.commons.httpclient.HttpConnection.open(Unknown Source)
at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(Unknown Source)
at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(Unknown Source)
at org.apache.commons.httpclient.HttpClient.executeMethod(Unknown Source)
at org.apache.commons.httpclient.HttpClient.executeMethod(Unknown Source)
at co.com.personalsoft.ftpseguro.utilidades.TransmisionHTTP.ejecutarTransmisionHTTP(TransmisionHTTP.java:107)
at co.com.personalsoft.ftpseguro.utilidades.TransmisionFTPNew.ejecutarTransmisionAuto(TransmisionFTPNew.java:483)
at co.com.personalsoft.ftpseguro.utilidades.TransmisionFTPNew.ejecutarTransmision(TransmisionFTPNew.java:1016)
at co.com.personalsoft.ftpautomatico.ConexionThread.run(ConexionThread.java:58)
at java.lang.Thread.run(Thread.java:595)
The same error is found while using HTTP Client 3.1.
My Environment
Application Server : Websphere application server 6.1.0.23
Java : JDK 1.5.0.16

Actually a more complete answer than suppressingfire is
Add com.ibm.ws.admin.client_7.0.0.jar to java build
This solves the java.lang.NoClassDefFoundError: com.ibm.ffdc.Manager error.
Add to setup:
import java.security.Security;
...
Security.setProperty("ssl.SocketFactory.provider", "com.ibm.jsse2.SSLSocketFactoryImpl");
This solves the Cannot find the specified class com.ibm.websphere.ssl.protocol.SSLSocketFactory

When I enabled javax.net.debug, I noticed that there was a missing class com.ibm.websphere.com.ibm.websphere.ssl.protocol.SSLSocketFactory.
I was experiencing trouble in unit tests that invoke httpclient. What I ended up doing was to add this line to my TestClass.setUp()
Security.setProperty("ssl.SocketFactory.provider", "com.ibm.jsse2.SSLSocketFactoryImpl");