com.maverick.ssh.SshException: EOF received from remote side [Unknown cause] - exception

When I tried to log in AIX server, through a java code/application, I am getting the below exception,
INFO: J2SSH:KEY_EXCHANGE_FAILURE
com.maverick.ssh.SshException: EOF received from remote side [Unknown cause]
at com.maverick.ssh2.TransportProtocol.b(Unknown Source)
at com.maverick.ssh2.TransportProtocol.j(Unknown Source)
at com.maverick.ssh2.TransportProtocol.nextMessage(Unknown Source)
at com.maverick.ssh.components.jce.DiffieHellmanGroup1Sha1.performClientExchange(Unknown Source)
at com.maverick.ssh2.TransportProtocol.e(Unknown Source)
at com.maverick.ssh2.TransportProtocol.processMessage(Unknown Source)
at com.maverick.ssh2.TransportProtocol.startTransportProtocol(Unknown Source)
at com.maverick.ssh2.Ssh2Client.connect(Unknown Source)
at com.maverick.ssh.SshConnector.connect(Unknown Source)
at com.maverick.ssh.SshConnector.connect(Unknown Source)
Server details :
Server type : AIX
Mode of connection : SSH
Authentication : password based authentication. Not key based.
I surfed in internet, but not able get clear answer for this issue. Please some one help me. Thanks in advance.

The java code in question is using the J2SSH Maverick API from SSHTOOLS Limited and is throwing the exception during key exchange. This specific error means the remote server disconnected whilst key exchange was being performed.
There are many potential reasons for this. It's likely that the server did not like something in the key exchange messages and disconnected or even seg-faulted. The resolution would be to ensure your using the latest version of the API above and if it continues to be a problem contact the company for support.

Related

Uploading tomcat application throws SSL Exception

I have implemented a web application in NetBeans using Tomcat 7. This application is working properly in localhost. I am trying to upload this application on a web hosting site and it seems to be uploaded properly. The problem is that at some point, it throws the following exception and i can't figure out what is the problem. I have read a few posts with the same problem but the problem still exists.
root cause
java.security.AccessControlException: access denied ("java.util.PropertyPermission" "ssl.TrustManagerFactory.algorithm" "read")
java.security.AccessControlContext.checkPermission(AccessControlContext.java:366)
java.security.AccessController.checkPermission(AccessController.java:555)
java.lang.SecurityManager.checkPermission(SecurityManager.java:549)
java.lang.SecurityManager.checkPropertyAccess(SecurityManager.java:1302)
java.lang.System.getProperty(System.java:706)
org.apache.http.conn.ssl.SSLSocketFactory.createSystemSSLContext(SSLSocketFactory.java:255)
org.apache.http.conn.ssl.SSLSocketFactory.createSystemSSLContext(SSLSocketFactory.java:366)
org.apache.http.conn.ssl.SSLSocketFactory.getSystemSocketFactory(SSLSocketFactory.java:204)
org.apache.http.impl.conn.SchemeRegistryFactory.createSystemDefault(SchemeRegistryFactory.java:82)
org.apache.http.impl.client.SystemDefaultHttpClient.createClientConnectionManager(SystemDefaultHttpClient.java:118)
org.apache.http.impl.client.AbstractHttpClient.getConnectionManager(AbstractHttpClient.java:466)
org.apache.http.impl.client.AbstractHttpClient.createHttpContext(AbstractHttpClient.java:286)
org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:851)
org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:805)
org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:784)
org.apache.jena.riot.web.HttpOp.execHttpGet(HttpOp.java:148)
org.apache.jena.riot.stream.LocatorURL.open(LocatorURL.java:47)
org.apache.jena.riot.stream.StreamManager.openNoMapOrNull(StreamManager.java:124)
org.apache.jena.riot.stream.StreamManager.open(StreamManager.java:81)
org.apache.jena.riot.RDFDataMgr.open(RDFDataMgr.java:725)
org.apache.jena.riot.RDFDataMgr.open(RDFDataMgr.java:714)
org.apache.jena.riot.RDFDataMgr.parse(RDFDataMgr.java:649)
org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:211)
org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:184)
org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:122)
org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:113)
org.apache.jena.riot.adapters.RDFReaderRIOT.read(RDFReaderRIOT.java:77)
com.hp.hpl.jena.rdf.model.impl.ModelCom.read(ModelCom.java:247)
com.hp.hpl.jena.util.FileManager.readModelWorker(FileManager.java:378)
com.hp.hpl.jena.util.FileManager.loadModelWorker(FileManager.java:309)
com.hp.hpl.jena.util.FileManager.loadModel(FileManager.java:261)
MyServlet.doPost(MyServlet.java:127)
javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
sun.reflect.GeneratedMethodAccessor30.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:601)
org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:274)
org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:271)
java.security.AccessController.doPrivileged(Native Method)
javax.security.auth.Subject.doAsPrivileged(Subject.java:536)
org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:306)
org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:166)
Just to mention that in the line of my class that is shown in the stack trace (MyServlet.doPost(MyServlet.java:127)) there is just a url to a page.
Any ideas would be appreciate!
The Tomcat server you are uploading to is running under a security manager which is not allowing Tomcat to read the ssl.TrustManagerFactory.algorithm system property. You need to request your hosting provider to adjust the security policy to allow Tomcat to read this property.

Pentaho Data Integration SQL connection

I am using Pentaho Data Integration and I am trying to connect to my database via MySQL but when I do I get this error.....
Error connecting to database [devdb2] : org.pentaho.di.core.exception.KettleDatabaseException:
Error occured while trying to connect to the database
Exception while loading class
org.gjt.mm.mysql.Driver
org.pentaho.di.core.exception.KettleDatabaseException:
Error occured while trying to connect to the database
Exception while loading class
org.gjt.mm.mysql.Driver
at org.pentaho.di.core.database.Database.normalConnect(Database.java:368)
at org.pentaho.di.core.database.Database.connect(Database.java:317)
at org.pentaho.di.core.database.Database.connect(Database.java:279)
at org.pentaho.di.core.database.Database.connect(Database.java:269)
at org.pentaho.di.core.database.DatabaseFactory.getConnectionTestReport(DatabaseFactory.java:86)
at org.pentaho.di.core.database.DatabaseMeta.testConnection(DatabaseMeta.java:2464)
at org.pentaho.ui.database.event.DataHandler.testDatabaseConnection(DataHandler.java:533)
at sun.reflect.GeneratedMethodAccessor55.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.pentaho.ui.xul.impl.AbstractXulDomContainer.invoke(AbstractXulDomContainer.java:329)
at org.pentaho.ui.xul.impl.AbstractXulComponent.invoke(AbstractXulComponent.java:139)
at org.pentaho.ui.xul.impl.AbstractXulComponent.invoke(AbstractXulComponent.java:123)
at org.pentaho.ui.xul.swt.tags.SwtButton.access$500(SwtButton.java:26)
at org.pentaho.ui.xul.swt.tags.SwtButton$4.widgetSelected(SwtButton.java:119)
at org.eclipse.swt.widgets.TypedListener.handleEvent(Unknown Source)
at org.eclipse.swt.widgets.EventTable.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Unknown Source)
at org.eclipse.swt.widgets.Display.readAndDispatch(Unknown Source)
at org.eclipse.jface.window.Window.runEventLoop(Window.java:820)
at org.eclipse.jface.window.Window.open(Window.java:796)
at org.pentaho.ui.xul.swt.tags.SwtDialog.show(SwtDialog.java:378)
at org.pentaho.ui.xul.swt.tags.SwtDialog.show(SwtDialog.java:304)
at org.pentaho.di.ui.core.database.dialog.XulDatabaseDialog.open(XulDatabaseDialog.java:115)
at org.pentaho.di.ui.core.database.dialog.DatabaseDialog.open(DatabaseDialog.java:62)
at org.pentaho.di.ui.spoon.delegates.SpoonDBDelegate.newConnection(SpoonDBDelegate.java:493)
at org.pentaho.di.ui.spoon.delegates.SpoonDBDelegate.newConnection(SpoonDBDelegate.java:478)
at org.pentaho.di.ui.spoon.Spoon.newConnection(Spoon.java:7770)
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 org.pentaho.ui.xul.impl.AbstractXulDomContainer.invoke(AbstractXulDomContainer.java:329)
at org.pentaho.ui.xul.impl.AbstractXulComponent.invoke(AbstractXulComponent.java:139)
at org.pentaho.ui.xul.impl.AbstractXulComponent.invoke(AbstractXulComponent.java:123)
at org.pentaho.ui.xul.swt.tags.SwtMenuitem.access$100(SwtMenuitem.java:27)
at org.pentaho.ui.xul.swt.tags.SwtMenuitem$1.widgetSelected(SwtMenuitem.java:77)
at org.eclipse.swt.widgets.TypedListener.handleEvent(Unknown Source)
at org.eclipse.swt.widgets.EventTable.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Unknown Source)
at org.eclipse.swt.widgets.Display.readAndDispatch(Unknown Source)
at org.pentaho.di.ui.spoon.Spoon.readAndDispatch(Spoon.java:1183)
at org.pentaho.di.ui.spoon.Spoon.start(Spoon.java:6966)
at org.pentaho.di.ui.spoon.Spoon.main(Spoon.java:567)
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 org.pentaho.commons.launcher.Launcher.main(Launcher.java:134)
Caused by: org.pentaho.di.core.exception.KettleDatabaseException:
Exception while loading class
org.gjt.mm.mysql.Driver
at org.pentaho.di.core.database.Database.connectUsingClass(Database.java:423)
at org.pentaho.di.core.database.Database.normalConnect(Database.java:352)
... 50 more
Caused by: java.lang.ClassNotFoundException: org.gjt.mm.mysql.Driver
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at org.pentaho.di.core.database.Database.connectUsingClass(Database.java:414)
... 51 more
If I used SQLite as my Connection Type it works but no data is returned when I goto explore it. So my question is how do I get MySQL working or get the data using SQLite?
Am I missing a library or a class?
I just came across the same issue while trying to query a MySQL Database from Pentaho.
Error connecting to database [Local MySQL DB] : org.pentaho.di.core.exception.KettleDatabaseException:
Error occured while trying to connect to the database
Exception while loading class
org.gjt.mm.mysql.Driver
Expanding post by #user979331 the solution is:
Download the MySQL Java Connector / Driver that is compatible with your kettle version
Unzip the zip file (in my case it was mysql-connector-java-5.1.31.zip)
copy the .jar file (mysql-connector-java-5.1.31-bin.jar) and paste it in your Lib folder:
PC: C:\Program Files\pentaho\design-tools\data-integration\lib
Mac: /Applications/data-integration/lib
Restart Pentaho (Data Integration) and re-test the MySQL Connection.
Additional interesting replies from others that could also help:
think to download the good JDBC driver version, compatible with your
PDI version:
https://help.pentaho.com/Documentation/8.1/Setup/JDBC_Drivers_Reference#MY_SQL
take the zip version ("platform independant") to extract the jar file
take into lib folder
see also proper way to handle it proposed by Ryan Tuck
Missing driver file.
This error is really common for people just getting started with PDI.
Drivers go in \pentaho\design-tools\data-integration\libext\JDBC for PDI. If you are using other tools in the Pentaho suite, you may need to copy drivers to additional locations for those tools. For reference, here are the appropriate folders for some of the other design tools:
Aggregation Designer: \pentaho\design-tools\aggregation-designer\drivers
Metadata Editor: \pentaho\design-tools\metadata-editor\libext\JDBC
Report Designer: \pentaho\design-tools\report-designer\lib\jdbc
Schema Workbench: \pentaho\design-tools\schema-workbench\drivers
If this transformation or job will run on another box, such as a test or production server, don't forget to include copying the jar file and restarting PDI or the Data Integration Server in your deployment considerations.
Turns out I will missing a class called mysql-connector-java-5.1.2.jar, I added it this folder (C:\Program Files\pentaho\design-tools\data-integration\lib) and it worked with a MySQL connection and my data and tables appear.
You need to download mysql-connector-java-5.1.46.tar.gz, not the latest version. The Driver class that Pentaho uses is not included in mysql-connector-java-8.xx.yy versions.
In addition to the other answers here, here's how you can do it on Ubuntu (14.04):
sudo apt-get install libmysql-java
this will download mysql-connector-java-5.x.x.jar to /usr/share/java/, which i believe also automatically creates a symlink named mysql-connector-java.jar.
Then, create a symlink in /your/path/to/data-integration/lib/:
ln -s /usr/share/java/mysql-connector-java.jar /your/path/to/data-integration/lib/mysql-connector-java.jar
At the present time, there is a simple way to fix this problem:
Go to Tools → MarketPlace and search for "PDI MySQL Plugin"
Install it ( this will automatically install the missing driver here: data-integration\plugins\databases\pdi-mysql-plugin\lib )
Restart Pentaho
Done.
To be concise and precise download the compatible jdbc (.jar) file compatible with your MySql version and put it in lib folder.
For example for MySQL 8.0.2 download Connector/J 8.0.20
Above answers were helpful, but for unknown reasons they did not seem to work.
So if you have already installed MySql workbench on your system, instead of downloading the jar files and struggling with the correct version just go to
C:\Program Files (x86)\MySQL\Connector J 8.0
and copy mysql-connector-java-8.0.12 (does not matter what version it is) the jar file in that location and paste it to C:\Program Files\pentaho\design-tools\data-integration\lib
First of all you need to download Mysql connector which is compatible with your pentaho version.after that paste it to data-integration/lib folder and restart your pentaho.
check this
https://help.pentaho.com/Documentation/8.1/Setup/JDBC_Drivers_Reference#MY_SQL

Glassfish Jdbc-connectioPool Issue

Hi I am getting the following exception frequently in glassfish can any one help me on this.
The log message is null.
The log message is null.
java.sql.SQLException: Error in allocating a connection. Cause: java.lang.IllegalStateException: Wrong XAState: 0
at com.sun.gjc.spi.base.DataSource.getConnection(DataSource.java:115)
at com.sify.beaserv.bean.PollBoxBean.getNode(PollBoxBean.java:754)
at com.sify.beaserv.bean.PollBoxBean.buildAlarm(PollBoxBean.java:317)
at com.sify.beaserv.bean.PollBoxBean.processNode(PollBoxBean.java:652)
at com.sify.beaserv.bean.PollBoxBean.onMessage(PollBoxBean.java:60)
at sun.reflect.GeneratedMethodAccessor185.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.sun.enterprise.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1011)
at com.sun.enterprise.security.SecurityUtil.invoke(SecurityUtil.java:175)
at com.sun.ejb.containers.BaseContainer.invokeTargetBeanMethod(BaseContainer.java:2929)
at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:4020)
at com.sun.ejb.containers.MessageBeanContainer.deliverMessage(MessageBeanContainer.java:1111)
at com.sun.ejb.containers.MessageBeanListenerImpl.deliverMessage(MessageBeanListenerImpl.java:74)
at com.sun.enterprise.connectors.inflow.MessageEndpointInvocationHandler.invoke(MessageEndpointInvocationHandler.java:179)
at $Proxy76.onMessage(Unknown Source)
at com.sun.messaging.jms.ra.OnMessageRunner.run(OnMessageRunner.java:258)
at com.sun.enterprise.connectors.work.OneWork.doWork(OneWork.java:76)
at com.sun.corba.ee.impl.orbutil.threadpool.ThreadPoolImpl$WorkerThread.run(ThreadPoolImpl.java:555)
The exception message Wrong XAState: 0 suggests that you're trying to use an XA driver, which is correct for two-phase commit. Is that true? Do you know which JDBC driver and which database vendor you're using? Do you get this message right at start up, or is it after you've been running successfully for a while?

c3p0 - hibernate - mysql

hibernate 3.6.8 final
c3p0 jar that came with hibernate 3.6.8 package -> c3p0-0.9.1.jar
1
15
40
0
5
2
The app seems to be working fine, however I get massive log calls with the following stacktrace:
org.apache.catalina.loader.WebappClassLoader loadClass
INFO: Illegal access: this web application instance has been stopped already. Could not load com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException. The eventual following stack trace is caused by an error thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access, and has no functional impact.
java.lang.IllegalStateException
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1566)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at com.mysql.jdbc.Util.getInstance(Util.java:386)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1013)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:987)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:982)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:927)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2411)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2153)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:792)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.GeneratedConstructorAccessor38.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
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 com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:134)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:171)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:152)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1074)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1061)
at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1796)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:620)
Any information on how to remove that INFO log would be very much helpful thanks!
UPDATE: Is this a critical error? Or can should I just ignore it?
After a search on the web regarding this issue, I found some similar issues reported by several people. All of them point to a common problem: Threads. Basically, if you start new threads in your application (either in your code or by using a third party tool like Quartz, you have to make sure that all of the threads are stopped appropriately when the application is undeployed from the server. Here are some quotes from the searches:
Mikolaj Rydzewski wrote:
It looks like after webapp's instance has been undeployed, background quartz thread wants to do something and then exception occurs.
Another (and better explanation) on jspwiki.org:
It is possible that this is caused by Tomcat unsuccessfully reloading the web application. The app is unloaded, but all threads don't get shut down properly. As a result, when the threads try to run, they get clobbered by the fact that Tomcat has shut down its classloader, and an error is logged.
So, in order to solve this issue you have to make sure all threads started by your application will be stopped at application undeployment (or redeployment, it's the same). You can do this by registering a ServletContextListener to your application server and stopping your threads inside contextDestroyed(ServletContextEvent) method.
If you are using log4j, change your logging settings to something like this (the word ERROR replace INFO) :
log4j.rootLogger=ERROR, file, stdout
log4j.logger.org.hibernate=ERROR
They are located in the the log4j.properties file in yr project.
OK I switched to boneCP, c3p0 does not really seem to work for java6!!!

Installing hudson slave on windows xp

I am trying to install a slave on windows xp on a different machine from the master. I tried clicking on new node and it only give me the option of choosing dumb slave. Is it supposed to be like that? Anyway, I fill out the node name as "Test" and i select launch using jnlp and i hit save. Now when I click on that node i download the slave-agent.jnlp and slave.jar files from that screen and i open a command prompt and enter java -jar slave.jar -jnlpUrl http://servername:portnumber/hudson/computer/Test/slave-agent.jnlp but I get the following java errors:
java.net.ConnectException: Connection timed out: 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 hudson.remoting.Engine.connect(Engine.java:265)
at hudson.remoting.Engine.run(Engine.java:185)
When i try to run it from the web interface it cannot connect and it looks like it is trying to use a port number like 59870 instead of the real portnumber to connect to the host. Does anyone know why I can't install the slave agent?
found it. You need to open that port number on the machine the master slave is on.