The Connection Server

This is a simple symptom-cause-solution blog entry only. I hope these blogs will help fellow administrators. Symptom With an Active Directory Authenticator configured, if a user logs in once with incorrect credentials further attempts to log in will fail, even with the correct username and password (until the server is restarted). If the user continues to login with correct credentials, WebLogic will eventually lockout the account. Cause This is a known bug for WebLogic 10 MP1. During authentication the AD provider binds twice using the same LDAP connection, once with the username password being authenticated, and once with the credentials supplied when you configure the LDAP provider. If authentication fails, the second binding doesn’t happen, and the unauthenticated LDAP connection is returned to the internal LDAP connection pool. This poses a problem when later trying to authenticate and the unauthenticated LDAP connection is retrieved from the pool... -Cobb...

This is a simple symptom-cause-solution blog entry only. I hope these blogs will help fellow administrators. Symptom The WebLogic admin or managed server is running, but telnetting to it fails, with an error like: Trying 10.123.123.123... telnet: connect to address 10.123.123.123: Connection refused Cause You may be using a development/limited license. These restrict WebLogic to accept connections from up to 5 different IP addresses and then stop accepting connections from any other IP. If you have multiple interfaces on the server, WebLogic may be listening on one of the others. If you do not specify a listen address for a admin or managed server, it will listen on all interfaces. Solution Replace the dev license with a purchased one, or restart the server to clear the 5 IPs that it accepts connection from. Change the listen address, or telnet to the correct address.

This is a simple symptom-cause-solution blog entry only. I hope these blogs will help fellow administrators. Symptom On Red Hat Enterprise Linux 4 (and possibly other flavours and versions) all weblogic processes are disappearing and there are no errors in the server logs. Upon closer inspection the processes are being killed by the OS. The Linux "dmesg" command shows log messages like: Out of Memory: Killed process 22043 Cause The processes are using up too much low- (under 640k) or high-memory and the Linux OOM-Killer is killing the processes. Solution Either disable OOM-killer, or make it work more aggresively. To disable, run this command: echo "0" > /proc/sys/vm/oom-kill To make more aggressive: echo "250" > /proc/sys/vm/lower_zone_protection References http://en.wikipedia.org/wiki/Out_of_memory http://www.linux-archive.org/red-hat-linux/39907-out-memory-issue.html

The Connection Server is the name of this site. That's right, there is no technology officially called a 'connection server'. However it could describe any number of technologies that we use everyday in the corporate sys admin world. Any type of server must accept connections from clients in order to respond, so whether its a HTTP server, JEE server or sql/database server, its pretty much a connection server too. The articles at this site will touch on all these types of technologies. In case you were wondering... HTTP Servers , which handle HTTP connections, accept and process requestsand return HTML code which is processed by an internet browser (Eg. Internet Explorer, Firefox, Chrome, Safari and Opera). The internet browser renders the HTML code as formatted text and graphics. Common HTTP servers include Apache and IIS. Application Servers , such as WebLogic, WebSphere, JBoss and Tomcat, usually include a basic HTTP server, but are also able to run JEE (Java Enterprise...

This is a simple symptom-cause-solution blog entry only. I hope these blogs will help fellow administrators. Symptom Getting the following exception (regularly) in the Admin server logs. HTTPClntLogin: Login rejected with code: 'Failed', reason: java.net.ProtocolException: HTTP tunneling is disabled at weblogic.rjvm.http.HTTPServerJVMConnection.acceptJVMConnection(HTTPServerJVMConnection.java:88) at weblogic.rjvm.http.TunnelLoginServlet.service(TunnelLoginServlet.java:80) at javax.servlet.http.HttpServlet.service(HttpServlet.java:820) at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:226) at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:124) at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:283) at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:175) at weblogic.servlet.internal.WebAppServletContext$ServletInvocation...

The Connection Server is an informal blog about a range of professional server-related topics, with a focus on the everyday tasks of a corporate IT infrastructure administrator. Articles range from hard-core technical tips to more business-oriented discussions. What technologies do I cover? Potentially anything used in the corporate IT world, but to name a few big ones: Java (J2EE, J2SE and J2ME) Oracle WebLogic (previously BEA WebLogic) WebSphere and JBoss Oracle DB Apache and IIS Windows, AIX, Solaris and Red Hat Although a few articles are aimed at helping beginners become more advanced administrators or developers, most articles assume at least a medium level of technical knowledge.

This is a simple symptom-cause-solution blog entry only. I hope these blogs will help fellow administrators. Symptom There is no license.bea, UpdateLicense.cmd or UpdateLicense.sh files in the BEA_HOME directory of WebLogic 10.3. Cause When Oracle bought BEA they decided to do away with this approach to licensing. Solution When you download WebLogic 10.3, you are getting the full version. That is, you do not need to do anything to fully enable the product. Although technically you do not need to do anything to use this product, legally you will need to purchase a license from Oracle. Contact an Oracle sales person for this. Previous versions of WebLogic, including 10.0, have not been changed, so you still require the license.bea file for these.

This is a simple symptom-cause-solution blog entry only. I hope these blogs will help fellow administrators. Symptom On Unix-based systems, log message like: Failed to listen on port 8081, failure count: 1, failing for 0 seconds, java.net.SocketException: Too many open files Cause The value of the "Maximum Open Socket" WebLogic setting is set higher than the the Unix limit (obtained by running the "ulimit -a" command). Solution Either decrease the value of "Maximum Open Socket" (located on the managed server's Tuning tab) to be less than the Unix limit, or increase the Unix limit. Investigate why there are so many requests being made. References Although this particular issue doesn't seem to be documented, you can see many other SocketException scenarios at http://www.insideexceptions.com/en/jdk-1-5-0/java-net-SocketException.html . It's a very helpful resource.

This is a simple symptom-cause-solution blog entry only. I hope these blogs will help fellow administrators. Symptom In WebLogic 9.2, adding an account to the Operator group has no effect if the account is also added to another group. Cause This is a known bug in WebLogic 9.2. Solution A patch is provided with the 9.2 installation. Ensure %BEA_HOME%\patch_weblogic920\patch_jars\CR285163_920GA.jar; is on the classpath. References None.

This is a simple symptom-cause-solution blog entry only. I hope these blogs will help fellow administrators. Symptom After removing a windows service, when trying to recreate it, the following error may be displayed: DeleteService failed - The specified service has been marked for deletion. (0x430) Cause The service is still in-use (at least to some degree). Solution Close any Microsoft Management Console (MMC) sessions, kill any processes, etc. Note the service can be accessed remotely, so also consider that remote users may be viewing the service. References None.

This is a simple symptom-cause-solution blog entry only. I hope these blogs will help fellow administrators. Symptom java.lang.NullPointerException at weblogic.utils.FileUtils.remove(FileUtils.java:203) at weblogic.management.mbeans.custom.Component.removeTempModule(Component.java:353) at weblogic.management.mbeans.custom.Component.initializeTwoPhase(Component.java:435) at weblogic.management.mbeans.custom.Component.initialize(Component.java:282) at weblogic.management.mbeans.custom.EJBComponent.findOrCreateEJBDescriptor(EJBComponent.java:220) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:324) at weblogic.management.internal.DynamicMBeanImpl.invokeLocally(DynamicMBeanImpl.java:755) at weblogic.management.internal.DynamicMBe...

This is a simple symptom-cause-solution blog entry only. I hope these blogs will help fellow administrators. Symptom javax.naming.NoPermissionException: User does not have permission on weblogic.management.home to perform lookup operation. at weblogic.jndi.internal.ServerNamingNode.checkPermission(ServerNamingNode.java:365) at weblogic.jndi.internal.ServerNamingNode.checkLookup(ServerNamingNode.java:329) at weblogic.jndi.internal.ServerNamingNode.lookupHere(ServerNamingNode.java:153) at weblogic.jndi.internal.BasicNamingNode.lookup(BasicNamingNode.java:188) at weblogic.jndi.internal.BasicNamingNode.lookup(BasicNamingNode.java:196) at weblogic.jndi.internal.BasicNamingNode.lookup(BasicNamingNode.java:196) at weblogic.jndi.internal.WLEventContextImpl.lookup(WLEventContextImpl.java:258) at weblogic.jndi.internal.WLContextImpl.lookup(WLContextImpl.java:363) at javax.naming.InitialContext.lookup(InitialContext.java:361) Cause In releases prior to WebLogic ...

Looking at learning more about WebLogic? In this article I will give my opinions on the books I have encountered throughout my career. If you're considering buying any of these books, then use the amazon links to support this site (and probably get the best available price). BEA WebLogic Server 8.1: Unleashed About four years ago I decided on a career change, and made the switch from Java developer to WebLogic Admin. On my first day on the job I was told that this book would be my bible, and to this day I still think it is the best WebLogic book available for learning WebLogic 8.1. In fact it is the only book I truly recommend, unless you wanting something updated for WebLogic 9 and later. WebLogic: The Definitive Guide I know this book gets reasonable reviews, but for a beginner or even every-day-admin I really wouldn't bother. There are definitely topics that are well covered and if its the topic you're after, you're in luck... The problem with t...

For J2EE developers who are not familiar with WebLogic, you can write debug and error messages to the server logs very easily. When to Write to WebLogic Server Logs Any debug, warning or error messages relating to the server or infrastructure. For example, information or errors with the following: Connecting to other components/systems. Database access, setup, etc. LDAP HTTP request/response Deployment dependencies Do not write to the server logs if you are handling the following: Unexpected user input Application debug/info/warning messages. (Write these to your own application logs.) How to do it Writing to the WebLogic server logs is simple. Just use LoggingHelper to get a Logger object and print messages to your heart's content. Here is some example code: Put this in the class declaration: private static java.util.logging.Logger serverLogger = LoggingHelper.getServerLogger(); Use these throughout your code: serverLogger.log(Level.INFO, "Hello World!"); serverLogger.wa...

Every now and then my job gets so boring that I feel like a robot. Today was one of those days, so I decided I needed a laugh and went in search of funny quotes relevant to working as a corporate sys admin... Hopefully there's one or two new ones for readers. The man who smiles when things go wrong has thought of someone to blame it on. -Robert Bloch UNIX is basically a simple operating system, but you have to be a genius to understand the simplicity. -Dennis Ritchie Doing it right is no excuse for not meeting the schedule. -Plant Manager, Delco Corporation Some things Man was never meant to know. For everything else, there's Google. -Unknown To err is human... to really foul up requires the root password. -Unknown Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots... -Rich Cook I had a fortune cookie the other day and it said: 'Outlook not so good'....