Oracle Weblogic Server – Version: 9.0 and later   [Release: and later ]
Information in this document applies to any platform.

Goal

There are several files with a .lok extension in the WebLogic Server (WLS) domain directory. What are these files used for?

Solution

There are config.lok, EmbeddedLDAP.lok and XXXserver.lok files which are used by the admin server and managed server. Another lock file named edit.lok is used for the admin server only. Here are some more details on each:

• config.lok
  The config.lok file is just used for getting a file lock on the config.xml file, in order to ensure that config file updates run serially. It will not cause any problems if it exists in the directory.
• edit.lok
  The edit lock is used to ensure that only one user at a time is editing the configuration. The edit lock is only used on the Admin server.
• EmbeddedLDAP.lok
  This file locks access to the embedded LDAP server, in order to ensure that only a single process has access to this directory server. if two processes write to the same directory server, the directory server will have a problem.
• XXXServer.lok
  The [server name].lok indicates that the server with name [server name] is running. This is used to prevent a server from being booted twice. If you are sure that this server process is shut down, you can delete it.

JD Edwards EnterpriseOne Tools – Version: 8.98 to 8.98 – Release: 8.98 to 8.98
Information in this document applies to any platform.

Goal

You have WebLogic Server installed as your Application Server.   You want to install a Web Dev client and want to know if there is a local WebLogic web server for the HTML client or not.

Solution

The only option is currently OC4J.  Installing IBM WebSphere Express on WebDev client is not compatible with Oracle WebLogic as the JAS/Web server.

You should not use IBM WebSphere Express because it uses IBM JDK.  When you generator serialized objects,  it will generate incompatible serialized specs because of the JDK mismatch.  The generator JVM must match with the server JVM. There is a caveat if you chooses to use JRockit JVM for Weblogic.

So you should install OC4J and change the JDK to a matching 1.6.x JDK.   Refer to Note 1086577.1  JD Edwards EnterpriseOne Tools 8.98 Update 3 Oracle WebLogic Server 11g Certification, where Appendix A Generating JD Edwards EnterpriseOne Serialized Objects states:

To generate objects using an Oracle WebLogic application server, you must use JDK Version 1.6 on the client machine. Additionally, you must modify the gen_oas.bat file on the client machine to point to the location of your JDK Version 1.6.

References

NOTE:1124186.1 – E1: WAS: Where to Download Websphere Application Server 7.0 Express for WebDev Client and Generation Machine
NOTE:705409.1 – JD Edwards EnterpriseOne Tools 8.9x Minimum Technical Requirements for Clients

Oracle Weblogic Server – Version: 8.1 to 10.3.3
JDBC – Version: 10.1.0.2 and later    [Release: 10.1 and later]
Information in this document applies to any platform.
This document is applicable for all versions of WebLogic starting from WLS 8.1 and later all service packs on all supported platforms running with Oracle database.

Goal

WebLogic – How to enable Oracle JDBC Driver Debug in WLS?

Solution

Please follow below steps for enabling Oracle JDBC Driver Debug in WebLogic.

1) Download the Oracle JDBC driver debug jar from the Oracle download site listed below. Debug Driver jars will have “_g” at the time end of the filename. For eg. ojdbc14_g.jar is for WebLogic 8.1:

http://www.oracle.com/technetwork/database/enterprise-edition/jdbc-10201-088211.html

2) Add the downloaded oracle driver debug jar to very beginning of the classpath of the WebLogic startup scripts.

3) Enable JDBC Debug flags from console for the server instance.

4) Create OracleLog.properties file with content below on the file system where the WebLogic server is running and give it read/write permissions.

5) Once you create the  properties file above add the arguments below to WebLogic startup script .

For eg: if you want OracleLog.properties inside /tmp directory and want to cretae JDBC driver debug log with file name JDBCDebug.log under /tmp directory then your command line option will look like below.

6) Once you add the driver debug flags above to the startup script restart the WebLogic server instance. You should be seeing JDBC Driver debug log file with specified filename created inside specified directory location.

Below will be snippet of Oracle Driver debug information inside JDBC Driver debug log.

NOTE:

Enabling JDBC Driver debug flags is verbose as it prints lot of debug information. Logging levels can be changed to different properties as FINE, SEVERE, FINEST, INFO etc. based upon the debugging requirement.

References

http://www.oracle.com/technetwork/database/enterprise-edition/jdbc-10201-088211.html

Oracle Weblogic Server – Version: 8.1 and later   [Release: and later ]
Information in this document applies to any platform.

Goal

Is it possible to have a WebLogic Server domain where different managed servers are running different versions of WLS? For example, can some managed servers be running WLS 10.3.3 and other managed servers running 10.3.0?

Solution

No, that is not possible. All servers in a cluster must be at the same major, minor, and patch set version. Below is the documentation which has information on this. Please refer to “Compatibility Within a Domain” section.

http://download.oracle.com/docs/cd/E14571_01/web.1111/e14529/compatibility.htm

Only during the rolling upgrade process would you have servers at two different patch set levels in a cluster, and we expect the rolling upgrade process to complete within a few hours. This process is for upgrading a running WebLogic Server cluster with a patch, maintenance pack, or minor release without shutting down the entire cluster or domain. During the rolling upgrade of a cluster, each server in the cluster is individually upgraded and restarted while the other servers in the cluster continue to host your application. Below is the documentation which has information on this.

http://download.oracle.com/docs/cd/E14571_01/web.1111/e13754/rolling_upgrade.htm#i1065782

References

http://download.oracle.com/docs/cd/E14571_01/web.1111/e14529/compatibility.htm
http://download.oracle.com/docs/cd/E14571_01/web.1111/e13754/rolling_upgrade.htm#i1065782

Oracle Weblogic Server – Version: 6.1 to 8.1
Information in this document applies to any platform.

Purpose

Problem Description

The load balance of HTTP requests among WebLogic cluster nodes is uneven, i.e., one or more nodes in cluster are receiving and executing more HTTP requests than the other nodes in same cluster.

Problem Troubleshooting

Please note that not all of the following items would need to be done. Some issues can be solved by only following a few of the items.

Last Review Date

May 4, 2010

Instructions for the Reader

Troubleshooting Details

Why does the problem occur?

The problem of uneven load balancing of HTTP requests in a cluster can be characterized as:

Uneven load-balance of HTTP requests due to uneven distribution of HTTP sessions

The proxy forwards requests without any session cookie to a cluster node based on a round-robin load-balancing scheme and a new session is created on that node. Ideally all cluster nodes should receive an equal share of HTTP sessions. When that does not happen, nodes with more sessions get more volume of requests than other nodes because of the “sticky” load-balance policy. The net result is uneven load distribution among cluster nodes.

Requests with a session cookie are always forwarded to the node that is the “primary” host of the session, which is called sticky load-balancing or session affinity based load balancing. The investigation of uneven load balancing does not apply to this type of request.

A request with session cookie will have log entries like below in proxy debug log:

The plug-in maintains an in-memory list called the “General Server List” which is the list containing cluster nodes known to be in good health (Status: OK) at any point of time. The plug-in uses the General Server List to determine which cluster node to choose in order to forward a request without a session cookie. If there is no problem, the General Server List will be same as the Static List that is configured with the plug-in.

There are some conditions (as described below) that will cause the General Server List to shrink and become a subset of the Static List. When that occurs, there will be fewer nodes available to which the plug-in will forward requests without any session cookie and thus distribution of HTTP sessions will be uneven.

Factors that affect General Server List

• X-WebLogic-Cluster-List HTTP header in the response stream from a cluster node that services a particular request.
  What is X-WebLogic-Cluster-List HTTP header?
  The backend weblogic server that processes a request from plug-in, returns the list of live cluster members known to it at that point via a HTTP header X-WebLogic-Request-ClusterInfo in the response stream. The header will be returned only if there is a change in cluster list.

  If the returned cluster list is truncated, then the plug-in’s General Server List will also become subset of the full cluster list. The backend cluster node will return a truncated list when it has a subset of cluster nodes in its own cluster view.

  This is the most common cause of load-balance problems.

• Any Exception that has occurred when the plug-in attempts to get a request serviced by a cluster node, i.e., when sending the HTTP request to a cluster node or when reading the response from it.

  If any Exception occurs in this process, the cluster node will be marked bad and will be taken out of General Server List temporarily.

Diagnosis

1. Configure the proxy plug-in to produce additional diagnostic data. Refer to General Diagnostic Process for Problems with WebLogic Server (WLS) Proxy Plug-in Support Pattern (Note 780007.1) for details.
2. Look at the proxy bridge page for General Server List

   If the list does not show all the cluster nodes with Status: OK, then the General Server List has been truncated to contain a subset of nodes.

   Original:
   General Server List:

   1. Host: '172.18.137.50' Port: 8001 Status: OK
   2. Host: '172.18.137.54' Port: 8001 Status: OK

   Truncated:
General Server List:
1. Host: '172.18.137.50' Port: 8001 Status: OK

3. The next step is to identify which factors, (a) or (b), or a combination of both, contribute to the problem.
   • Truncated X-WebLogic-Cluster-List

     Search for X-WebLogic-Cluster-List in proxy log and see at what point a truncated list has been returned from backend cluster node. Determine which backend cluster node has returned the truncated X-WebLogic-Cluster-List by following the preceding log entries for the same request.

     Full cluster list:
     Mon May 10 13:14:30 2004 Hdrs from WLS:[X-WebLogic-Cluster-Hash]=[sUuYnuyhFpkhw6ty44bkNczWnaA]
     Mon May 10 13:14:30 2004 Hdrs from WLS:[X-WebLogic-Cluster-List]=[-2032354160!-1408071374!38625!-1|-457294087!-408071370!38625!-1]
     ...
     Mon May 10 13:14:30 2004 Parsing cluster list: -2032354160!-1408071374!38625!-1|-457294087!-1408071370!38625!-1
     Mon May 10 13:14:30 2004 Initializing lastIndex=0 for a list of length=2
     Mon May 10 13:14:30 2004 ### Got a new Server List of length 2 ###
     Mon May 10 13:14:30 2004 ###Response### : Srvr# [1] = [172.18.137.50:38625:65535]
     Mon May 10 13:14:30 2004 ###Response### : Srvr# [2] = [172.18.137.54:38625:65535]

     Truncated cluster list:
Tue May 11 12:22:01 2004 Hdrs from WLS:[X-WebLogic-Cluster-Hash]=[O2ukNQEbMOLzU+R2026DpZaYVtI]
Tue May 11 12:22:01 2004 Hdrs from WLS:[X-WebLogic-Cluster-List]=[848189891!-1408071374!38625!-1]
...
Tue May 11 12:22:01 2004 Parsing cluster list: 848189891!-1408071374!38625!-1
Tue May 11 12:22:01 2004 Initializing lastIndex=0 for a list of length=1
Tue May 11 12:22:01 2004 ### Got a new Server List of length 1 ###
Tue May 11 12:22:01 2004 ###Response### : Srvr# [1] = [172.18.137.50:38625:65535]

   • Exception in request-response

     Look for “Exception objects created” under “Runtime statistics” on the proxy bridge page. If the count is greater than 0, then some exceptions have occurred.

     Also look for “Exception” in the proxy log.

     Proxy bridge page after an error:
     requests: 6
     Exception objects created: 1
     CONNECTION_REFUSED exceptions: 1

     Corresponding log entries in proxy log:
Tue May 11 12:22:00 2004 attempt #0 out of a max of 5
Tue May 11 12:22:00 2004 trying connect to PRIMARY '172.18.137.54'/38625 /65535 at line 1138 for '/mywebapp/session.jsp'
Tue May 11 12:22:00 2004 INFO: New NON-SSL URL
Tue May 11 12:22:00 2004 *******Exception type [CONNECTION_REFUSED] (172.18.137.54:38625 errno = 0) raised at line 1536 of URL.cpp

Resolution

• If the problem is found to be X-WebLogic-Cluster-List returning truncated list, then find out which cluster node had returned that response and focus on that node. Most often the problem is due to Multicast causing instability in cluster. See the Multicast Errors Support Pattern (Note 1092037.1) for a diagnosis of the multicast problem.
• If some exceptions are reported by bridge page, find out what type of exceptions have occurred.

  If the problem could not be resolved, because one or both of the above factors continue to affect the General Server List, then you can set DynamicServerList=”OFF” so that the General Server List will always contain the full list of cluster nodes as configured in the Static List. For details, refer to General Parameters for Web Server Plug-Ins and look for description of DynamicServerList. But pay attention to the implications of setting DynamicServerList=”OFF”

External Resources

General Parameters for Web Server Plug-Ins

How the plug-in handles failover:

• Apache plug-in: http://download.oracle.com/docs/cd/E13222_01/wls/docs81/plugins/apache.html#113634
• Microsoft IIS plug-in: http://download.oracle.com/docs/cd/E13222_01/wls/docs81/plugins/isapi.html#103628
• SunOne/Netscape plug-in: http://download.oracle.com/docs/cd/E13222_01/wls/docs81/plugins/nsapi.html#114841

Need further help?

If you have followed the pattern, but still require additional help, you can:

1. Query the My Oracle Support knowledge base using “load balancing plug-in,” as an example, to discover other published solutions.
2. Ask a more detailed question at the My Oracle Support Oracle WebLogic Server Community. Click on the Community tab to find the community.

If this does not resolve your issue and you have a valid support contract, you can open a support request by logging in at My Oracle Support.

Oracle Weblogic Server – Version: 8.1 to 10.3.2
Oracle WebLogic Integration – Version: 8.1 to 10.3

Symptoms

WebLogic Server is running out of memory after while the server running for a longer period of time like a day or two. Servers were load tested and configuration was finalized after several capacity planning tests.

EXPECTED BEHAVIOR
Out of Memory shouldn’t happen in production. Regular GC runs should keep the free memory available.

Cause

The issue is caused using development mode in production environment

Development mode will make server to cache the runtime information to support debugging, workshop test console and also debug logging will be enabled to support development. All of these contributes to lot of memory consumption, but in production this doesn’t scale to perform better. Hence switching to production mode helps achieving optimum results from WLS servers.

Also “java -client weblogic.Server” will be used to launch the servers instead of “java -server”. java -client is not optimal configuration for servers

Solution

Production WLI server is running in Development mode. Development mode is not optimized for production servers.

It is suggested to use production mode in production environments. To change the Server mode to production, please use the following steps:

1. Open WLI domain’s setDomainEnv.cmd and search for “set PRODUCTION_MODE=” and assign the value “true”.

2. Three other flags debugFlag, testConsoleFlag and iterativeDevFlag will be turned to false by the
script in the further lines of code in setDomainEnv.cmd

References

http://download.oracle.com/docs/cd/E13226_01/workshop/docs81/doc/en/workshop/reference/commands/cmdStartWebLogicCommand.html
http://download-llnw.oracle.com/docs/cd/E13160_01/wli/docs10gr3/

Oracle Weblogic Server – Version: 9.0 to 10.3

Goal

The MBean Browser JManage has issues with showing and updating WLS Mbeans in WLS versions starting from 9.0 and later.

Solution

- The project home page of the free project is: http://www.jmanage.org/

- The MBeanBrowser can be downloaded here: http://sourceforge.net/projects/jmanage/files/
- The current non-Alptha- Beta-RC-version is 1.0.4.
* jmanage-1.0.4.tar.gz = the product
* jmanage-1.0.4-wl9-patch.zip = the patch needed for all WLS 9.X based installations.

- Always install the product with the WLS related patch in order to get the Browser running under WLS9.* and later.

- If there are any issues let, turn on debug output according to the FAQ:

http://www.jmanage.org/wiki/index.php/JManage_FAQ#How_do_I_debug_jManage_code.3F

Please note – the use of this product is not supported by Oracle Global Software Support.

Oracle Weblogic Server – Version: 8.1 to 10.0
Information in this document applies to any platform.

Goal

How do I upgrade my license file from WLS 8.1 SP2 to WLS 8.1 SP6?

Solution

No license upgrade is needed when upgrading service packs. You can use the same license file.

For example, the license file need not be updated when upgrading from:

• WLS8.1SP2 to WLS8.1SP6
• WLS9.2 to WLS9.2MP2
• WLS10.0 to WLS10.0MP1

When upgrading from from one major version to another (for example, WLS8.1 to WLS9.2 or WLS9.2 to WLS10.0), you will need an updated license file. Please see How Can I Get a New WebLogic Server License? Note 842520.1 for more details.

References

NOTE:842520.1 - How Can I Get a New WebLogic Server License?

Oracle Weblogic Server – Version: 10.0
Information in this document applies to any platform.

Goal

What is the meaning of the following message in the WebLogic Server logs?

Solution

When you have a low-strength client connecting to a high-strength server (domestic build), the SSL
spec requires that security drop to the lowest common denominator. In order to do this, a second
low-strength cert/key is made in memory and then signed with your high-strength certificate/key
and used for that connection.
This is part of the SSL specification as well. Obviously, this can be time consuming and you do
not want to do it each time; therefore, WebLogic Server generates one on startup and will use it
500 times by default before regenerating it.
The 501st hit from a low-strength client will require the key to be regenerated; therefore,
incurring the key regeneration time.

<<End_of_Article>> FOLDER:ST.Middleware.AppServer.WLSConfigAndRuntime TOPIC:Core DOCUMENT-ID:887801.1 ALIAS: SOURCE:AWIZ 7776845.992 DOCUMENT-TYPE:HOWTO ZCXTECH TITLE:Need Explanation Of Error Message IMPACT:LOW SKILL-LEVEL:NOVICE STATUS:REVIEW_READY DISTRIBUTION:EXTERNAL ZCXCURRENT AUTHOR:SKAULWAR.US PRODID-5242 COMPONENT:WLSCORE.GENERAL MINVER:10.0 MAXVER: PORTID-0 FDRSEG-1283 FDRSEG-556 FDRSEG-557 FDRSEG-465

Oracle Weblogic Server – Version: 10.3
Information in this document applies to any platform.
This document is applicable to WebLogic Server (WLS) 10.3 GA (10.3.0) only. Earlier versions of WLS do not show the problem, and WLS 10.3.1+ is already fixed.

Symptoms

A java.lang.ClassFormatError is observed when using the Eclipse JDT compiler with WebLogic Server (WLS) 10.3 GA (10.3.0).

Previous releases of WebLogic Server would work without any problem. But on a WLS 10.3.0 domain, this kind of error occurs:

Cause

The Eclipse JDT compiler used in conjunction with WLS 10.3 GA has a bug when trying to compile classes to the JDK 6 format. This problem is addressed by bug 8177354, which forces the compilation to use the JDK 5 format instead.

Solution

Patches are available for bug 8177354:

------------------------------------------
     PATCH REPOSITORY INFORMATION
------------------------------------------
  WLS Version | Patch ID |  Passcode
--------------+----------+----------------
    10.3 GA   | HEH5     |  JW6PS6W4

Fixed in: 10.3.1

To apply one of these patches, download the patch using Smart Update and apply: see Note 885851.1 for step-by-step instructions. If your target system is offline, please refer to Note 876004.1 for additional assistance. All the details about SmartUpdate are available in the SmartUpdate documentation.

Patches are specifically tied to a particular release and maintenance pack of WebLogic Server (WLS). A patch for WLS 9.2.2, for example, very likely would not work on WLS 9.2.3. In a few cases, patches are also specific to particular operating systems. If you think you are experiencing the problem outlined in this note, but your WLS version is not included in the list of patches provided here, please contact support and ask for a version of the patch appropriate for you. Please reference this note as well as this bug number to help speed our service for you.

References

BUG:8177354 - [CR380619] WLS 10.3 - GETTING JAVA.LANG.CLASSFORMATERROR WHILE ACCESSING A PARTI