Technical FAQ: WebLogic Server-related questions
FAQ Index
Problem setting time zone to China Taiwan Time (CTT)
I set the time zone in my
environmnent to China Taiwan Time (CTT) but the WebLogic Server log
reports that the time zone is Central Standard Time (CST). What's
wrong?
This is a bug in the JDK
confirmed by JavaSoft. The bug causes the WebLogic
Server log to erroneously report that it is using CST instead of CTT
although the actual time conversion is correct. There is currently no
workaround, but JavaSoft reports that this bug is fixed
in JDK 1.2.
Using SOCKS with WebLogic
I am experiencing problems trying to connect from behind a
firewall/proxy installation at client sites. Is there any way to
configure WebLogic to use a SOCKS proxy?
You can configure a java.net socket to use SOCKS by setting a Java
system property. For details, see How do I
make Java work with a proxy server?. Once the property is set,
WebLogic's socket connections will use the SOCKS proxy.
Can I speed up connection requests?
We recently installed a WebLogic Server, and found that it
seems to take 15-30 seconds to respond to connection requests, even when
there is no significant load. How can I speed up connection delays?
Connection delays are often caused by DNS problems. WebLogic performs
a reverse lookup on the hostname from which a new connection is
made. If the DNS reverse lookup is not working properly because the
connection is coming from some kind of proxy server, it could be
responsible for the delay. You might want to work with your system
administrator to determine whether DNS and the third-party networking
software are working properly. Try writing a simple server program
that performs a reverse lookup on any connection made to it. If that
lookup is delayed, then you know that the proxy server is the source
of the problem.
Does WebLogic use CORBA? Is it an ORB?
What kind of information can you give me about WebLogic's CORBA
support? How can CORBA clients communicate with the WebLogic Server via
IIOP?
"CORBA"
support means many things to many people. Most frequently, it seems
to mean simply IIOP
/ORB
support and not much on CORBA services. WebLogic
supports CORBA in multiple ways.
First, Java clients can tunnel through a CORBA environment to a
WebLogic Server. We call this "IIOP tunneling," and it is intended for
use with applets coming through an IIOP firewall, such as the IONA
Wonderwall product. This is a Java-to-Java model riding over an IIOP
communications framework.
A second WebLogic feature is a CORBA gateway provided with the
WebLogic Server. It supports pure CORBA clients of any language using
either the WebLogic Remote
or WebLogic Events
services. WebLogic offers an RPC programming model, and it can be
used to proxy any of the other WebLogic services for the CORBA
client. We provide an IDL
to facilitate this integration, and we support VisiBroker in this
model. WebLogic Events is supported for CORBA clients, allowing
clients to submit and receive asynchronous WebLogic Events.
WebLogic Enterprise Connectivity gives you the ability to create IIOP
connection pools to a BEA WebLogic Enterprise, allowing you to execute
WebLogic Enterprise CORBA objects from WebLogic Server servlets and
Enterprise JavaBeans.
We cannot currently support CORBA connectivity with Java 2 version 1.2,
due to class conflicts with Java 2 CORBA support.
Which WebLogic classes do I need to jar up for my client app?
I'm preparing to deploy my WebLogic client application, and I want
to separate out those classes that the client will not need. How
do I do that?
It depends on what your client application does. The easy
answer is to jar everything in the weblogic/classes
directory, as well as the weblogicaux.jar shipped in the weblogic/bin
directory.
If your client is a Java application or applet
, you may be able to be
more selective about which classes you ship to your client. You can
use one of the utilities to help
you.
The best solution is to use WebLogic ZAC. ZAC (Zero Administration Client) lets you publish
your client application for automagic installation on your client
machine. ZAC includes features for generating a tiny bootstrapping
application that a client can download.
It automatically contacts the publishing WebLogic Server to install
the client application and then updates it automatically whenever you publish
changes.
Speeding up HTTP tunneling
HTTP tunneling is slow! How can I speed it up?
Unfortunately, there is a significant performance hit when using HTTP
tunneling.
We hav optimized it somewhat, but because everything is
encapsulated in HTTP, it is slower than non-secure communications. We
continue to look for ways to optimize our implementation.
Be sure that you really need to use HTTP
tunneling. For example, if your firewall can pass IP
packets through port 80, you can use the fast t3 protocol on port 80.
If you must use HTTP tunneling to go through a firewall, http://www.socks5.com/ has a product
that performs better than HTTP proxies.
Using Netscape security certificates with WebLogic
I have a Netscape security certificate in
ServerKey.der. How do I obtain just the private key?
Netscape stores the private and public keys together in
a key-pair file, which prevents you from separating the
public and private keys. In weblogic.properties, the property entry
[weblogic.security.key.server] refers only to the Private Key file.
Therefore, you must generate another request for a
certificate, not using Netscape utilities. You can use the
Certificate Request servlet to generate a request for a new certificate.
Using WebLogic SSL
shows how to use the servlet.
Starting the WebLogic Server automatically with a UNIX boot
How do I set up the WebLogic Server to execute whenever I reboot the UNIX server?
You can add a startup script to your UNIX rc scripts to run the
WebLogic Server at UNIX boot time. Here is an example from an HP-UX
11 system, running under JDK 1.1. You need to supply the URL for your WebLogic Server
and your system password. This
file, wlstart, is placed in
the /sbin/init.d directory and
there is a link to it in the /sbin/rc2.d directory:
export SHLIB_PATH=\
/home/user1/weblogic/lib/hpux11:/oracle/8.0.4/lib
export CLASSPATH=/home/user1/weblogic/classes:\
/home/user1/weblogic/lib/weblogicaux.jar
export ORACLE_HOME=/oracle/8.0.4
export ORACLE_SID=DEMO
export ORACLE_TERM=vt100
export QAT=/home/user1/weblogic
cd $QAT
PATH=/sbin:/usr/sbin:/usr/bin:/opt/java/bin
export PATH
case $1 in
'start')
java -ms64m -mx64m -verbosegc weblogic.Server > \
/home/user1/weblogic/server.out 2>&1
;;
'stop')
java weblogic.Admin URL shutdown system password
;;
*)
echo "usage: $0 {start|stop}"
;;
esac
You should work with your UNIX system administrator to set up scripts similar
to this for your system.
Servlet performance seem a big sluggish on your NT machine?
I'm serving several HTTP servlets over my internal network. Sometimes
they are really fast, while at other times the performance seems
sluggish. There doesn't seem to be a correlation with actual clients
or even network traffic. From the local machine itself, the response
time is very fast. Very mysterious. Any ideas?
As it turns out, we have seen such mysterious behavior ourselves, and we
finally tracked it down to something completely unrelated to the
network or client usage: response time for a servlet
is about 5 times slower when you are running a screen saver on the
machine, particularly for the OpenGL screen savers. You might try
turning off your screen saver and see if that helps!
"NoClassDefFound" / "Too many open files" errors on Solaris
I'm using WebLogic Server on Solaris. When I try to run my
application, I get a "NoClassDefFound" error, although I can see that
the class causing the error does exist and is in the right
directory. In fact, there are other classes in the same directory that
are getting loaded. What's the problem?
I'm using WebLogic Server on Solaris. When I try to run my
application, I get a "Too many open files" error. What's the problem?
We have seen this situation when the user account runs out of file
descriptors. On Solaris, each user account has a certain limited
number of file descriptors. You can find out how many file descriptors
you have with the limit
command in csh.
You can increase file descriptors if you have enough
privileges with the ulimit
command in the csh. Otherwise, ask your system
administrator to increase the file descriptors available to your
processes.
Another solution is to create a .jar file with all of the WebLogic
classes, since a .jar file only requires a single file descriptor.
I can't get the WebLogic Server to start
When I try to start the WebLogic Server, I get a "Fatal Error: Cannot
open d:\weblogic.properties" message. I've installed the WebLogic:
classes in a directory in my CLASSPATH. What is the weblogic.properties file, and why can't the WebLogic
Server find it?
The weblogic.properties file
contains configuration information for your WebLogic Server
environment. It is shipped in your distribution kit. Unless you use
InstallShield under
Windows NT/95, you must edit the properties file before you try to
start the WebLogic Server, to set host, port, system password, and
other WebLogic Server configuration information. For more on the
properties file, see Setting
WebLogic properties. Once edited, the
file should be placed in your weblogic/ directory, along with a subdirectory called
"myserver".
When you start the WebLogic Server, it looks first for the properties
file in the current directory, and then it checks the path you supply
on the command line as weblogic.system.home.
You can cd to the directory
containing your weblogic.properties file and start the WebLogic Server
with the command
line example described in Setting up and Starting the WebLogic Server.
Or, if you prefer, you can start the WebLogic Server from any
directory using the -D option to set weblogic.system.home. For example, if you have installed
the properties file in the directory d:\net\weblogic\weblogic.properties, add this to the command line
example:
% java ... -Dweblogic.system.home=d:\net\weblogic\ ...
Startup scripts
are provided in the distribution. You can customize these scripts for
your system. There are complete instructions on setting up, running,
and managing the WebLogic Server in the Administrator Guide,
Managing the WebLogic
Server.
Problems with the WebLogic Server running out of memory
When I run the WebLogic Server, it runs out of memory very quickly. How
do I fix this?
I'm using the WebLogic Server for a large number of client connection
requests, and occasionally there are memory problems. How can I remedy
this?
Increase the allocation of Java heap memory
for the WebLogic Server. (Both the minimum and the maximum should be
set to the same size.) Start the WebLogic Server with the
-ms32m option to increase the allocation, as in this example:
$ java ... -ms32m -mx32m ...
This allocates 32 megabytes of Java heap memory to the WebLogic
Server, which improves performance and allows the WebLogic Server to
handle more simultaneous connections. You may increase this value if
necessary. See the administrator guide, Tuning the
WebLogic Server, for more details.
Running WebLogic with Microsoft SDK for Java
I downloaded your software and tried unsuccessfully to run your
WebLogic Server against my installation of Microsoft SDK for Java. Why
doesn't it work?
You can run the WebLogic Server with Microsoft SDK for Java, version 3.2.
The
corresponding Microsoft SDK For Java version is 5.00.3167.
Instructions for starting the WebLogic Server using JView are
available in Setting up and starting the WebLogic Server.
Problems running WebLogic under Symantec?
I'm having some problems running the WebLogic Server under some
versions of Symantec's Java. Why is this?
We have had some reports of difficulties with Symantec's Java,
including GPFs when trying to run the WebLogic Server. Please use one
of the JDKs we have certified, listed on our Platform support page.
The WebLogic Console is
reporting incorrect hostname and IP address
On the Server tab in the WebLogic Console, when I connect to myserver,
"loopback" and "127.0.0.1" are displayed. How can I get the correct
information displayed?
There is a bug in some VMs that does
not correctly read the host name when "localhost" is is the first
entry in the hosts table. As a workaround, ask your system
administrator to move "localhost" from the top position of the hosts
table (/etc/hosts on UNIX) and
then restart WebLogic Server.
What are the java.io exceptions in the log file?
I see messages like these in the log file:
-
| (Windows NT) |
java.io.IOException Connection Reset by Peer
java.io.EOFException Connection Reset by Peer |
| (Solaris) |
java.io.Exception: Broken pipe |
What causes these messages?
These messages occur when you are using Servlets, a client initiates
an HTTP request, and then performs a series of actions on the browser:
- Click Stop or enter equivalent command or keystrokes
- Click Refresh or enter equivalent command or keystroks
- Send a new HTTP request.
The messages indicate that WebLogic Server has detected and recovered
from an interrupted HTTP request.
