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This article mainly introduces the relevant knowledge of "what are the WebSphere interview questions". The editor shows you the operation process through actual cases, and the operation method is simple, fast and practical. I hope this article "what are the WebSphere interview questions" can help you solve the problem.

1. What is Ripplestart?

Ripplestart is used to restart the WAS cluster. It first stops JVM, and then starts it. By performing ripple startup, you can ensure that only one JVM is closed at a time, so it does not cause the application to shut down.

For example, you have five JVM in the cluster, and when you start the ripple, it stops the JVM1 and starts the JVM1, and then stops the other JVM in the cluster.

two。 What do you do when JVM consumes 100% of CPU and memory on the server?

First, determine which JVM has the highest utilization. Thread dump the identified JVM for investigation, and then restart JVM as a solution to cool CPU / memory.

3. What is node synchronization?

IBM WAS stores the entire configuration in a central repository called the main repository, and each node will have a local repository.

When you make any changes to a node through DMGR, you must synchronize it, so configure the server that will be pushed to the appropriate node.

Synchronization always occurs from the primary database to the local repository, so it is an one-way communication.

4. If DMGR drops, will the application work properly?

Yes, the drop in DMGR will not affect existing running applications. However, if you need to make any changes or deployments through DMGR, that will be affected.

5. How do I deploy an application in WebSphere?

There are three possible ways to deploy.

Hot deployment-copy the application files to the application directory. This is useful for non-production environments and is not recommended in production environments.

DMGR-you can deploy applications through DMGR by going to applications > > New applications

Scripts-you can develop wsadmin scripts or ant tasks to deploy the application.

6. Why does the JVM appear automatically when I stop / terminate the process manually?

There could be two things.

Automatic restart is enabled for JVM, which is the default and is available under the JVM > > monitoring policy.

If this is not the case, there may be a script in cron that checks for the process and starts it if it cannot be found.

7. Which file types can you deploy to WebSphere?

You can deploy WAR,EAR,JAR or SAR modules through the DMGR console or script.

8. What is a virtual host?

Virtual hosts contain multiple URL (based on IP or FQDN) on a single application and are configured through the WAS management console.

In order to allow access to the application on a specific URL, you must have the URL in the virtual host and associate it with the application.

9. How do you deal with customers' slow application complaints?

The slow speed can be caused by a variety of reasons, so it is necessary to determine whether the slow speed comes from WebSphere or other components. To isolate, you can check the following.

Is this slow for all users?

Is the whole application slow or just some functions?

How about accessing JVM URL directly (bypassing the Web server)?

If you find that it is running slowly in JVM, you can dump it and check the log to find out why. It is worth checking to see if there is any release, and is slow after that.

10. How do I backup my WAS configuration without stopping DMGR?

Go to the DMGR configuration file and bin folder

Execute. / backupConfig.sh-nostop for backup

11. What is the default WAS port?

The default ports for HTTP are 9080 and HTTPS9443. For more information, see the default Port page.

twelve。 What versions of WebSphere are available?

WAS-Network deployment WAS-developer WAS-z / OS WAS-Hypervisor WAS-Fast WAS-basic WAS-Free Core

13. How do I generate and propagate plug-ins?

(1) Log in to the WAS Management console

(2) go to Server > > Web Server

(3) Select the server, and then click the "generate" and "propagate" buttons

14. What common problems have you encountered?

Here's an idea for you:

Virtual host is not defined

The log does not move.

Internal server error

Out of memory exception

Slow

JVM failed to start

High CPU / memory / disk utilization

15. How do I check the installed version of WAS?

Go to the profile and bin folder

Execute. / versionInfo.sh

16. How do you know if your JVM is started?

There are several ways to confirm this.

Do you have any monitoring tools, and if so, check for alerts or current status

Log in to the server via ps-ef | and use grep for JVM. Grep jvmname

Check if you can access JVM URL

Check to see if telnet JVM URL and port are available

Check if the JVM port is listening on the server

Use the serverStatus.sh-all command to view what is running

17. Can you tell me some log files generated by WebSphere?

SystemOut.log SystemError.log native_stdout.log native_stderr.log

18. How do I generate thread dumps?

There are three possible ways to generate thread dumps.

(1) from the DMGR console: go to troubleshooting > > Select JVM and click Java core

(2) kill JVM's-3 PID

(3) use wsadmin.sh

19. What is the difference between vertical clusters and horizontal clusters?

The members of a vertical cluster are on the same node or server, while a horizontal cluster spans multiple nodes and servers in a cell.

20. What is garbage collection?

Garbage collection is a memory management process that automatically releases objects that are no longer used by the program.

21. How do I disable security in WebSphere?

You can disable security by executing "securityoff" through wsadmin.sh. After turning off security, you must restart DMGR.

twenty-two。 How do I enable detailed garbage collection?

Verbose GC is not enabled by default, and if necessary, you can do it in the following ways:

Server > > Server Type > > WebSphere Application Server under Java and process Management, select JVM > > process definition Click the Java virtual machine under other Properties, and then select the detailed garbage collection check box

23. How do I make WebSphere start automatically when the server reboots?

WebSphere automatically generates a startup script in / etc/init.d, which ensures a restart at startup.

However, if for some reason no script exists, you can create a script and place it under / etc/init.d and enable it as shown below.

Chkconfig-add WebSphere # script file namechkconfig WebSphere on

24. How to increase the heap size of JVM? (1) Log in to the administrative console

(2) go to Server > > Server Type > > WebSphere Application Server

(3) Select JVM > > process definition > > Java virtual machine

You can enter the initial and maximum heap size here.

25. Is it possible to synchronize nodes when nodeagent is off?

Absolutely, nodeagent must be stopped for synchronization to work.

twenty-six。 What are the commands to stop and start DMGR,Nodeagent and JVM?

Stop it

JVM-stopServer.sh JVMNAME Nodeagent-stopNode.sh DMGR-stopManager.sh

Start

JVM-startServer.sh JVMNAME Nodeagent-startNode.sh DMGR-startManager.sh

twenty-seven。 What are the new features of WAS 8.5.5?

At a high level:

Java SE 7 supports HPEL record built-in health management free profile intelligent routing dynamic clustering JDBC 4.1 cluster Web 2.0 support

twenty-eight。 What does node federation mean?

The federation in WebSphere means adding nodes to the cell. This is done through the addNode.sh command, which may take several minutes, depending on the size of the node.

twenty-nine。 What is FFDC?

FFDC (first failure data capture) captures events and errors during the WebSphere runtime. FFDC data can be useful for analyzing problems, and IBM support personnel usually ask if there are any problems.

thirty。 Can you decode the WebSphere KeyStore XOR?

Yes, you can use online tools

thirty-one。 What is the default scripting language in WebSphere? JACL or Jython?

JACL is the default scripting language in WebSphere.

thirty-two。 How do I apply fix packs in WebSphere 8.5.x?

You can use IBM IM to apply this fix. For detailed instructions, see how to apply the fix pack guide.

thirty-three。 Where is your Web server hosted?

Explain the supported application architecture again. However, in a typical production environment for Internet applications, the Web server will be in the DMZ and the application server will be in the core network.

This means that you must allow the necessary ports in the firewall between the Web server and the application server.

thirty-four。 What is conversational affinity?

In other words, session affinity is a persistent session. Session affinity allows a request to be bound to a single JVM. This means that the returned request will always be routed to the same JVM.

thirty-five。 Can you deploy multiple applications in a single JVM?

Yes, as long as the context root of each application is unique, multiple applications can be deployed on a single JVM.

thirty-six。 Which database do you use Websphere with?

Tell them what you use. Most organizations use Oracle databases, but WebSphere also supports the following databases. DB2 Oracle Database Microsoft SQL Server Sybase

thirty-seven。 How do I connect the Web server to the WAS?

There are two ways to connect to the WAS.

(1) use plug-ins-this is the recommended way to install WAS plug-ins on Web servers.

(2) use ProxyPass-if you are using Apache and do not want to use plug-ins, you can connect to WAS JVM through the ProxyPass directive.

thirty-eight。 Do I need a Web server before WAS?

It is recommended to support Web server before WAS to improve security, performance and maintainability.

thirty-nine。 What is a cell?

A cell is a logical group of nodes that can have one or more nodes. Clusters and all clusters are managed through an administrative console.

forty。 What is the default session timeout for the administrative console?

30 minutes

forty-one。 What is a fix pack?

A fix pack is a collection of patches provided by IBM. It may include bug fixes, security patches, and performance improvements.

forty-two。 What registry or repository does WebSphere support?

Federated repository local operating system independent LDAP registry independent custom registry

forty-three。 What is a shared library?

It is recommended that you create shared libraries to reduce duplicate library files. A single shared library can be used by multiple applications in a cell.

forty-four。 What is the context root?

The context root of each application should be unique within that cell. It defines n deployment descriptors for accessing the application.

For example, if the context root of application An is called "retail", the application can be accessed from http:// servername:port / retail

forty-five。 What is the WAS plug-in configuration file name?

WebSphere plug-in configuration name is plugin-cfg.xml

forty-six。 How to change the size of the WebContainer thread pool?

You can change the WebContainer thread pool by going to JVM > > thread pool > > WebContainer.

forty-seven。 Can you change the context root of the deployed application?

Yes, it's feasible. To do this through the administrative console, enter the application and click context Root of the Web Module to change the context root.

JVM must be restarted after the change.

forty-eight。 Which script can change the Java SDK used by the configuration file?

The managesdk.sh script is available in the bin folder, which will help you change the SDK.

forty-nine。 What is PMT?

PMT (profile Management tool) is the GUI used to create and manage WebSphere profiles.

This is the end of the introduction of "what are the WebSphere interview questions"? thank you for your reading. If you want to know more about the industry, you can follow the industry information channel. The editor will update different knowledge points for you every day.

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