WAS important interview Questions part-2

1. What about master repository?

Ans: deployment manager contains the MASTER configuration and application files. All updates to the configuration files should go through the deployment manager.

2. Tell me IHS executable files, means bin directory files?

Ans: Apache, ApacheMonitor, htpasswd, htdigest, htdbm, ldapstash, httpd.exe

3. Why given the httpd.conf file to installation of plug-in?

Ans: identify the web server (port, virtual hosts) to configure the web server definition

4. How to configure remote system httpd.conf file?

Ans: select web server machine (remote)

5. Several types of log files in the appserver?

Ans: system out, system err, trace, native out , native err, activity.

6. websphere packages?

Ans: express, base, network deployment

7. What is the profile?

Ans: profiles are a set of files that represent a websphere application server configuration.

8. What is the trace?

Ans: A trace is an informational record that is intended for service engineers or developers to use. As such, a trace record might be considerably more complex, verbose and detailed than a message entry.

9. What is heap memory?

Ans: Objects storage space for objects references created at run time in a jvm is heap memory.

10. Out of memory exception is there, how to handle that exception?

Ans: To incrise heap memory size

11. What about IHS?

Ans: IHS (IBM HTTP Server) is one of the web servers. It serves the static content only and it takes up only http requests.

12. What about plug-in?

Ans: plug-in is one of the modules it is interface between application server and web server, the plug-in process receives the request from the client first. If the request is for dynamic content, the plug-in diverts the request to the websphere application server. If the request is for static content, the plug-in forwards it to the Http server.

13. What is the global security?

Ans: it provides the authentication and authorization for websphere application server domain (administration client or console).

14. How to configure the global security?

Ans: open console and then select security option in the right side menu, and then select localOs registry in the user registry, then enter the username, passwords. And again select global security then ltpa option then provide the password, then save the configuration. And restart the deployment server and then relogin the console.

15. What is SSL?

Ans: ssl is a protocol for providing encrypted data communications between two processes.

16. What is PMI? How to configure PMI?

Ans: monitoring and tuning–>PMI–>select any process (server1, nodeagent, dmgr) and then enable PMI–>then apply and then save. Select performance viewer–>current activity and then select enabled process and click the start monitoring button after that process select.

17. What is the UNIX command of all display server processes?

Ans: ps –ef| grep java

18. What is node?

Ans: logical group of servers.

19. How to start the server?

Ans: startserver.sh server1

20. How you get nodeagent……what you have to install to get nodeagent?

Ans: Custom Profile

21. How to add the node?

Ans: addnode.sh 8879

22. What is the application server?

Ans: The application server provides a runtime environment in which to deploy, manage, and run j2ee applications.

23. What is the node?

Ans: A node corresponds to a physical computer system with a distinct IP host address.The node name is usually the same as the host name for the computer.

24. What is the node?

Ans: A node corresponds to a physical computer system with a distinct IP host address. The node name is usually the same as the host name for the computer.

25. How many types of profiles are in nd product?

Ans: 1.deployment manager profiles 2.application server profiles 3.custom profile

26. What is diffrence b/w dmgr and other profiles?

Ans: dmgr app custom

1.its used for administration 1.admin console is there 1.plain node purpose of remaining profiles 2.initially one app server there 2.empty node 2.it supports the distributed 3.work independently environment. 4. Put applications 3.it is not included app server 4.admin console is there 5.work independently 6.do not put applications

27. Diff b/w 5.0 and 6.0?

Ans: Web Sphere Studio 3.5, comes up with Visual Age for Java. WSAD 5.0 supports J2EE 1.3 java specifications. RAD 6.0 supports J2EE 1.4 and integrated with Eclipse 3.0, UML Visual Editor, Tomcat Jakarta, Ant scripting, EJB universal test client and SOA tools.

28. What is the difference between web server and application server?

Ans: Application Server: takes care of Security, Transaction, Multithreading, Resource pooling, load balancing, clustering, performance, highly availability, scalability, etc. Exposes business logic to client applications through various protocols, possibly including HTTP. Supports deployment of .war and .ear files Application server = web server + EJB container.

29. Diff b/w weblogic and websphere?

Ans: Both BEA Weblogic and IBM’s WebSphere provide J2EE based application servers which are competitors. WebSphere leverages more on connectivity issues with MQ and legacy systems with strong dominance in J2EE.

30. Some problem is there in web server, so this information which log file contain?

Ans: http.log, plugin.log

31. What is jdbc?

Ans: jdbc is a low level pure java api used to execute sql statements.

32. What is datasource?

Ans: A data source is associated with a jdbc provider that supplies the specific jdbc driver implementation class

33. What is diff b/w type4 and type2?

Ans: type4 type2

1. It is pure java oriented 1.it is not a pure java oriented driver 2.require client side software 2.no need any client software

34. Some application not accessing, so what is the problem? This information which log file contains?

Ans: systemout, systemerr

35. In type3 client software which machine you have install?

Ans: server side machine

36. two databases there (oracle and db2),so I want 3 datasources for oracle and 2 data sources for db2 so create 3 datasource names for oracle and 2datasourcename for db2 is possible or not?

Ans: possible

37. What is jndi?

Ans: we can register resources in the application server’s java naming and directory interface (jndi) namespace. Client applications can then obtain the references to these resource objects in their programs.

38. Why use the boostrap port number?

Ans: client applications use the bootstrap port to access websphere’s built-in object request broker (orb) to use enterprise java beans in applications installed on the application server. The java naming and directory interface service provider url used by the client application needs to reference the bootstrap port to obtain an initial context for looking up ejb’s it wants to use. (For communicate two servers)

39. What are the appserver components?

Ans: admin server, web container, ejb container,j2c service, naming server, messaging engine, security server.

40. LDAP port number?

Ans: 389 or 636

41. How to start the server?

Ans: startserver.sh server1

42. Packages of websphere?

Ans: express, base, network deployment

43. What is webcontainer?

Ans: The web container provides a runtime environment for servlets, jsp’s, javabeans, and static content.

44. How to find out free diskspace from command prompt?

Ans: du -sk (kb) du -sm (mb)

45. How to find out certain server configuration details like port no, server name, node name, pid?

Ans: through admin console.

46. Configure the plug-in through admin console is possible or not?

Ans: possible

47. Where to set the path?

Ans: environments–>websphere variables

48. How many types of installations?

59. Application installed but not working. What are troubleshooting steps?

Ans: see jvm & application are up, check plugin-cfg.xml file for the root context used by the web application if it does not exist generate plugin and restart web server.

50. Applications installed fine, also generated plugin, but application still not working, in this case which log to see?

Ans: plugin.log

51. Default admin port?

Ans: 9060, ssl 9043

52. Default bootstrap port?

Ans: 2809

53. How to hit application without hitting the web server?

Ans: webcontainer port on application server

54. In how many ways you can perform administration?

Ans: console,,,JMX

55. No of ways of doing deployments?

Ans: Admin console…..jython (jacl) scripts

56. What is CellDiscoveryAddress

Ans: Node uses this port to talk to DMGR

57. What is NodeDiscoveryAddress

Ans: DMGR uses this port to talk to node

58. How websphere discovers a change in JSP and compiles it?

Ans: There is an algorithm that websphere uses to find the timestamp of .jsp and .class files. It checks that timestamp of .class file is always later than its corresponding .jsp file.

59. What is classloader?

60. how do you specify a jar file to be used by the application, consider that you have many jar files in your system?

Ans: classloader

61. What is a managed node?

Ans: Node with NodeAgent

62. What is a managed webserver?

Ans: Remote webserver access through local (dmgr/cell)

WAS Important interview questions Part-1

1. What is websphere?

The moment you ask this question, the first question that comes to mind is WebSphere applicaiton server. In reality, WebSphere is the name of a product family. IBM has many more products under the brand name WebSphere. WebSphere Application Server , WebSphere MQ, WebSphere Message broker, WebSphere business modeler, WebSphere process Server, WebSphere business monitor, WebSphere integration developer, WebSphere partner gateway are some of the products under this brand name.

2. Whats is a profile in websphere Application Server?

When you install WebSphere application server, executable files and configurations files are seperated. This allows you install the product once and create multiple sets of configurations which uses the same underlying core executables of the websphere application server installation. These are the profiles in websphere application server. As you know, there are many types of profiles and you can create multiple profiles.

3. What does nodeagent do in websphere Application Server?

We will have one nodeagnet per one node. The node agent acts as an mediator between the Deployment manmager and the node.

4. What is Sync in websphere Application Server?

WebSphere application server stores all the configuration data in one central location knows as 'Master repository'. And every node/server will have the local configuration repository. The sycn process make sure that the configuration in both local and master repositories are same and in-sync. The sync is a one dimentional process means, it will sync the configurations only from Master repository ==> local repository.

5. What is websphere plug-in for web server and where do i need to install the plug-in?

It is common practise to have web and app servers on different machines. WebSphere provides a plug-in which enables web server to talk to application server, this is known as web server plug-in. Web server plug-in will have a configuration file named plugin-config.xml which will have referenes to all the servers, clusters, applications, virtual hosts of the websphere application server. You can generate this configuration file from administration console, servers -->web servers. Select a web server and click generate plugin configuration file and then propagate the plugin. This plug-in needs to be installed on the web server machine

6. I don't have WebSphere installed on my web server how do i add to the websphere administration console ?

If you like to add your web server to that WebSphere administration console, you can do that by creating a unmanaged node and then add from servers-->web servers

7. Do i need a web server if i have a websphere application server?

Web Server and WebSphere application server provide two different functionalities. WebSphere application server do has an inbuilt web server functionality but it is recomended to use a seperate web server for many reasons. Some of them are: 1. By seperating web and application server activities, your application serving environment is more secure. 2. Using the webserver you can loadbalance the requests between multiple application servers.

8. How do edit/modify the property/configuration files?

It is recomended to modify all the configurations using the administration console. When you need to make any configuration changes, you need do the apply changes and sync them. Any changes you do at local repository level are discarded upon the next restart of that server because the sync is always from DMGR to local repository and changes are not saved to master repository. For example, if you edit a configuration file of server1 and restart it... the changes are lost. When the server starts it syncs the configuration from master repository.

9. What happens if my DMGR is not running?

DMGR is the single point of failure in WebSphere network deployment model. Even if DMGR is down, rest of the server will contine to run and serve the applications. However, anychanges you make in this situation are not saved to master configuration repository.

10. I installed a new application, what do i need to do before i can access it from the web server URL?

When you install a new application or update an application, your web server need to be aware of the changes. Which means you need to update the web server plug-in configuration file. So after a successful installation of an application with mapping to web server, you need to regenerate the plug-in configuration file and propagate it to web server.

11. what is a connecting pool ?
a connection pool is a cache of database connections maintained so that the connections can be reused when future requests to the database are required. Connection pools are used to enhance the performance of executing commands on a database. In connection pooling, after a connection is created, it is placed in the pool and it is used over again so that a new connection does not have to be established. If all the connections are being used, a new connection is made and is added to the pool. Connection pooling also cuts down on the amount of time a user must wait to establish a connection to the database.

12. What is virtual host in websphere application server?
Virutal host is a configuration not a physical one.  A configuration that lets a single machine resemble multiple host machines. Each virtual host has a logical name and a list of one or more DNS host aliases by which it is known.  By deafult, we wull have a default_house and admin_host virtual hosts defined in websphere application server.

13. how do i connect my application to talk to a database?
To achive this , you need to create a JDBC provider and datasource. The JDBC provider object encapsulates the specific JDBC driver implementation class for access to the specific vendor database of your environment. The data source object supplies your application with connections for accessing the database. The best way to learn more about this task is, login to administration console -->guided activities --> connecting to a database.

14. How can i make sure that my servers are available while restarting a cluster?
Use the option ripplestart ... It first stops and then restarts each member of the cluster.

15. I've made some changes to my applicaiton's web.xml , how and where should i update this file?
You can do this from the administration console. Go to enterprise applications -->select your application and click update. on the next panel, you'll have option to update the entire application, a single module or even a single file or multiple files.
Select the single file option and specify the file's path you like to update . Specify a relative path to the file that starts from the root of the war/ear file. So it looks something like this : app1.war/WEB-INF/web.xml

16. How do i minimize the downtime while i'm updating the applications ?
Use rollout update option. This option sequentially updates an application on multiple cluster members across a cluster. After you update an application's files or configuration, click Rollout Update to install the application's updated files or configuration on all cluster members of a cluster on which the application is installed.
Rollout update will save the application configurations then stops the cluster members on a node then syncs the configuration and stat the clusters members on that node. Then it proceeds to the next node and does the same steps.

17. We are getting a 'class not found' and developers like to know, if that class is being loaded or not. how can i assist them troubleshoot the issue?
WebSphere administration console has an utility using which you can see what classes are loaded at what scope for an application. Go to Troubleshooting -->class loader viewer and select the module.

18. We have some issue with our application server and we tried killing it using kill-9 command, the process disappeared for few seconds but it is back again. We did not start the server but it started. What would be the reason?
Servers > Application Servers > server_name. Then, under Server Infrastructure, click Java and Process Management > Process Definition > process > Monitoring Policy. Here we have an option Automatic Restart, this Specifies whether the process should restart automatically if it fails. On distributed systems, the default is to restart the process automatically.

19. Is there a way i can start my server along with nodeagent ?
Servers > Application Servers > server_name. Then, under Server Infrastructure, click Java and Process Management > Process Definition > process > Monitoring Policy. Here we have an option Node Restart State which specifies the desired behavior of the servers after the node completely shuts down and restarts.
    STOPPED - node agent does not start the server.
    RUNNING - the node agent always starts the server.
    PREVIOUS - the node agent starts the server only if the server was running when the node agent 

WebSphere Portal Interview Questions

WebSphere Portal Interview Questions 

List of interview questions that i might ask someone for the job of WebSphere Portal Server Administrator. What is the difference between Application Server and Portal Server ? Application servers extend the ability of a Web server to handle Web application requests, and enables a server to generate a dynamic, customized response to a client request. A portal server extends the application server by providing a portlet container that can run portlets and to create portal a website that provides users with a single point of access to Web-based resources by aggregating those resources in one place. What are the steps involved in deploying themes and skins in a clustered production websphere portal environment ? Export the WebSphere wps.ear (Portal EAR) using wsadmin. Use EarExpander tool to expand the exported wps.ear file. Copy the updated themes and skins into ../themes/html, ../skins/html folder. Use EarExpander tool to collapse the EAR directory into an EAR file. Use wsadmin to update the wps.ear to complete the deployment of updated themes and skins. What changes needs to be done to view changes to your theme and skins JSPs without restarting the portal server ? You need to enable automatic JSP loading by setting reloadingEnable property to true in ibm-web-ext.xmi file of the wps.ear. What are the 3 different ways of installing a portlet application in WebSphere Portal ? Install a portlet using the portal administration page using Web Modules portlet. Install a portlet using xmlaccess tool. Pre-deploy a portlet as a standard EAR by installing the portlet WAR file in WAS console and then registering the portlet using xmlaccess. What is the purpose of XMLAccess configuration file Export.xml & ExportRelease.xml ? What is the difference ? & When will you use one over the other ? Export.xml exports the complete portal configuration and useful when transferring configurations between development installations. ExportRelease.xml exports the complete portal configuration from the release domain as required by the portal ReleaseBuilder tool and useful when tranaferring different release configurations between staging and production environments. List me the steps involved in building a release in WebSphere Portal ? If you have a completely new installation of the staging server and the production server: Install the staging server, then install the production server. Develop a release on the staging server. Build the release on the staging server. Empty portal contents on the production server by running the WPSconfig.sh|bat action-empty-portal task. Import that release onto the production server. Refer to Transferring a complete configuration for information. If you already have a production server without a staging system: Export the release of your production server. Install an empty staging server using one of the following two methods: Install the staging server with the flag -W emptyPortal.active=True. After installing and configuring the staging server, run the WPSconfig.sh|bat action-empty-portal task. Import the production release onto the staging server. Refer to Transferring a complete configuration for information. Develop and build a new release on the staging server. Export that new release from the staging server. Use ReleaseBuilder to generate the differential between the two releases. Import the differential onto the production server. What is the purpose of ReleaseBuilder tool in WebSphere Portal ? ReleaseBuilder enables management of release configurations independent of user configurations and used during staging of follow-on releases of WebSphere portals, configurations, and artifacts need to be moved between systems. What are the steps involved in editing WebSPhere Member Manager (wmm.xml) files on a federated node ? On the primary node of the WebSphere Portal cluster, check out the files using ./WPSconfig.sh check-out-wmm-cfg-files-from-dmgr task. Make any changes to the Member Manager files. The files can be edited in the portal_server_root/wmm directory on the WebSphere Portal node. When you have completed your changes, check the files back in using ./WPSconfig.sh check-in-wmm-cfg-files-to-dmgr. How to change the default portal URI /wps/portal after installation ? Set the property WpsContextRoot to the new URI and run ./WPSConfig.sh modify-servlet-path task. List different types of user registry supported by WebSphere Portal ? LDAP (includes LDAP with an optional database user registry). Database user registry. Custom User registry, (non-LDAP, non-database). What is LDAP realm support and why would I want to use it? A Realm allows you to group users from one or more LDAP trees of one user registry and expose them as a coherent user population to WebSphere Portal; this is also referred to as horizontal partitioning. Realms allow a flexible user management with various configuration options; for example, you can combine principals from one or more corporate LDAP tree. A realm must be mapped to a Virtual Portal to allow the realm's defined user population to login to the Virtual Portal. What is an Application group and why would I want to use it ? Application groups is a concept that allows you to define user groups within the database user registry with members (users or groups) contained in the LDAP user registry you configured. The benefit of application groups is that you can create Groups that are only used in WebSphere Portal particularly in scenarios where there is Read-only LDAP or special group setup specific to the portal. What are the two methods to install the empty staging WebSphere portal server ? Empty portal contents on the staging server by running the ./WPSconfig.sh action-empty-portal. Install portal with the ./install.sh -W emptyPortal.active="True" option. How do you stop portal traffic to the node being upgraded in 24x7 cluster upgrade process ? Locate the cluster member being upgraded, and change the value in the Configured weight column from a value to zero and make sure the plugin config information is propagated to webserver to stop traffic. How to set limits on searches for users and groups ? Setting a maximum number of search results maximumSearchResults="200" in wmm.xml What portal resources are scoped for virtual portal ? Portal pages. Portlet instances. Portal Search Engine search services and search collections. This includes the search content sources. What portal resources can't be seperated for virual portal ? Themes and skins. Vault segments and vault slots. Supported clients and markups. Composite applications and templates. Policies. How do you enable temporary and extended trace logging for WebSphere Portal ? Temporary traces can be set for a temporary period by using the administration portlet Enable Tracing or the IBM WebSphere Application Server administrative console and also using the Enable Tracing portlet in the portal administration page. To enable extended trace settings for a longer period of time, that is, for more than one session, switch them on in the WebSphere Application Server configuration, save the updates and restart the portal server. What are the different states of the syndication process ? Idle: No syndication is occurring. Pending: A request has been made to the syndicator, but it has yet to initiate a request to the syndication application. Queued: The syndicator has sent a request to the syndication application, but syndication is not yet active. Active: Syndication is occurring between the syndicator and subscriber. Disabled: Syndication is currently disabled. What are the two types of rendering portlets ? Local rendering portlet and Remote rendering portlet You can also find answers to all of the questions in the WebSphere Portal 6.0 Information Center or check theWebSphere Portal Books  Source Link :  http://webspherehelp.blogspot.com

Monitoring

Monitoring overall system health

Monitoring overall system health is fundamentally important to understanding the health of every system involved with your system. This includes Web servers, application servers, databases, back-end systems, and any other systems critical to running your Web site.

Before you begin

If any system has a problem, it might cause the servlet is slow message to appear.. WebSphere Application Server provides Performance Monitoring Infrastructure (PMI) data to help monitor the overall health of the WebSphere Application Server environment. PMI provides average statistics on WebSphere Application Server resources, application resources, and system metrics. Many statistics are available in WebSphere Application Server, and you might want to understand the ones that most directly measure your site's resources to detect problems.

About this task

Table 1. Monitoring overall system health. To monitor overall system health, monitor the following statistics at a minimum:

Metric	Meaning
Average response time	Include statistics, for example, servlet or enterprise beans response time. Response time statistics indicate how much time is spent in various parts of WebSphere Application Server and might quickly indicate where the problem is (for example, the servlet or the enterprise beans).
Number of requests (transactions)	Enables you to look at how much traffic is processed by WebSphere Application Server, helping you to determine the capacity that you have to manage. As the number of transactions increase, the response time of your system might be increasing, showing the need for more system resources or the need to retune your system to handle increased traffic.
Number of live HTTP sessions	The number of live HTTP sessions reflects the concurrent usage of your site. The more concurrent live sessions, the more memory is required. As the number of live sessions increase, you might adjust the session time-out values or the Java virtual machine (JVM) heap available.
Web server thread pools	Interpret the Web server thread pools, the Web container thread pools, and the Object Request Broker (ORB) thread pools, and the data source or connection pool size together. These thread pools might constrain performance due to their size. The thread pools setting can be too small or too large, therefore causing performance problems. Setting the thread pools too large impacts the amount of memory that is needed on a system or might cause too much work to flow downstream if downstream resources cannot handle a high influx of work. Setting thread pools too small might also cause bottlenecks if the downstream resource can handle an increase in workload.
The Web and Enterprise JavaBeans (EJB) thread pools
Database and connection pool size
Java virtual memory (JVM)	Use the JVM metric to understand the JVM heap dynamics, including the frequency of garbage collection. This data can assist in setting the optimal heap size. In addition, use the metric to identify potential memory leaks.
CPU	You must observe these system resources to ensure that you have enough system resources, for example, CPU, I/O, and paging, to handle the workload capacity.
I/O
System paging

Enable Performance Monitoring Infrastructure (PMI)

1. Procedure

   1. Open the administrative console.
   2. Click Servers > Application Servers in the console navigation tree.
   3. Click a server.
   4. Click the Configuration tab.
   5. Click Performance Monitoring Infrastructure (PMI) under Performance.
   6. Select the  check box.
   7. Optionally, select the check box Use sequential counter updates to enable precise statistic update.
   8. Optionally, choose a statistic set that needs to be monitored under Currently Monitored Statistic Set.
   9. Optionally, click on Custom to selectively enable or disable statistics. Choose a component from the left side tree and enable or disable statistics on the right side table. Go back to the main PMI configuration page by clicking the Performance Monitoring Infrastructure link.
   10. Click Apply or OK.
   11. Click Save.
   12. Restart the application server. The changes you make will not take effect until you restart the application server.

   
   

   When in the Configuration tab, settings apply after the server is restarted.
   
   
   

   

   Statistic set	Description
   None	All statistics are disabled.
   Basic	Statistics specified in J2EE 1.4, as well as top statistics like CPU usage and live HTTP sessions are enabled. This set is enabled out-of-the-box and provides basic performance data about runtime and application components.
   Extended	Basic set plus key statistics from various WebSphere® Application Server components like WLM, and dynamic caching are enabled. This set provides detailed performance data about various runtime and application components.
   All	All statistics are enabled.
   Custom	Enable or disable statistics selectively.

   
   Monitoring through Tivoli
   
   
   To monitor several of these statistics, WebSphere Application Server provides the Performance Monitoring Infrastructure to obtain the data, and provides the Tivoli^® Performance Viewer (TPV) in the administrative console to view this data.
   To monitor several of these statistics, WebSphere Application Server provides the Performance Monitoring Infrastructure to obtain the data, and provides the Tivoli Performance Viewer (TPV) and the optional IBM Tivoli Composite Application Manager for WebSphere Application Server in the administrative console to view this data.

Procedure

• Create logs.
  1. Click Monitoring and Tuning > Performance Viewer > Current Activity > server_name > Settings > Log in the console navigation tree. To see the Log link on the Tivoli Performance Viewer page, expand the Settings node of the TPV navigation tree on the left side of the page. After clicking Log, the TPV log settings are displayed on the right side of the page.
  2. Click on Start Logging when viewing summary reports or performance modules.
  3. When finished, click Stop Logging . Once started, logging stops when the logging duration expires, Stop Logging is clicked, or the file size and number limits are reached. To adjust the settings, see step 1.
  By default, the log files are stored in the profile_root/logs/tpv directory on the node on which the server is running. TPV automatically compresses the log file when it finishes writing to it to conserve space. At this point, there must only be a single log file in each .zip file and it must have the same name as the .zip file.
• View logs.
  1. Click Monitoring and Tuning > Performance Viewer > View Logs in the console navigation tree.
  2. Select a log file to view using either of the following options:

     Explicit Path to Log File

     Choose a log file from the machine on which the browser is currently running. Use this option if you have created a log file and transferred it to your system. Click Browse to open a file browser on the local machine and select the log file to upload.

     Server File

     Specify the path of a log file on the server.In a stand-alone application server environment, type in the path to the log file. Theprofile_root\logs\tpv directory is the default on a Windows system.

  3. Click View Log. The log is displayed with log control buttons at the top of the view.
  4. Adjust the log view as needed. Buttons available for log view adjustment are described below. By default, the data replays at the Refresh Rate specified in the user settings. You can choose one of the Fast Forward modes to play data at rate faster than the refresh rate.

     Rewind	Returns to the beginning of the log file.
     Stop	Stops the log at its current location.
     Play	Begins playing the log from its current location.
     Fast Forward	Loads the next data point every three (3) seconds.
     Fast Forward 2	Loads ten data points every three (3) seconds.

  You can view multiple logs at a time. After a log has been loaded, return to the View Logs panel to see a list of available logs. At this point, you can load another log.TPV automatically compresses the log file when finishes writing it. The log does not need to be decompressed before viewing it, though TPV can view logs that have been decompressed.

For More:http://websphereapplicationservernotes.files.wordpress.com/2012/04/websphere-doctor-6-using-tpv.pdf

JDBC Driver Types

JDBC drivers are divided into four types or levels. The different types of jdbc drivers are:

Type 1: JDBC-ODBC Bridge driver (Bridge)
Type 2: Native-API/partly Java driver (Native)
Type 3: AllJava/Net-protocol driver (Middleware)
Type 4: All Java/Native-protocol driver (Pure)

4 types of jdbc drivers are elaborated in detail as shown below:

Type 1 JDBC Driver

JDBC-ODBC Bridge driver

The Type 1 driver translates all JDBC calls into ODBC calls and sends them to the ODBC driver. ODBC is a generic API. The JDBC-ODBC Bridge driver is recommended only for experimental use or when no other alternative is available.

Type 1: JDBC-ODBC Bridge

Advantage

The JDBC-ODBC Bridge allows access to almost any database, since the database's ODBC drivers are already available.

Disadvantages

1. Since the Bridge driver is not written fully in Java, Type 1 drivers are not portable.
2. A performance issue is seen as a JDBC call goes through the bridge to the ODBC driver, then to the database, and this applies even in the reverse process. They are the slowest of all driver types.
3. The client system requires the ODBC Installation to use the driver.
4. Not good for the Web.

Type 2 JDBC Driver

Native-API/partly Java driver

The distinctive characteristic of type 2 jdbc drivers are that Type 2 drivers convert JDBC calls into database-specific calls i.e. this driver is specific to a particular database. Some distinctive characteristic of type 2 jdbc drivers are shown below. Example: Oracle will have oracle native api.

Type 2: Native api/ Partly Java Driver

Advantage

The distinctive characteristic of type 2 jdbc drivers are that they are typically offer better performance than the JDBC-ODBC Bridge as the layers of communication (tiers) are less than that of Type
1 and also it uses Native api which is Database specific.

Disadvantage

1. Native API must be installed in the Client System and hence type 2 drivers cannot be used for the Internet.
2. Like Type 1 drivers, it’s not written in Java Language which forms a portability issue.
3. If we change the Database we have to change the native api as it is specific to a database
4. Mostly obsolete now
5. Usually not thread safe.

Type 3 JDBC Driver

All Java/Net-protocol driver

Type 3 database requests are passed through the network to the middle-tier server. The middle-tier then translates the request to the database. If the middle-tier server can in turn use Type1, Type 2 or Type 4 drivers.

Type 3: All Java/ Net-Protocol Driver

Advantage

1. This driver is server-based, so there is no need for any vendor database library to be present on client machines.
2. This driver is fully written in Java and hence Portable. It is suitable for the web.
3. There are many opportunities to optimize portability, performance, and scalability.
4. The net protocol can be designed to make the client JDBC driver very small and fast to load.
5. The type 3 driver typically provides support for features such as caching (connections, query results, and so on), load balancing, and advanced
system administration such as logging and auditing.
6. This driver is very flexible allows access to multiple databases using one driver.
7. They are the most efficient amongst all driver types.

Disadvantage

It requires another server application to install and maintain. Traversing the recordset may take longer, since the data comes through the backend server.

Type 4 JDBC Driver

Native-protocol/all-Java driver

The Type 4 uses java networking libraries to communicate directly with the database server.

Type 4: Native-protocol/all-Java driver

Advantage

1. The major benefit of using a type 4 jdbc drivers are that they are completely written in Java to achieve platform independence and eliminate deployment administration issues. It is most suitable for the web.
2. Number of translation layers is very less i.e. type 4 JDBC drivers don't have to translate database requests to ODBC or a native connectivity interface or to pass the request on to another server, performance is typically quite good.
3. You don’t need to install special software on the client or server. Further, these drivers can be downloaded dynamically.

Disadvantage

With type 4 drivers, the user needs a different driver for each database.