Datasource configuration in JBoss?

A Datasource is a Java Naming and Directory Interface (JNDI) object used to obtain a connection from a connection pool to a database. In order to create a DataSource (so that you can use JDBC connectivity) you need to create a file ending with -ds.xml under the "deploy" directory of your server.

The default Datasource file

The default data source configured with JBoss 4.0 is the HypersonicDB data source.
Here's the hsqldb-ds.xml that is shipped with jboss :

<?xml version="1.0" encoding="UTF-8"?>

<datasources>
    <local-tx-datasource>

        <jndi-name>DefaultDS</jndi-name>

        <connection-url>jdbc:hsqldb:${jboss.server.data.dir}${/}hypersonic${/}localDB
        </connection-url>

        <driver-class>org.hsqldb.jdbcDriver</driver-class>

        <user-name>sa</user-name>
        <password></password>

        <min-pool-size>5</min-pool-size>
        <max-pool-size>20</max-pool-size>

        <idle-timeout-minutes>0</idle-timeout-minutes>

        <track-statements />

        <security-domain>HsqlDbRealm</security-domain>

        <prepared-statement-cache-size>32</prepared-statement-cache-size>

        <metadata>
            <type-mapping>Hypersonic SQL</type-mapping>
        </metadata>

        <depends>jboss:service=Hypersonic,database=localDB</depends>

    </local-tx-datasource>

    <mbean code="org.jboss.jdbc.HypersonicDatabase" name="jboss:service=Hypersonic,database=localDB">
        <attribute name="Database">localDB</attribute>
        <attribute name="InProcessMode">true</attribute>
    </mbean>

</datasources>

As you can see from this file, JDBC connectivity uses Connection pools to dispatch Connections. The initial size and the max size of the Connection pool can be configured with <min-pool-size> and <max-pool-size>.

With <idle-timeout-minutes> you can indicate the maximum time a connection may be idle before being closed and returned to the pool. If not specified it's 15 minutes.

<track-statements/> is a debugging feature: it checks that all statements are closed when the connection is returned to the pool: remember to disable it in production environment.

 <security-domain> tells to use the security domain defined in conf/login-config.xml : in our case:

<application-policy name="HsqlDbRealm">
    <authentication>
        <login-module
            code="org.jboss.resource.security.ConfiguredIdentityLoginModule"
            flag="required">
            <module-option name="principal">sa</module-option>
            <module-option name="userName">sa</module-option>
            <module-option name="password"></module-option>
            <module-option name="managedConnectionFactoryName">jboss.jca:service=LocalTxCM,name=DefaultDS
            </module-option>
        </login-module>
    </authentication>
</application-policy>

<prepared-statement-cache-size> is the number of prepared statements per connection to be kept open and reused in subsequent requests. They are stored in a LRU cache. The default is 0 (zero), meaning no cache.

Enterprise datasources

I) Local Datasource

This is a sample Oracle local datasource configuration: a local DataSource is one that does not support two phase commit using a java.sql.Driver.

<datasources>
    <local-tx-datasource>
        <jndi-name>OracleDS</jndi-name>
        <connection-url>jdbc:oracle:thin:@youroraclehost:1521:yoursid</connection-url>

        <driver-class>oracle.jdbc.driver.OracleDriver</driver-class>
        <user-name>x</user-name>
        <password>y</password>

        <min-pool-size>5</min-pool-size>
        <max-pool-size>100</max-pool-size>
        <query-timeout>60</query-timeout>
        <exception-sorter-class-name>org.jboss.resource.adapter.jdbc.vendor.OracleExceptionSorter
        </exception-sorter-class-name>

        <metadata>
            <type-mapping>Oracle9i</type-mapping>
        </metadata>
    </local-tx-datasource>

</datasources>




Notice the <query-timeout> tag which configures the maximum of seconds before a query times out ( avaliable since Jboss 4.0.3). The <exception-sorter-class-name> is used to Check the Oracle error codes and messages for fatal errors.

Remember: In order to use an Oracle datasource you need to put the jdbc driver in jBoss's server's lib directory.

II) XA Datasource

This is a sample XA Datasource: XA DataSources support two phase commit using a  javax.sql.XADataSource

<datasources>
    <xa-datasource>
        <jndi-name>XAOracleDS</jndi-name>
        <track-connection-by-tx></track-connection-by-tx>
        <isSameRM-override-value>false</isSameRM-override-value>
        <xa-datasource-class>oracle.jdbc.xa.client.OracleXADataSource
        </xa-datasource-class>
        <xa-datasource-property name="URL">jdbc:oracle:oci8:@tc
        </xa-datasource-property>
        <xa-datasource-property name="User">scott
        </xa-datasource-property>
        <xa-datasource-property name="Password">tiger
        </xa-datasource-property>

        <exception-sorter-class-name>org.jboss.resource.adapter.jdbc.vendor.OracleExceptionSorter
        </exception-sorter-class-name>

        <no-tx-separate-pools></no-tx-separate-pools>


        <metadata>
            <type-mapping>Oracle9i</type-mapping>
        </metadata>
    </xa-datasource>

    <mbean
        code="org.jboss.resource.adapter.jdbc.vendor.OracleXAExceptionFormatter"
        name="jboss.jca:service=OracleXAExceptionFormatter">
        <depends optional-attribute-name="TransactionManagerService">jboss:service=TransactionManager
        </depends>
    </mbean>

</datasources>

Notice the <isSameRM-override-value>  set to false to fix problems with Oracle. The element <track-connection-by-tx/>  can be omitted on JBoss 5 where it's enabled by default.
At last, the  <no-tx-separate-pools> means that Oracles XA datasource cannot reuse a connection outside a transaction once enlisted in a global transaction and vice-versa.

How to configuration maxThreads for Tomcat ?

Tomcat maxThreads represents the maximum number of request
processing threads to be created by the HTTPConnector.

<Connector port="8080" address="localhost"     
     maxThreads="250" maxHttpHeaderSize="8192"
     emptySessionPath="true" protocol="HTTP/1.1"
     enableLookups="false" redirectPort="8443" acceptCount="100"
     connectionTimeout="20000" disableUploadTimeout="true" />

This determines the maximum number of simultaneous requests that can be handled. If not specified, this attribute is set to the default value of 200.

How the process works:

• At server startup, the HTTP Connector will create a number of processing threads based on the value configured for the minSpareThreads attribute.
• Each incoming request requires a thread for the duration of that request.
• If the number of simultaneous requests cannot be handled by the currently available request processing threads, additional threads will be created up to the configured maximum (the value of the maxThreads attribute).
• If still more simultaneous requests are received, they are stacked up up to the configured maximum (the value of the acceptCount attribute).
• Any further simultaneous requests will receive "connection refused" errors, until resources are available to process them.

Guidelines for maxThreads:
maxThreads is an important tuning parameter, however if you are reaching an error like:

org.apache.tomcat.util.threads.ThreadPool logFull SEVERE: All threads (150) are
currently busy, waiting. Increase maxThreads (150) or check the servlet status

you should at first investigate if it's rather a problem of individual requests taking too long: are your threads returning to the pool? if, for example, database connections are not released, threads pile up waiting to obtain a database connection thereby making it impossible to process additional requests. This is a problem in your webapp.
Take a thread dump to find out where they're stuck. Increasing too much maxThreads will lead to :

• Consume a good chunk of memory.
• Your system will spend too much time context switching

So once you have already optimized your application try raising you maxThread attribute up to 500-750. I wouldn't advice to create larger Connectors, rather if 750 Connections are not enough create a Cluster configuration with several Tomcat instances. For example 2 instances of tomcat each one with maxThreads=500 instead of a single Tomcat with maxThreads=1000

Relation between Hits Per sec, CPU Usage & Response times in LoadRunner?

As the hits per second increases....

Response times:-
1. If the application is good enough to high user load, we dont see any changes in teh response times with respect to hits per sec
2. If the application is not good enough & with performance bottlenecks then response times gradually increase with increase in hits per sec.
3. Finally if there is any network delay which occurs intemittently in some instances will increase the response times of all the transaction at that moment & hence due to which hits per sec & throughput decreases.

what is Wasted Time in LoadRunner ?

Wasted time is time spent on activities whose purpose is to support test analysis, but would never be performed by a browser user, for example, time spent keeping transaction statistics for later reporting. Wasted time is calculated internally by LoadRunner. Your script can also add wasted time with lr_wasted_time.


Sometimes, you may enter activities in a script that your do not want reported as part of the transaction statistics. Generally, these are activities related to record keeping, logging, or custom analysis. If you enhance the script with steps whose durations should not be included in the test statistics, you can track the time used by these steps with lr_start_timer and lr_end_timer. Then, the function lr_wasted_time is used for adding this user-determined time to the internally generated wasted time.


You can retrieve the total wasted time (both that generated by LoadRunner automatically and that added with lr_wasted_time) with the function lr_get_transaction_wasted_time, or with lr_get_trans_instance_wasted_time, as appropriate.

When VuGen creates the log file, output.txt, and when on line testing generates the Vuser log files, no action is taken with the wasted time. The actual elapsed transaction times are reported. The lr_get_transaction_duration function also returns the actual elapsed transaction time. This information may be useful in analyzing and developing test scripts.


However, in the on-line graphs in the LoadRunner Controller and the transaction response time graphs in the LoadRunner Analysis, the transaction times are reported after subtracting the wasted time. This is the time most pertinent to understanding the system being tested.

What are the HP LoadRunner 11.0 Features

HP LoadRunner for the Windows operating system Software version: 11.00
Publication date: October 2010
What's New
Protocols
Ajax TruClient - An advanced protocol for modern JavaScript based applications (including Ajax) emulating user activity within a web browser. Scripts are developed interactively in Mozilla Firefox.
Silverlight - A new protocol for Silverlight based applications emulating user activity at the transport level. Allows generating high level scripts by automatically importing and configuring WSDL files used by the application.
Java over HTTP - A new protocol designed to record java-based applications and applets. It produces a Java language script using web functions. This protocol is distinguished from other Java protocols in that it can record and replay Java remote calls over HTTP.
Citrix
The Citrix Protocol now supports Citrix Online Plugin versions 11.2 and 12.0.
Added support for Citrix XenApp Server 5.0
Oracle NCA - NCA Java object property support now provides automated creation and registration within a script of a query-answer table of communication between client-side Java objects and the Oracle NCA server.
SAPGUI - Added support for SAPGUI for Windows Client version 7.20..
Service Test - The LoadRunner Controller can run scripts created in HP Service Test 11.00, HP's solution for creating and running automated tests for SOA and headless technologies. Refer to the Service Test documentation for details of creating Service Test scripts for a load testing scenario.

FeaturesData Format Extension (DFE) - Enhanced data format capabilities for the Web (HTTP/HTML) protocol family. Allows converting raw HTTP traffic into a maintainable and structured XML format and enables correlations by XPATH.
Correlation Studio - Web (HTTP/HTML) automatic correlation mechanism has been enhanced to search for possible correlations in the larger scope of snapshot data created during code generation including data formatted by DFE.
Snapshot View - New snapshot view for Web (HTTP/HTML) protocol steps allows viewing complete HTTP traffic in both raw and DFE generated formats.
VuGen - HP ALM Integration - Enhanced integration with HP Application Lifecycle Management platform that serves also Quality Center and Performance Center editions..
Windows Support - Added support for Windows 7 and Windows Server 2008. See below for limitations. Analysis Reports - Enhanced Analysis reports are more customizable. Analysis data can be exported to a variety of formats, including Word, Excel, PDF, and HTML. New report templates allow saving report definitions and generating reports based on a template.

LIMITATIONS:-
VuGen
SAP (Click and Script) recording. During recording, if you use a keyboard option instead of a UI element (for example, pressing Enter instead of clicking the log on button), the step may not be recorded. In general, when recording your script, it is recommended to use UI elements rather than keyboard options.
Citrix snapshots. Black snapshots may appear during record or replay when using Citrix Presentation Server 4.0 and 4.5 (before Rollup Pack 3).
Possible workaround: On the Citrix server select Start Menu > Settings > Control Panel > Administrative Tools > Terminal Services Configuration > Server Settings > Licensing and change the setting Per User or Per Device to the alternative setting (ie If it is set to Per User , change it to Per Device and vice versa.)

Recording Window Size and XenApp Plugin for Hosted Applications 11. The recording window size options does not work properly with the XenApp Plugin for Hosted Applications 11. The size of the client window is installed, but the server screen resolution is not. This is a Citrix Client bug and will be fixed in future Citrix Client versions.

Workaround: When recording, set the window size equal to the local screen resolution. When replaying/load testing, set the VuGen or Load Generator's screen resolution to equal the resolution used when the script was recorded.
-->For the following protocols, replay is supported but recording is no longer supported: Siebel DB2, Siebel MSSQL, Siebel Oracle, and Voice XML.
-->In Test Result reports , you can only use the Export to HTML file utility for scripts replayed in version 9.50 and later. To generate an HTML report for scripts created with earlier versions, run the script again in the 9.50 version (or later) of the product.
-->If you terminated the Protocol Advisor immediately after the detection process started, the Protocol Advisor may leave a zombie process of the detected application, causing all recordings and detection sessions that follow to fail. Workaround: Manually terminate the zombie process.
-->The new Web snapshot model is backward compatible with previous versions of LoadRunner, however some snapshot data may be missing. If this occurs, regenerate the script.
-->The JSON Data Format Extension does not work in UNIX environments.
-->Recording a network based application on Windows 7. To record a network-based application (including Web), IPv6 communication must be disabled. Follow the instructions in http://www.addictivetips.com/windows-tips/how-to-disable-ipv6-in-windows-7/ to disable IPv6 in Windows 7.
-->For protocols using XML, replay fails to create a request when a parameterized input argument contains the ampersand (&) character.

Correlation Studio
In VuGen, when correlating large amount of snapshot data, in some cases the parameter is not created and data is not correlated.
Scan for correlation will work on a script that was regenerated and replayed with the early access version.

When an application server should be used?

You should consider an application server when you have a need for:

• Integration with existing systems and databases
• Website support

Secondary reasons to use application servers derive from the primary reasons. A few secondary reasons are:

• E-Commerce
• Web-integrated collaboration
• Component re-use

One way to look at application servers is that they are a formalization of a solution to a problem that has been around for a long time. That problem can characterized as a need to create an integrated presentation and processing environment for existing systems and databases. The presentation has pretty much been decided with browsers now being the dominant interface. This is why you usually see a Web server paired with or included in an application server. The integrated processing has been moving towards components for some time. Application servers provide containers for such components along with application program interfaces (APIs) to support the components. These APIs are to the existing systems and databases.

Application server definition ?

An application server is a component-based product that resides in the middle-tier of a server centric architecture. It provides middleware services for security and state maintenance, along with data access and persistence.
Java application servers are based on the Java™ 2 Platform, Enterprise Edition (J2EE™). J2EE uses a multi-tier distributed model. This model generally includes a Client Tier, a Middle Tier, and an EIS Tier. The Client Tier can be one or more applications or browsers. The J2EE Platform is in the Middle Tier and consists of a Web Server and an EJB Server. (These servers are also called "containers.") There can be additional sub-tiers in the middle tier. The Enterprise Information System (EIS) tier has the existing applications, files, and databases.
For the storage of business data, the J2EE platform requires a database that is accessible through the JDBC, SQLJ, or JDO API. The database may be accessible from web components, enterprise beans, and application client components. The database need not be accessible from applets.
See the related content links below for more information.