IBM WebSphere Application Server (IBM) database connection pool Analyzer

A tool that analyzes problems in JDBC on WebSphere Application Server connection pools.

Posting date: June 6, 2008

Updated: 8 October 2010
Version 2.3 supports transactions analysis

This tool uses a heuristic analysis engine to help you resolve issues related to the pools of JDBC (Java ™ Database Connectivity) connections and to find leaks of JDBC connection.

JDBC driver is used by applications written in Java to define how a client accesses the database resources. JDBC connection pooling can improve time response for a given application, requiring connections, including Web-based applications. For example, when a user makes a request to a resource on the Web, the resource accesses a data source. Total data store overload rises quickly when it is used in applications on the Web, resulting in a deterioration in performance. However, when using connection pooling features Web applications are less affected. Performance improvements of up to 20 times can be made.

With connection pooling, most user applications will undertake no overhead of creating a new connection because the data source can locate and use an existing connection in the connection pool. When the request is satisfied, and the response is returned to the user resource returns the connection pool connection for reuse. Cut overheads are avoided. Each user request commits a fraction of the cost of the connection or disconnection. After the initial resources are used to produce the additional pool connections is negligible because existing connections are reused.

For example, if a JDBC connection pool is deployed incorrectly and JDBC connections are not released after use, applications can suffer crashes, deprivation of resources and other connectivity problems. IBM WebSphere ® Application Server database connection pool Analyzer allows you to analyze the JDBC connection pool leaks and resolve JDBC pool connection problems especially when you use WebSphere Application Server.

The tool analyzes traces of JDBC connection pool manager and provides the following features:

The tool performs the following:

Jinwoo Hwang is a software engineer, team leader and a technical team of technical support for WebSphere Application Server, which is based in Research Triangle Park, N.C. leader He joined IBM in 1995 and has worked with IBM Global Services learning, IBM Consulting Services and development prior to his current position. Mr. Hwang is an IBM Certified Solution Developer as well as a SUN Certified Programmer for the Java 2 platform. He is the architect and developer of the following tools:

Mr. Hwang is also the author of C programming for novices (Yonam Press, 1995), as well as numerous articles technology aggregated on his personal website: http://jinwoohwang.sys-con.com/.

Trade-marks

SQL Server Express and VS2010 Web Application .mdf errors (Weblogs @ ASP.NET) file

I have installed SQL Server 2008 and SQL Server 2008 Express on my new Windows 7 development environment with Visual Studio 2010. I could obtain SQL Server 2008 to work correctly, but I could not express .mdf database for the sample web application projects without receiving the error below:

Unable to generate an instance of SQL Server user due to a failure in starting the process for the user instance. The connection will be closed.

For example, I was creating an ASP.NET Web application. When I ran the application and attempt to register a new user, I received an error:

 

I muddled by many daunting trials I wore it while I tried to determine if the problem was due to the "patch incompatibility" necessary with SQL Server 2008 and Windows 7, or if it was due to SQL Server Express is installed correctly, or VS2010 arrrgggh! Needless to say that many of reinstalls many products made prior to the conclusion of the forum post below (and the fix was simple!):

http://forums.ASP.NET/t/1377174.aspx

Unable to generate an instance of SQL Server user due to a failure in starting the process for the user instance. The connection will be closed.

The highest position proposed delete directory SQLEXPRESS and rebooting, I did. It should be noted, my path was quite different from that recommended in the above post. I used the file manager to find "SQLEXPRESS".

C:\Users\Nannette\AppData\Local\Microsoft\Microsoft SQL Server Data\SQLEXPRESS

After reboot, I received another error: the specific instance or network error has occurred in establishing a connection to SQL Server. The server is not found or was not available. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Shared Memory provider, error: 40 - could not open a connection to SQL Server) One of the above post readers suggested patch below:

Go to: Control Panel--> > Services administrative tools

right-click the service SQL Server (SQLEXPRESS) then Properties-> Then GoTo Logon tab-> select the local system account option-> apply-> OK

Note in my Windows 7 install administration tools displayed in the Control Panel, so I had to find "Admin" from the Panel to the Administrative Tools icon. When I arrived, my local system account was already setup, what was not my problem.

However, by taking these steps I found the SQL Server Express has been set to automatic but has not started. This is why I started it.

I then returned to my web application and I was able to open the file ASPNETDB.MDF in my VS2010 environment, and I was able to run the application and register a new user! No more errors! Can be of your dreams in ASP.NET! Nannette Thacker

Using application HTML5 cache to create offline Web Applications (java .sys - con .com)

HTML5 brought the application, a new feature that allows to make web applications and sites available offline cache. The new standard also provides a simple way to preload some or all of your web application assets (HTML files, images, CSS, JavaScript and so on) while the client is always online. In this process of caching files are stored in a cache for the application, where they sit ready for further offline use.

Compare this to regular browser, in which the pages that you visit are cached in the cache of the browser based on the rules of server and configuring client-side caching. But even if web pages are cached normally, it does not provide a reliable way to allow you to access the pages while you are offline (by plane, for example). In addition, an application cache can cache pages that have not been visited and are generally not available in the regular browser cache. Preloading files can even speed up the performance of your site, if you use course bandwidth to download these files at the outset.

Regularly caching can lead to undesirable results while you're offline.
The mechanism that makes available web applications offline is simple: create a manifest file lists the assets of your application and the reference in an attribute manifest in html elements (text) of your web pages. Simple sounds? This is the case. Don't forget that there are some common misconceptions about how offline web apps work and any caching of the browser are now for you, you can get a few surprises (tricky) when you try to debug and test your web applications (online and offline). This article explains what it takes to fend for themselves, so you don't have to learn the hard way. This article also covers some lower-level object and event features that you can tap application cache. Sounds good? Say great start!

Note: a startup files that comprise a web application offline sample set is available at: http://tech.kaazing.com/training/offline/peter-lubbers-html5-offline-web-apps-presentation-code.zip

Fundamental principles
Let's start with the basics. Consider a web application that has a few web pages: a page index, a CSS file, images and JavaScript files. This web site may be made available offline in less than five minutes (once you get it blocking). Here's how:

Open your favorite text editor, create a text file and save it with the extension .manifest. For example, offline.manifest.
Add the following directive in the first line:
CACHE MANIFEST
List the files that you want to make available offline (one row per file), as shown in the following example:

CACHE MANIFEST
index.html
cache.html
Resources/IMG/HTML5.PNG
Resources/CSS/html5.css
Resources/js/HTML5.js

Note: files must be referenced in the manifest file. Full URL is allowed as well.

Open files HTML that you want to make available offline (index.html and cache.html in this case) and add the manifest attribute to the html elements as follows:

Configure your server to be used with the correct mime type .manifest files (this is covered more in detail later) will to index your site. The page load, and to store the files locally, most browsers will ask if you want to make the files available for use in offline mode. The browser will then be analyzed the manifest file and download all of the assets specified in the file. Note: Unlike implementing caching regular browser, you haven't actually visit each page to load in the cache.Go application offline and continue to browse and enjoy your site.

Notification of storage offline browser

Peter Lubbers is documentation and training Kaazing Director where he oversees all aspects of documentation and training. He is co-author of the book Apress Pro HTML5 programming and taught HTML5 training courses. A follower of the HTML5 and WebSocket, Peter often speaks at international events.

Prior to joining Kaazing, Peter worked as an architect information at Oracle, where he wrote many books. It also develops solutions for automation documentation and two of his inventions are patented.

Originally from the Netherlands, Peter served a special forces commando in the Royal Dutch Green Berets. In his time free (ha!) Peter likes to run ultra-marathons. He is the 2007 and 2009 ultrarunner.net Series champion and three times winner of the Tahoe Super Triple marathon. Peter lives in the Tahoe national forest and likes to operate in the foothills of the Sierra Nevada of Lake Tahoe (preferably in only once!).