http://wldj.sys-con.com/ Latest articles from Peter Holditch Copyright 2008 WEBLOGIC JOURNAL Fri, 25 Jul 2008 13:34:00 GMT WEBLOGIC JOURNAL 10 http://backend.userland.com/rss http://wldj.sys-con.com/read/185295.htmhttp://wldj.sys-con.com/read/185295.htm Sat, 18 Feb 2006 10:30:00 GMT In this column over the years, I have spent a considerable amount of time talking about contention and locking in the database tier. At the end of the day, the endless conversations about scaling the application tier boil down to less than a bag of beans if a scaled application can't go any faster because the database has hit a limit. http://wldj.sys-con.com/read/169376.htmhttp://wldj.sys-con.com/read/169376.htm Thu, 26 Jan 2006 18:45:00 GMT I have been knocking around the computer industry for a while now, and I've noticed some changes in my contemporaries and myself... For one thing, the buttons around the stomach of those old shirts that have eluded capture by my wife are looking a bit more strained than they did in the shirts' heyday. http://wldj.sys-con.com/read/138276.htmhttp://wldj.sys-con.com/read/138276.htm Sat, 29 Oct 2005 12:15:00 GMT 'High performance' is what everybody strives for when putting together a new system. Technical folk often spend hours hung up on the raw speed of their code, and a certain machismo can be derived from shaving milliseconds off that pesky transaction that is the latest pride and joy. Often, this time is not very well spent. http://wldj.sys-con.com/read/117495.htmhttp://wldj.sys-con.com/read/117495.htm Mon, 08 Aug 2005 12:00:00 GMT The value of two phase commit transactions has always been that programmers can write applications that access data spread across multiple databases and be confident that any updates that are made will be consistently reflected in all of the databases, or none, at the end of the transaction. http://wldj.sys-con.com/read/102702.htmhttp://wldj.sys-con.com/read/102702.htm Tue, 21 Jun 2005 13:00:00 GMT In browsing around the Web, as one occasionally does in a free nanosecond, I read an interesting article about twp-phase commit transactions by Gregor Hohpe of ThoughtWorks ('Your Coffee Shop Does Not Use Two Phase Commit'). Gregor comes at the subject from the direction opposite the one I usually take in this column, since I am of a TP persuasion, but he covers the same arguments that I have explored in the past and comes to similar conclusions. http://wldj.sys-con.com/read/48218.htmhttp://wldj.sys-con.com/read/48218.htm Fri, 11 Feb 2005 00:00:00 GMT As I write, the noise level that continues to be generated around open source application servers and their claims to be coming into the world of enterprise computing continues. In my view, the main reason why the noise travels so far and seems so loud has nothing to do with the reality of the situation and everything to do with the media's love of controversy. http://wldj.sys-con.com/read/47099.htmhttp://wldj.sys-con.com/read/47099.htm Tue, 16 Nov 2004 00:00:00 GMT This issue, in an uncharacteristic attempt to fit in with the Zeitgeist, I propose to depart slightly from my well-trodden path to the transaction manager and take a look at frameworks. I expect you can guess which particular framework I am going to take a pass at, too. For nearly as long as there have been microprocessors, there have been frameworks. http://wldj.sys-con.com/read/46321.htmhttp://wldj.sys-con.com/read/46321.htm Fri, 10 Sep 2004 00:00:00 GMT A realization has dawned across the industry that 'service-oriented architecture' is a good thing. In fact, this is less of a dawning and more of a reawakening. http://wldj.sys-con.com/read/45564.htmhttp://wldj.sys-con.com/read/45564.htm Tue, 13 Jul 2004 00:00:00 GMT As we've discussed over the past few issues, JTA-style transactions provide a way for multiple data updates to be tied together so application logic can operate safely in the assumption that it will succeed or fail consistently, even in the face of technical failures along the road. http://wldj.sys-con.com/read/44849.htmhttp://wldj.sys-con.com/read/44849.htm Mon, 17 May 2004 00:00:00 GMT One definition of a commodity is something that you take for granted. I'll bet there aren't many readers out there who wake in the morning and exclaim, 'Thank goodness there's air in the room to breathe!' Likewise, computer users will seldom give thanks for their operating systems, a proclamation like 'praise be to those at AT&T and BSD for giving me Unix!' would likely raise more eyebrows than nods around an average water cooler. http://wldj.sys-con.com/read/44438.htmhttp://wldj.sys-con.com/read/44438.htm Fri, 09 Apr 2004 00:00:00 GMT This month's article is again inspired by a posting on the weblogic.developer.interest.transaction newsgroup. The question (excerpted from the posting) was: Does the 10 in weblogic-ejb-jar.xml apply to transactions that are in a suspended state? http://wldj.sys-con.com/read/44026.htmhttp://wldj.sys-con.com/read/44026.htm Wed, 10 Mar 2004 00:00:00 GMT Whatever your innermost feelings about the symbols, and however fondly you remember debugging network infrastructures with nothing more than a LAN sniffer and an uncanny ability to interpret 4k blocks of hex, it is fairly safe to say that Web services are here to stay. With the industry-wide support for the concept, and corresponding legions of emerging and released standards, they aren't going anywhere soon. http://wldj.sys-con.com/read/43815.htmhttp://wldj.sys-con.com/read/43815.htm Thu, 26 Feb 2004 00:00:00 GMT Another discussion based on a weblogic.developer.interest.transaction posting this month. It's a newsgroup that always proves to be a good source of information for the world at large when it comes to transactional behavior (and a good source of inspiration for me when the article time of the month rolls around again). http://wldj.sys-con.com/read/43052.htmhttp://wldj.sys-con.com/read/43052.htm Fri, 09 Jan 2004 00:00:00 GMT The launch of BEA's WebLogic Platform 8.1 was greeted with enthusiasm by industry analysts and IT practitioners alike, who recognized its potential to open up the power of the J2EE platform to a much broader spectrum of developers. http://wldj.sys-con.com/read/43038.htmhttp://wldj.sys-con.com/read/43038.htm Mon, 01 Dec 2003 00:00:00 GMT The buzz in the industry these days is all about service-oriented architecture. One of the key benefits that this brings is loose coupling between systems, which in turn improves the agility of the overall architecture http://wldj.sys-con.com/read/43020.htmhttp://wldj.sys-con.com/read/43020.htm Thu, 06 Nov 2003 15:24:00 GMT This month's article is again inspired by an interesting design discussion posted on the weblogic.developer.transaction newsgroup. (Ever get the feeling I'm running short of inspiration? Ideas for new articles always welcome!) http://wldj.sys-con.com/read/42998.htmhttp://wldj.sys-con.com/read/42998.htm Fri, 03 Oct 2003 00:00:00 GMT No, don't worry, it's not a a floor-wax/dessert-topping/toothpaste article this month; it's simply a look at how multilanguage application environments might be used together in highly distributed systems. http://wldj.sys-con.com/read/42978.htmhttp://wldj.sys-con.com/read/42978.htm Wed, 10 Sep 2003 13:50:00 GMT This month I was again inspired by the weblogic.developer.interest.transaction newsgroup on newsgroups.bea.com - if you weren't listening last time I plugged this newsgroup, listen now; one day, it might save your life! http://wldj.sys-con.com/read/42960.htmhttp://wldj.sys-con.com/read/42960.htm Thu, 07 Aug 2003 13:12:00 GMT In most large-scale 'mission critical' systems, high on the list of requirements is resistance to failure. With the world living in fear of violent destruction post 9/11, it is more common for the definition of 'failure' in this context to be the loss of a whole data-processing facility. http://wldj.sys-con.com/read/42767.htmhttp://wldj.sys-con.com/read/42767.htm Tue, 27 May 2003 00:00:00 GMT I have a rather deaf and rather elderly grandmother. She is a lovely woman and can spend hours telling tales - sometimes fascinating and sometimes... well, less fascinating - about times past. http://wldj.sys-con.com/read/42751.htmhttp://wldj.sys-con.com/read/42751.htm Tue, 22 Apr 2003 00:00:00 GMT Over the past 16 months - has it really been that long?! - I have attempted to climb the peaks of how to design applications that use transactions, and dived into the depths of the earth, looking at obscure knowledge such as how clients can demarcate transactions, and grubby details of interfacing WebLogic's transaction manager with external resources like MQ Series and, much to my surprise, you have come along on this odyssey with me. Who'd have thought that there were so many people interested in these minutiae? http://wldj.sys-con.com/read/42735.htmhttp://wldj.sys-con.com/read/42735.htm Thu, 27 Mar 2003 00:00:00 GMT I thought I would devote this month's column to a subject that appeared a while ago in the weblogic.developer.interest.transaction newsgroup on newsgroups.bea.com. As an opening comment, if you have never seen these newsgroups and you are a WebLogic developer, then go find them immediately! They're a mine of useful information, and a great place to get questions answered or collect opinions on design ideas or the like. http://wldj.sys-con.com/read/42825.htmhttp://wldj.sys-con.com/read/42825.htm Mon, 20 Jan 2003 00:00:00 GMT This month, I thought I would take a below-the-surface look at what needs to be done to achieve transactional access to the IBM MQSeries messaging product from WebLogic Server within the context of an Xa transaction managed by WebLogic's JTA subsystem. Of course, from the outset I would like to note that WebLogic Server itself boasts a very capable and reliable messaging system - which is getting more capable with every release - but it is a fact of life that MQseries for various reasons (most predating the existence of Java, never mind the JMS messaging standard) has a large installed base, so good interoperability with it is a requirement whatever your infrastructure religion. http://wldj.sys-con.com/read/42815.htmhttp://wldj.sys-con.com/read/42815.htm Tue, 17 Dec 2002 00:00:00 GMT A common complaint in the transaction newsgroup is, 'I've done my database updates in a JTA transaction, but they didn't complete as a unit!' In many cases, the explanation for this unfortunate loss of ACID is that the database connections that were used in the logic weren't obtained from a transactional data source, or Tx Data Source as it's abbreviated in the console. The shorthand explanation for this is that any database connection that is to participate in a distributed transaction needs to expose an xa interface, so you need a data source that can pass back an xa connection and that references a pool of xa database connections. http://wldj.sys-con.com/read/42808.htmhttp://wldj.sys-con.com/read/42808.htm Tue, 19 Nov 2002 00:00:00 GMT The waves of IT, as they are often called to, are marked out reasonably accurately by languages. Starting almost at the beginning, take COBOL. With its love of uppercase characters, and overly restrictive attitude to what column the uppercase characters appear in - not to mention its extraordinary zeal for the full stop - COBOL has always struck me as a language for programmers to use to shout at computers. http://wldj.sys-con.com/read/42797.htmhttp://wldj.sys-con.com/read/42797.htm Tue, 15 Oct 2002 00:00:00 GMT Picnicking during my summer holidays with my family, I was a little peeved to find that we had set up camp near an ant hill and some of them had decided to help themselves to elements of our lunch. Just as well, really, that I prefer sausage rolls and pork pies to chocolate buns, I guess. http://wldj.sys-con.com/read/42935.htmhttp://wldj.sys-con.com/read/42935.htm Tue, 24 Sep 2002 00:00:00 GMT Why are application servers so boring? I guess the answer to this question depends on your perspective. One man's boring commodity is another man's lifeblood. That observation alone would make for a rather short column, so we need another question. http://wldj.sys-con.com/read/42924.htmhttp://wldj.sys-con.com/read/42924.htm Fri, 23 Aug 2002 00:00:00 GMT As I may have mentioned once or twice in this column over the foregoing months, developers can derive a large amount of value from building their applications on an application server. http://wldj.sys-con.com/read/42902.htmhttp://wldj.sys-con.com/read/42902.htm Fri, 02 Aug 2002 00:00:00 GMT For several months now I've waxed lyrical about transactions and how they hide the complexities of distributed updates in applications, and indeed the concept of the two-phase commit transaction is a very powerful one, allowing you to make the assumption that all the transactional data stores that hold your business data will roll forward or back in lockstep. http://wldj.sys-con.com/read/42864.htmhttp://wldj.sys-con.com/read/42864.htm Mon, 20 May 2002 00:00:00 GMT I've seen several posts in the public WebLogic server transactions newsgroup in which people have had problems with transactions spread across multiple servers. The gist of these problems is always that they have two EJB components in two different servers. Bean One on Server One executes in the context of a JTA transaction in which it calls Bean Two on Server Two, thus propagating the transaction across to the second server. Finally, the first method ends, and the transaction commits. http://wldj.sys-con.com/read/42716.htmhttp://wldj.sys-con.com/read/42716.htm Wed, 17 Apr 2002 00:00:00 GMT That was what an old girlfriend periodically said to me. Needless to say, we're no longer together - I wasn't keen on the comparison. 'Shall I compare thee to a dog?' is rather less poetic than I like. But in thinking about this month's transaction column, the comment seemed strangely germane to the world of app servers and transactions. http://wldj.sys-con.com/read/42704.htmhttp://wldj.sys-con.com/read/42704.htm Tue, 26 Mar 2002 00:00:00 GMT As we've discussed over the past few issues, JTA-style transactions provide a way for multiple data updates to be tied together so application logic can operate safely in the assumption that it will succeed or fail consistently, even in the face of technical failures along the road. There are, however, times when you do not want all the work you do to succeed or fail in one big lump. http://wldj.sys-con.com/read/42686.htmhttp://wldj.sys-con.com/read/42686.htm Wed, 20 Feb 2002 00:00:00 GMT As I understand Western ideas about the world, there seem to have been three distinct phases through which they have passed. In the beginning, people believed that the world was flat, and at the center of the universe. Eventually, this view was confounded by the likes of Christopher Columbus discovering the New World while singularly failing to sail off the edge, as many were convinced he would do. http://wldj.sys-con.com/read/42669.htmhttp://wldj.sys-con.com/read/42669.htm Wed, 06 Feb 2002 00:00:00 GMT Sad, I mused - you don't often see that any more. My mind then wandered to hoping that, as technologists, we aren't somehow tacitly colluding in the erosion of the fabric that holds society together. Hmm, I seem to have come over all melancholy. Excuse me whilst I visit The Hunger Site… http://wldj.sys-con.com/read/42644.htmhttp://wldj.sys-con.com/read/42644.htm Mon, 07 Jan 2002 00:00:00 GMT Since this will be a monthly column on the subject of transactions, which from my experience seems to be a subject that everybody has heard of, but nobody is familiar with, I thought I would build up speed with a back-to-basics look at transactions, what they are and what they're for.