Weblogic Authors: Yeshim Deniz, Elizabeth White, Michael Meiner, Michael Bushong, Avi Rosenthal

Related Topics: Weblogic

Weblogic: Article

Transactions: Driving You to Distraction?

Choose The Type 2 Driver To Help

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. Things that are taken so much for granted are ripe for methods such as open source as provisioning mechanisms - at the end of the day, if its interfaces are well known and an implementation works "well enough" and is supported, then who cares if it was written in a garage or a high-tech lab? That's one of the reasons why I think the application server has some way to go before it commoditizes to the point where open source provides a realistic alternative as an underpinning to a business critical deployment - the application server market is small, and the capabilities offered by the market leading app. Servers are too rich (and the standards are evolving too quickly) for that to happen just yet a while.

But I digress (although I'm not sure if it's possible to digress before you have actually started...). This month's article is about a piece of technology that exists somewhere in the twilight zone between commodity and valuable asset - the humble JDBC driver.

One of the main drivers for the widespread adoption of the J2EE platform was the existence of standards that provide a good degree of plug-and-playability in terms of the resources accessing and accessed by the platform. One such principal resource is the SQL database (whose adoption in its own life cycle was fueled by the standard relational model for data access providing some swapability at a different layer of the architecture). The Java standard that makes SQL databases pluggable at this level is, of course, JDBC. At a brief glance, you may be wondering what I am going to write about next, apparently being on the verge of saying that the JDBC driver is yet another commodity, but actually, the truth is, especially in the context of XA transactions, all JDBC drivers were not created equal. My intent this month is to dig a bit deeper into this, and help answer two questions: What's the overhead of XA and what JDBC driver should I use to access my Oracle database in an XA transaction?

What's the Overhead of XA?
Quite a few years ago, when X/Open first created the XA standard, there were no commercial databases that supported it. Then came Oracle 7 (and the other RDBMS products of around the same vintage) and XA moved from nice theory to realistic deployment option and the distributed transaction was finally liberated from the mainframe to roam free across the world of open systems. In those days, it was not unreasonable advice to suggest that architects build all their services to access the database via XA. The performance overhead of XA was small (I dimly remember figures of 5% bandied about) and the 1pc optimization built into Tuxedo (and later brought forward into BEA WebLogic Server's transaction manager) meant that the 5% was all you paid, if you didn't need a distributed transaction for any particular use-case.

These days, the world has moved on, and this advice is in need of amendment - it turns out that with recent versions of Oracle, and Java in the picture, the overhead of accessing the database via XA is considerably more than 5% - some benchmarks put the degradation in throughput caused by using XA as high as 15x in the worst case (and note, this is not the overhead of two-phase commit, simply overhead introduced by the DBMS engine as a result of using xa_begin and xa_commit to delineate transactions).

Clearly, the prudent advice to anyone architecting a J2EE system is, at the very least, to benchmark your application using the XA configuration you need for production to ensure that your exact setup will give the throughput you require from your application, and be prepared to segment your database accesses into those that can use database local transactions and those that require XA for synchronisation with resources external to the database (for example, once and once only guaranteed message delivery from transactional message queues).

What JDBC Driver Should I Use to Access Oracle?
The JDBC standard provides for four different "types" of JDBC drivers. The important ones for this discussion are type 2 (in which the database is accessed via JNI calls from the java layer to Oracle's native OCI libraries) and type 4 (in which a pure Java driver implementation talks across a socket to a remote server, which accesses the database as a proxy for the client)

Looking at this from a "commodity component" perspective, the choice between the type 2 and type 4 drivers might be expected to be academic (with perhaps a slight preference for type 4, given that this doesn't require installation of the database native components on your application server box). This is by and large the case for non-XA database access; however, for XA access the story is somewhat different. In this case, the throughput of the type 2 drivers is somewhat better than that of their type 4 equivalents, but more pronounced is the effect on the database CPU - XA access via the type 4 driver causes dramatically increased CPU utilization on the database server relative to the type 2 equivalent.

So, What's the Conclusion?
As with all performance-type considerations, the main conclusion has to be that you should performance test an exact replica of your intended production configuration in order to determine that its performance will meet your needs. Any benchmark or other comparison of that kind is inherently heavily influenced by the usage patterns of the application, and also any benchmark is a snapshot in time of the state of the system - patches or new releases of the driver code (or the database engine itself) could completely change (hopefully for the better!) the results of any comparison.

However, with the technology where it is today, it seems safe to conclude that you should try to stick to the type 2 driver for XA database access, unless you have a pretty compelling reason to do otherwise.

More Stories By Peter Holditch

Peter Holditch is a senior presales engineer in the UK for Azul Systems. Prior to joining Azul he spent nine years at BEA systems, going from being one of their first Professional Services consultants in Europe and finishing up as a principal presales engineer. He has an R&D background (originally having worked on BEA's Tuxedo product) and his technical interests are in high-throughput transaction systems. "Of the pitch" Peter likes to brew beer, build furniture, and undertake other ludicrously ambitious projects - but (generally) not all at the same time!

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.

@ThingsExpo Stories
"Akvelon is a software development company and we also provide consultancy services to folks who are looking to scale or accelerate their engineering roadmaps," explained Jeremiah Mothersell, Marketing Manager at Akvelon, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
In his session at 21st Cloud Expo, Carl J. Levine, Senior Technical Evangelist for NS1, will objectively discuss how DNS is used to solve Digital Transformation challenges in large SaaS applications, CDNs, AdTech platforms, and other demanding use cases. Carl J. Levine is the Senior Technical Evangelist for NS1. A veteran of the Internet Infrastructure space, he has over a decade of experience with startups, networking protocols and Internet infrastructure, combined with the unique ability to it...
"Space Monkey by Vivent Smart Home is a product that is a distributed cloud-based edge storage network. Vivent Smart Home, our parent company, is a smart home provider that places a lot of hard drives across homes in North America," explained JT Olds, Director of Engineering, and Brandon Crowfeather, Product Manager, at Vivint Smart Home, in this SYS-CON.tv interview at @ThingsExpo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
"IBM is really all in on blockchain. We take a look at sort of the history of blockchain ledger technologies. It started out with bitcoin, Ethereum, and IBM evaluated these particular blockchain technologies and found they were anonymous and permissionless and that many companies were looking for permissioned blockchain," stated René Bostic, Technical VP of the IBM Cloud Unit in North America, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Conventi...
Gemini is Yahoo’s native and search advertising platform. To ensure the quality of a complex distributed system that spans multiple products and components and across various desktop websites and mobile app and web experiences – both Yahoo owned and operated and third-party syndication (supply), with complex interaction with more than a billion users and numerous advertisers globally (demand) – it becomes imperative to automate a set of end-to-end tests 24x7 to detect bugs and regression. In th...
Large industrial manufacturing organizations are adopting the agile principles of cloud software companies. The industrial manufacturing development process has not scaled over time. Now that design CAD teams are geographically distributed, centralizing their work is key. With large multi-gigabyte projects, outdated tools have stifled industrial team agility, time-to-market milestones, and impacted P&L stakeholders.
"Cloud Academy is an enterprise training platform for the cloud, specifically public clouds. We offer guided learning experiences on AWS, Azure, Google Cloud and all the surrounding methodologies and technologies that you need to know and your teams need to know in order to leverage the full benefits of the cloud," explained Alex Brower, VP of Marketing at Cloud Academy, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clar...
Widespread fragmentation is stalling the growth of the IIoT and making it difficult for partners to work together. The number of software platforms, apps, hardware and connectivity standards is creating paralysis among businesses that are afraid of being locked into a solution. EdgeX Foundry is unifying the community around a common IoT edge framework and an ecosystem of interoperable components.
"MobiDev is a software development company and we do complex, custom software development for everybody from entrepreneurs to large enterprises," explained Alan Winters, U.S. Head of Business Development at MobiDev, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
Coca-Cola’s Google powered digital signage system lays the groundwork for a more valuable connection between Coke and its customers. Digital signs pair software with high-resolution displays so that a message can be changed instantly based on what the operator wants to communicate or sell. In their Day 3 Keynote at 21st Cloud Expo, Greg Chambers, Global Group Director, Digital Innovation, Coca-Cola, and Vidya Nagarajan, a Senior Product Manager at Google, discussed how from store operations and ...
"There's plenty of bandwidth out there but it's never in the right place. So what Cedexis does is uses data to work out the best pathways to get data from the origin to the person who wants to get it," explained Simon Jones, Evangelist and Head of Marketing at Cedexis, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
SYS-CON Events announced today that CrowdReviews.com has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5–7, 2018, at the Javits Center in New York City, NY. CrowdReviews.com is a transparent online platform for determining which products and services are the best based on the opinion of the crowd. The crowd consists of Internet users that have experienced products and services first-hand and have an interest in letting other potential buye...
SYS-CON Events announced today that Telecom Reseller has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5-7, 2018, at the Javits Center in New York, NY. Telecom Reseller reports on Unified Communications, UCaaS, BPaaS for enterprise and SMBs. They report extensively on both customer premises based solutions such as IP-PBX as well as cloud based and hosted platforms.
It is of utmost importance for the future success of WebRTC to ensure that interoperability is operational between web browsers and any WebRTC-compliant client. To be guaranteed as operational and effective, interoperability must be tested extensively by establishing WebRTC data and media connections between different web browsers running on different devices and operating systems. In his session at WebRTC Summit at @ThingsExpo, Dr. Alex Gouaillard, CEO and Founder of CoSMo Software, presented ...
WebRTC is great technology to build your own communication tools. It will be even more exciting experience it with advanced devices, such as a 360 Camera, 360 microphone, and a depth sensor camera. In his session at @ThingsExpo, Masashi Ganeko, a manager at INFOCOM Corporation, introduced two experimental projects from his team and what they learned from them. "Shotoku Tamago" uses the robot audition software HARK to track speakers in 360 video of a remote party. "Virtual Teleport" uses a multip...
A strange thing is happening along the way to the Internet of Things, namely far too many devices to work with and manage. It has become clear that we'll need much higher efficiency user experiences that can allow us to more easily and scalably work with the thousands of devices that will soon be in each of our lives. Enter the conversational interface revolution, combining bots we can literally talk with, gesture to, and even direct with our thoughts, with embedded artificial intelligence, whic...
SYS-CON Events announced today that Evatronix will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Evatronix SA offers comprehensive solutions in the design and implementation of electronic systems, in CAD / CAM deployment, and also is a designer and manufacturer of advanced 3D scanners for professional applications.
Leading companies, from the Global Fortune 500 to the smallest companies, are adopting hybrid cloud as the path to business advantage. Hybrid cloud depends on cloud services and on-premises infrastructure working in unison. Successful implementations require new levels of data mobility, enabled by an automated and seamless flow across on-premises and cloud resources. In his general session at 21st Cloud Expo, Greg Tevis, an IBM Storage Software Technical Strategist and Customer Solution Architec...
To get the most out of their data, successful companies are not focusing on queries and data lakes, they are actively integrating analytics into their operations with a data-first application development approach. Real-time adjustments to improve revenues, reduce costs, or mitigate risk rely on applications that minimize latency on a variety of data sources. In his session at @BigDataExpo, Jack Norris, Senior Vice President, Data and Applications at MapR Technologies, reviewed best practices to ...
An increasing number of companies are creating products that combine data with analytical capabilities. Running interactive queries on Big Data requires complex architectures to store and query data effectively, typically involving data streams, an choosing efficient file format/database and multiple independent systems that are tied together through custom-engineered pipelines. In his session at @BigDataExpo at @ThingsExpo, Tomer Levi, a senior software engineer at Intel’s Advanced Analytics gr...