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

Related Topics: Weblogic

Weblogic: Article

Extending the J2EE Deployment API for Disruption-Free Service

WebLogic Server goes above and beyond the specification

Deployment Validation
This feature covers validating the deployment unit and runtime resources needed to deploy. The WebLogic Server Administration Console and WebLogic Workshop tools provide interactive phases of configuration, custom configuration, and pre-deployment validation. While deploying applications with these tools the user will be prompted for an option to configure/deploy and external resources that the application depends on.

For example, if an application depends on a JDBC Data Source the containers will check to see if that Data Source (and its corresponding connection pool) exists. If it doesn't exist, the user will be given the option to configure/deploy that resource. This includes the enhancements that are required in the Deployment API to incorporate the error details needed by the tools to create the missing resources or select suitable alternatives.

Production Redeployment The J2EE Deployment API outlines a basic redeployment strategy where older versions of the application will be replaced by the newer version. There's no mention about the state of HTTP sessions left in the container. In WebLogic Server 9.0 (Diablo) two redeployment strategies are provided.

WebLogic Server 9.0 introduces a controlled process for deploying new versions of Web applications without disrupting service. A new version of an application can be deployed alongside an existing version and WebLogic will gradually migrate all of the traffic to the new one. So when redeploying an existing application, the old version can be retired gracefully after all of the existing sessions end. If required, a time-out can also be set to retire the old version.

The new version immediately replaces the old version. This strategy is similar to what the J2EE Deployment API outlines.

WebLogic Server 9.0 can also roll back deployments.

WebLogic Server will automatically use the production redeployment strategy when the redeployed application version specifies a different version identifier from the currently deployed application version. A developer can assign a version identifier to an application by specifying it in the application's manifest file. The version identifier can also be assigned to an application during deployment or redeployment using the appversion option in the weblogic.Deployer tool.

Production redeployment can be done either through the administration console or through command-line tools such as weblogic.Deployer and WLST. When using the administration console in Diablo you start making changes by acquiring a lock over the config.xml configuration repository. The changes are left in a pending state and don't take effect until you activate them. This provides a predictable and secure way for distributing configuration changes in a domain. One has to click on the "Lock and Edit" button on the change center on the console to start deploying applications and finish by clicking the "Activate Changes" button on the change center.

When using the administration console the version identifier has to be configured on the application's manifest file. But the weblogic.Deployer tool can configure on the manifest file or specify using the -appversion option.

The weblogic.Deployer tool can also be used to redeploy a new version of an existing application. The old version can be retired by specifying the -retiretimeout option.

Understanding the Implications of Production Redeployment
By default, WebLogic Server destroys current user sessions when you redeploy a Web app. If you want to preserve the user sessions during redeployment, set "save-sessions-enabled" to "true" in the container-descriptor stanza of the weblogic.xml deployment descriptor file. Note, however, that the application still remains unavailable during the time the in-place redeployment takes place.

Testing Applications in Admin Mode
New application versions should to be tested before opening them to external clients. WebLogic Server puts an application in a special Administration Mode when you distribute a new version. External clients can't access applications that are in Admin Mode; an application is only available through an Administration Channel. An Administration Channel can be created in a domain by enabling the domain's Administration Port property. The default Administration Port is 9002. The Administration Channel is a secure channel that will accept only SSL connections. Once it is enabled in a domain all the administration traffic must go through that port.

For example, if a Web application (timeoff.war) with the context root "/timeoff" is deployed to a server in a domain with Administration Port 9002, then the application can be accessed by the URL https://serverhostname:9002/timeoff/.

If the testing yields successful results, the Web application can be started. Then external clients can access it through the regular listen ports configured for the targeted server(s). An application can also be started through tools like weblogic.Deployer or WLST.

Used along with side-by-side deployment or production redeployment, this feature can isolate the new application version. While the old version is still available to external clients without disruption, the new version can be sanity checked.

Module-Level Deployment and Redeployment for Enterprise Applications
WebLogic Server lets you target individual modules of an enterprise application at different server targets or deploy only a subset of available modules of the enterprise application. This provides flexible packaging options so you can bundle a group of related modules together in an enterprise application, but deploy only selected ones on individual servers or clusters in a domain.

This module-level targeting provides fine-grained control in deploying the modules. Module-level targeting can be done using any standard WebLogic deployment tool such as administration console, WLST, or weblogic.Deployer. This can simplify application packaging and distribution by packaging multiple modules in a single distributable EAR, but target only the modules you need to the right servers in a domain.

Module-level deployment using weblogic.Deployer:

java weblogic.Deployer -adminurl http://localhost:7001
-user weblogic -password weblogic
-name mywebapp -targets [email protected]
-stage -deploy c:\files\myApp.ear
Being able to do a live application upgrade is a major factor in achieving a disruption-free service along with other candidates like disruption-free server upgrade, improved visibility into runtime operations and the application runtime information, and flexible, customizable administration tools. With features in WebLogic Diablo like live server upgrades, diagnostic framework, automatic server migration, clustering, customizable administration console, and powerful scripting tools you can achieve a disruption-free service.

More Stories By Balamurali Kothandaraman

Balamurali Kothandaraman is a delivery technologist for education services at BEA Systems Inc. He has over 7 years of experience in Java and J2EE technologies and is a BEA Certified Server Specialist, Administrator, and Instructor. Bala is a frequent speaker at various conferences, including eWorld and JavaOne.

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
"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.
SYS-CON Events announced today that Conference Guru has been named “Media Sponsor” of the 22nd International Cloud Expo, which will take place on June 5-7, 2018, at the Javits Center in New York, NY. A valuable conference experience generates new contacts, sales leads, potential strategic partners and potential investors; helps gather competitive intelligence and even provides inspiration for new products and services. Conference Guru works with conference organizers to pass great deals to gre...
The Internet of Things will challenge the status quo of how IT and development organizations operate. Or will it? Certainly the fog layer of IoT requires special insights about data ontology, security and transactional integrity. But the developmental challenges are the same: People, Process and Platform. In his session at @ThingsExpo, Craig Sproule, CEO of Metavine, demonstrated how to move beyond today's coding paradigm and shared the must-have mindsets for removing complexity from the develop...
In his Opening Keynote at 21st Cloud Expo, John Considine, General Manager of IBM Cloud Infrastructure, led attendees through the exciting evolution of the cloud. He looked at this major disruption from the perspective of technology, business models, and what this means for enterprises of all sizes. John Considine is General Manager of Cloud Infrastructure Services at IBM. In that role he is responsible for leading IBM’s public cloud infrastructure including strategy, development, and offering m...
"Evatronix provides design services to companies that need to integrate the IoT technology in their products but they don't necessarily have the expertise, knowledge and design team to do so," explained Adam Morawiec, VP of Business Development at Evatronix, in this SYS-CON.tv interview at @ThingsExpo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
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 ...
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.
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.
"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.
"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...
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...
22nd International Cloud Expo, taking place June 5-7, 2018, at the Javits Center in New York City, NY, and co-located with the 1st DXWorld Expo will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud ...
"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...
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...
"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 ...