Archive for the ‘WebLogic’ Category

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Decomposition of legacy Java EE applications using containers

Together with growing demand in PaaS and DevOps solutions, we can notice a set of adoption barriers for the owners of legacy applications hosted inside VMs or just on top of bare metal servers. The complexity of decomposition and migration processes is often very high. Usually, application owners have to redesign their application architecture in order to benefit from the modern PaaS and CaaS solutions.

In this article, we will analyze the specific challenges of migrating Java legacy applications that are running inside VMs to container based platforms. And using the example of Oracle WebLogic Server, we’ll show the exact steps of decomposition process and the outcome of this migration.

Motivation for Migration to Containers

Hardware virtualization was a great step forward in the hosting of Java EE applications compared to the era of Bare Metal. It gave us the ability to isolate multiple applications from each other and utilize hardware more efficiently. However, with Hypervisors, each VM requires its own full OS, TCP and file system stacks, which uses significant processing power and memory of the host machine.

Each VM has a fixed amount of RAM and only some hypervisors can resize VMs while running with a help of memory ballooning that is not a trivial task. As a result, usually we reserve resources in each VM for the further scaling of the application. These resources are not fully utilized and, at the same time, they cannot be shared with other applications due to the lack of proper instances isolation inside a VM.

Containers take performance and resource utilization a step further by sharing the OS kernel, TCP stack, file system and other system resources of the host machine while using less memory and CPU overhead. Read the complete article here.

WebLogic Partner Community

For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center.

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Technorati Tags: WebLogic Community,Oracle,OPN,Jürgen Kress

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RESTFul Management Services are really powerful in terms of monitoring your Oracle WebLogic Server Domain, but you can also use RESTFul Management Services to control your Oracle WebLogic Server Domain. RESTFul Management Services are enabling you to startup, suspend, resume and shutdown for example your Managed Servers.
All what you need is cURL, the Admin User and Password of your Oracle WebLogic Server, Hostname of your Oracle WebLogic Domain and the Port of your AdminServer. Read the complete article here.

WebLogic Partner Community

For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center.

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Technorati Tags: WebLogic Community,Oracle,OPN,Jürgen Kress

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Not wanting to be left out of all the fun, here’s my contribution for Tim Hall’s OTN Appreciation Day event

For those of us that came from an Oracle Application Server (iAS/OC4J) background, and with maybe a particular OCD-style bent for automation, I think the the biggest discovery in WebLogic Server was WLST, or WebLogic Scripting Tool. This lets you access the underlying JMX management objects that control every facet of WebLogic via an easy to use tool Python (or, rather Jython, the java variant). Python itself is fairly popular these days but nearly 10 years ago it was a bit of a novelty for me but gave me lots more scripting flexibility and control compared to traditional shell script.

Anyway, for a couple of years I was touting a presentation called "WLST – WebLogic’s Swiss Army Knife!" extolling the tool’s virtues!

In short:

  • anything you can do "clicky-clicky" in the WebLogic console (and more!) you can do in a WLST script,
  • you can even record WLST, like you might for an MS Word macro, when you do some manual commands in the console (or EM FMWC these days) to give yourself a starting script to tweak,
  • Python gives you a rich programming environment for building modular scripts using helpful language constructs,
  • WLST can be used online or offline (which means with the Admin Server running or not) – offline a bit more restrictive but allows you to build pretty comprehensive configurations without running the server software itself,
  • WLST can be used for both configuring the WebLogic domain, as well as monitoring it when it’s up (for example checking the number of messages in a JMS queue or connections in a data source pool),
  • Fusion Middleware products come with WLST libraries, e.g. Oracle SOA Suite includes WLST utilities for deploying composites. Read the complete article here.

WebLogic Partner Community

For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center.

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In October 2014, we delivered Oracle WebLogic Server 12.2.1 as part of the overall Oracle Fusion Middleware 12.2.1 Release and October 2015 we delivered the first patch set release 12.2.1.1. This week, the second patch set 12.2.1.2 is available.   New WebLogic Server 12.2.1.2 installers are now posted on the Oracle Technology Network and Oracle Software Delivery Cloud, and new documentation has been made available. There are a couple of new datasource features hidden there. One of them is called “gradual draining.”

When planned maintenance occurs on an Oracle RAC configuration, a planned down service event is processed by an Active GridLink data source using that database. By default, all unreserved connections in the pool are closed and borrowed connections are closed when returned to the pool.  This can cause an uneven performance because:

· New connections need to be created on the alternative instances.

· A logon storm on the other instances can occur.

It is desirable to gradually drain connections instead of closing them all immediately. The application can define the length of the draining period during which connections are closed. It is configured using the weblogic.jdbc.drainTimeout value in the connection properties for the datasource. As usual, it can be set in the console, EM, or WLST. The following figure shows the administration console.

The result is that connections are closed in a step-wise fashion every 5 seconds. If the application is actively using connections, then they will be created on the alternative instances at a similar rate. The following figure shows a perfect demonstration of draining and creating new connections over a 60 second period using a sample application that generates constant load.  Without gradual draining, the current capacity on the down instance would drop off immediately similar to the LBA percentages and connections would be created on the alternative instance as quickly as possible. Read the complete article here.

WebLogic Partner Community

For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center.

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Technorati Tags: WebLogic Community,Oracle,OPN,Jürgen Kress

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Short overview of some last week failing builds at our site

Since a while ago it’s possible to register proxy repositories in Nexus based on the Oracle Maven Repository.
To be able to proxy this repository you need to make use of an oracle account for the autenthication before you can download the artifact.

Let’s check the logging to understand what it does (i can rephrase the logfile or just copy/paste it ;), when others google for it it will find the hit much easier). Read the complete article here.

WebLogic Partner Community

For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center.

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Technorati Tags: WebLogic Community,Oracle,OPN,Jürgen Kress

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Undeniably, microservices is an extremely hot term. A bandwagon almost every product team at Oracle seems eager to be jumping on to. It is hard to give a concise and objective definition of what microservices are. Through microservices, organizations try to achieve more agility, quicker and more reliable application development and delivery at scale. This is especially relevant for the systems of innovation – where change in functionality and scale is the main constant – as opposed to systems of record that run the existing business operations and do not require that same breakneck pace of change.

Microservices are standalone components with a single responsibility, owned by a single team and can be built, tested, deployed and scaled on their own. They are stateless – although they certainly can use a data store for their own data. Ideally, communication between microservices is done as decoupled as can be: through events or at least through asynchronous calls routed through proxy endpoints.

Microservices are products, not projects – they have a life cycle but not a project end date. Teams are small, can own multiple microservices and not only build them but also run them: full responsibility for Dev & Ops, through the entire lifecycle of the microservice. Teams are very independent as well: for example enterprise wide canonical models and a central corporate database are very much not part of the philosophy, and at least some leeway in making technology decisions and certainly to pick development tools is required. Standardizing is very useful on mechanisms for common tasks such as defining and cataloging APIs, doing source code control and handling incoming requests and inter-service communication.

To make microservices work – a lot of automation is required, around build, test (if nothing else then at least regression testing) , delivery, scaling and monitoring. In a microservice, there is no clear distinction between the custom built functionality and custom configured platform components – whether you reuse or buy or build the pieces that together make up the microservice is irrelevant. The team that assembles the microservice in its box has ownership of the entire box.

Very valuable are the slides from the presentation by Luis Weir (Oracle ACE Director, CapGemini) and Robert Wunderlich (Senior Principal Product Management at Oracle Corporation) at Oracle OpenWorld 2016.This next figure was taken from this presentation. It visualizes the operating model for a microservices architecture – showing many of the aspects discussed overhead:

The format of the microservice box is frequently a container – especially a Docker container – that contains all required pieces to run and manage the microservice. Read the complete article here.

WebLogic Partner Community

For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center.

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The Oracle Application Development Cloud Platform Specialization recognizes partners who are proficient in selling, developing and deploying Oracle’s Application Development Cloud Platform-based solutions. This specialization covers the following services: Oracle Java Cloud Service, Oracle Developer Cloud Service, Oracle Application Container Cloud and Oracle Application Builder Cloud Service. Check out the Oracle Cloud Platform as a Service (PaaS) KnowledgeZone and the specialization criteria page for more details.

WebLogic Partner Community

For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center.

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