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[C++] What warning C4291 is and how to deal with it

2018-09-11T09:21:00.000+03:00

After Java, C++ impresses me with his manual memory management and the idea of how many surprises a developer may meet on his/her way. For example, if you define your own operator new with custom arguments (it is called "class-specific placement allocation functions"), a placement form of operator delete that matches the placement form of operator new has to be defined (the corresponding form of the delete operator must have the signature void operator delete(void *ptr, user-defined-args...)). When an exception is thrown in a class constructor the placement form of operator delete will be invoked and take care of the memory reclaimation. If there is no the placement form of the operator, no one will be able to take care of the memory and a memory leak occurs.

Warning C4291

Fortunately, the MSVC compiler lets us know about the dangerous using warning C4291 no matching operator delete found; memory will not be freed if initialization throws an exception (please, compile the code with /EHsc /W1). Let's have a look:

[1/2] Building CXX object src\memory\CMakeFiles\placement-new-delete.dir\PlacementNewDelete.cpp.obj
..\src\memory\PlacementNewDelete.cpp(67): warning C4291: 'void *MyClassA::operator new(size_t,MyAllocator &)': no matching operator delete found; memory will not be freed if initialization throws an exception
..\src\memory\PlacementNewDelete.cpp(32): note: see declaration of 'MyClassA::operator new'
[2/2] Linking CXX executable src\memory\placement-new-delete.exe

The warning is described in detail there: Compiler Warning (level 1) C4291 (MSDN).

The problem you can be faced is the following: in some cases, it's not so easy to implement the placement form of operator delete. Operator new forewer takes the size argument - the ammount of memory required for the object while operator delete doesn't but the argument may be necessary to allocate the memory and return it to the operating system then.

Writing your own allocator

Let's consider the following pattern: a third-party memory allocator is used to allocate memory for objects, the allocator has two methods: allocate and deallocate and each method takes a size_t size parameter. I see this code very often through the Eclipse OMR JIT compiler, so I believe the pattern is quite popular.

Build Custom Passes as a Part of the LLVM Build Environment

2018-05-23T10:26:00.000+03:00

There is no dynamic linking on Windows (this is OS weirdness) so we cannot use the plugins at all, unfortunately. In this post, I would like to share a how-to about building your own LLVM pass as a part of the LLVM build tree (LLVMExperimentPasses and the demo pass FunctionArgumentCount can be found on GitHub).

To build the pass, do the following:

1. Copy the LLVMExperimentPasses pass directory in the lib/Transforms one. Here and throughout, all paths are given at the root of the LLVM source directory.

2. Add the add_subdirectory(LLVMExperimentPasses) line into lib/Transforms/CMakeLists.txt

3. For each implemented pass, add a function named initialize${THE_NAME_OF_THE_PASS}Pass(PassRegistry &); into the include/llvm/InitializePasses.h header file. Also add the funtion void initializeLLVMExperimentPasses(PassRegistry &); there. For example, for the FunctionArgumentCount pass add the following lines:

// my experiment passes
void initializeLLVMExperimentPasses(PassRegistry &);
void initializeFunctionArgumentCountPass(PassRegistry &);
} // end namespace llvm

(the functions must be defined inside the llvm namespace).

4. Add the LLVMExperimentPasses library to the LLVM_LINK_COMPONENTS list in the tools/opt/CMakeLists.txt file:

set(LLVM_LINK_COMPONENTS
    ${LLVM_TARGETS_TO_BUILD}
    AggressiveInstCombine
    ...
    ExperimentPasses
)

Note: The form of ExperimentPasses, not LLVMExperimentPasses is used here.

5. Register the passes into the opt tool by adding an invocation of the initializeLLVMExperimentPasses function to the main method of the tool (file tools/opt/opt.cpp):

// Initialize passes
PassRegistry &Registry = *PassRegistry::getPassRegistry();
initializeCore(Registry);
...
initializeLLVMExperimentPasses(Registry);
// For codegen passes, only passes that do IR to IR transformation are
// supported.

6. Rebuild LLVM (YOUR_LLVM_BUILDTREE is the directory where you build LLVM) and install the new output files:

cd YOUR_LLVM_BUILDTREE

cmake -DCMAKE_CXX_COMPILER=YOUR_FAVOURITE_COMPILER \
-DCMAKE_C_COMPILER=YOUR_FAVOURITE_COMPILER \
-DCMAKE_LINKER=YOUR_FAVOURITE_LINKER .. -G"Ninja"

cmake --build .

cmake --build . --target install

The passes are ready. For instance, the FunctionArgumentCount pass is registered as fnargcnt in the opt tool and can be invoked using the following command line:

opt.exe -fnargcnt < sum.bc > sum-out.bc

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IBM OpenSources Itself: Build the OpenJ9 JVM into Docker Image from Sources Using Ansible

2018-02-21T08:17:00.001+03:00

IBM has opened their products to the open source community. Today I wish to tell you about two of that products:

OpenLiberty - open sourced Java EE application server WebSphere Liberty Profile
OpenJ9 - open sourced JVM based on OpenJDK and another open source project OMR that contains cross platform components for building reliable, high performance language runtimes (so, not only the Java runtime but runtimes for Python, Ruby and other languages).

OpenJ9 and OMR are opened under the umbrella of Eclipse Foundation.

Let's try to build the JVM. Thanks to the developers, there is a full instruction how to build the project using Docker and the Make utility. The instruction for JDK 8 can be found here: Build_Instructions_V8.md while the instruction for JDK 9 is here: Build_Istructions_V9.md. Both instructions contain a part for a build process based on Docker. Really, this is very usable just build a Docker-container which contains all required dependencies: C and C++ libraries, python libraries, a compiler collection, and tools don't have to be installed on the host environment, we can just to isolate them within a container.

Integration Testing a Java EE Application in the Containerized World Using Kubernetes and the Fabric8 Maven Plugin

2017-12-22T15:49:00.000+03:00

Kubernetes is an open-source system for automating deployment, scaling, and management of containerized applications. With Kubernetes, you are able to quickly and efficiently respond to customer demand:

Deploy your applications quickly and predictably
Scale your applications on the fly
Roll out new features seamlessly
Limit hardware usage to required resources only

Fabric8 Maven plugin is a one-stop-shop for building and deploying Java applications for Docker, Kubernetes and OpenShift. It brings your Java applications on to Kubernetes and OpenShift. It provides a tight integration into Maven and benefits from the build configuration already provided. It focuses on three tasks:

Building Docker images
Creating OpenShift and Kubernetes resources
Deploy application on Kubernetes and OpenShift

My demo Java EE application uses the Fabric8 Maven plugin as an access point to Kubernetes: the application can be deployed on a WebSphere Liberty-based docker container running inside a Kubernetes cluster and the integration tests run dependent on the containerized application. Since the environment is containerized, any databases, messaging providers or other infrastructure components can be taken into account in the future also using appropriate containers.

The fabric8-maven-plugin configuration for the application:

IBM Cloud Private Café in Moscow

2017-12-11T12:57:00.001+03:00

I would like to thank my ex-colleagues from the IBM Russia/CIS office from Moscow for a chance to attend an amazing event - IBM Cloud Private Café - and meet a new cloud offering from IBM.

In this post, I wish to say a couple of words about this new product from the Big Blue.

So, IBM Cloud Private:

Software defined, not an appliance (as, for example, Oracle Private Cloud Applience), positioned as a pure software defined solution which can be installed upon x86-64, Power or z Systems.
Container-based, Kubernetes is the heart of the product.
IBM provides the catalog of modernized and containerized IBM Middleware and data services (so, you can run your IBM WebSphere Liberty or Node.js based microservice in a Kubernetes-managed Docker container).
IBM extends Kubernetes by the following capabilities: Intelligent Scheduling, Self-healing, Horizontal scaling, Simplified cluster management, Container security & isolation, etc.
Cloud Foundry for application development and deployment is accessible out of the box.
Integrated DevOps toolchain may be interesting for developers.
IBM Cloud Private may be your secure access point to public cloud services (Blockchain, AI - Watson, etc.)
The cloud is running on existing IaaS: wmware, openstack, Power Systems, System z, IBM Spectrum, etc.

There are three versions of IBM Cloud Private:

Community Edition (exactly one master + one cluster, can be installed for free by downloading images from Docker Hub but, as you understand, no support is provided. The large list of IBM software with the suffix "for Developers" is also available.
Cloud Native (the fault-tolerant master, the support is provided, Community Edition + Cloud Foundry (optional) + IBM Enterprise Software (Microservice Builder, WebSphere Liberty, IBM SDK for Node.js, Cloud Automation Manager, etc.)
Enterprise (the fault-tolerant master, the support is provided, Cloud Native + WAS ND + MQ Advanced + API Connect Professional + Db2 Direct Advanced (sep. PN) + UrbanCode Deploy (sep. PN)).

IBM Cloud Private addresses the following enterprise use cases:

Case 1: Modernize and optimize existing applications (monolithic WebSphere or WebLogic based applications, existing WAS, MQ, DB2 infrastructure) + DevOps initiatives.
Case 2: Opening up enterprise data centres to work with public cloud services (e.g., IBM Watson, Blockchain and others).
Case 3: Create new cloud-native applications and push them to a namespace in the private cloud: addressing new use cases, IoT, Blockchain, Machine Learning, Data science experience, building MicroServices.

To have access to IBM Cloud Container Service, only an IBM Bluemix account is needed. The service is a container-based public cloud and can be used as a production environment as well as a place where environments are created by demand for development and testing before pushing images to your private cloud.

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Deploy a Custom WebSphere Liberty Runtime with the MicroProfile 1.2 Feature in IBM Cloud

2017-11-23T16:53:00.001+03:00

WebSphere Liberty is a fast, dynamic, and easy-to-use Java application server, built on the open source Open Liberty project. Ideal for developers but also ready for production, on-premise or in the cloud.

IBM Bluemix (is now IBM Cloud) is the latest cloud offering from IBM. It enables organizations and developers to quickly and easily create, deploy, and manage applications on the cloud. Bluemix is an implementation of IBM's Open Cloud Architecture based on Cloud Foundry, an open source Platform as a Service (PaaS). IBM Cloud Foundry includes runtimes for Java, Node.js, PHP, Python, Ruby, Swift and Go; Cloud Foundry community build packs are also available.

Although IBM Cloud has already provided a runtime engine for WebSphere Liberty, sometimes this isn't enough and developers may need their own version of the platform, i.e. a lightweight version based on Liberty Kernel, or an old version to ensure backward compatibility, or the version of WebSphere Liberty armed with a set of features specific for the developed application.

The blog post provides a demonstration of how to deploy your own installation of WebSphere Liberty to IBM Cloud as a usual Java application. The deployed installation is armed with the latest version of MicroProfile, an open forum to collaborate on Enterprise Java Microservices, issued on October 3, 2017.

Eclipse MicroProfile 1.2 is built on the 1.1 version and updates the config API and adds the health check, fault tolerance, metrics, and JWT propagation APIs. As stated on the official page of the project, the goal of MicroProfile is to iterate and innovate in short cycles, get community approval, release, and repeat. Eventually, the output of this project could be submitted to the JCP for possible future inclusion in a Java JSR (or some other standards body). The WebSphere Liberty application server implements Microprofile 1.2, just the corresponding feature -
microprofile-1.2 - must be included in the server.xml configuration file.

ESB vs EAI: "Universal Service", What is Wrong with This Pattern

2017-10-13T16:46:00.002+03:00

Some technical people do understand the Enterprise Service Bus (ESB) concept as a universal channel designed just to enable some XML messages encoded as plain string transmission among enterprise applications. The channel should provide no validation/enrichment/monitoring capabilities, the channel is considered only as a dumb message router that also provides message transformation into an accessible for the enterprise applications format. A powerful and expensive integration middleware, like Oracle Service Bus, Oracle SOA Suite, IBM Integration Bus, or SAP PI/XI, is chosen as a platform for the integration solution. Usually, it's required that the IT team should be able to configure new or existing routes just by edit a few records in the configuration database.

The developers of such "universal solution" believe that a new application can be connected to the solution just by design an appropriate adapter and insert a few records into the configuration database.

In fact, the developers have to implement a number of integration patterns and, optionally, a canonical data model using a small subset of the capabilities provided by the integration platform.

The focus of the article is to explain why the above approach is not effective and why developers have to leverage as many capabilities of their preferable middleware platform as possible.

Threads in Managed Environments. Work Managers

2017-10-03T12:07:00.001+03:00

We pay for modern application servers since they provide a managed environment for our applications. An application server implements some APIs, for example Java EE 7 or Java EE 8, as well as provides some capabilities such as application life-cycle management, transaction management, resource access and thread management.

Thread pool

An application server uses a thread pool to provide the thread management capability. While an application deployed on the server works, an application thread isn't created when a new request is accepted but taken from the pool. This approach protects the server from creating a lot of threads and overwhelming the operating system by the duty to process too many threads. The goal has been pursued through blocking accepted requests if there are no threads in the pool.

The IT team can specify the following parameters of the thread pool:

thread priority - ranges threads created by a number of pools by priority. A user request to a business critical application hangs other threads in the system.
number of threads - limits the number of concurrent threads executing requests. Modern application servers, for example Oracle WebLogic, let us set up the limit not only as a constant value but also as a reference to a data source so the maximum number of thread would be equal to the capacity of the connection pool related to the data source. On thread gets a connection to the database.

The application server takes into account the above parameters in cooperation with some inner optimizations by analyzing the current workload, the number of available processors and the amount of free memory.

Exposing Servlet- and JAX-RS-based WebSphere Liberty REST APIs with Swagger

2017-09-08T11:17:00.000+03:00

An amazing article Developing a Swagger-enabled REST API using WebSphere Developer Tools demonstrates how to expose a usual servlet as a REST API using a new feature of WebSphere Liberty called apiDiscovery-1.0.

I've rewritten a bit the code of the servlet taking the JSR 353/JSON-P API into account and eliminated all WebSphere-related code, so the demonstration project can be built using Apache Maven: just put the 'javax.json:javax.json-api:jar' dependency into your pom.xml.

Including a swagger.json or swagger.yaml file inside the corresponding META-INF folder is the easiest way to expose the documentation of web modules, but not the only one. If the web application does not provide a swagger.json or swagger.yaml file and the application contains JAX-RS annotated resources, the Swagger document would be automatically generated. As mentioned in the official documentation, the server configuration must have the apiDiscovery-1.0 feature and the jaxrs-1.1 or jaxrs-2.0 feature; for example:

The product scans all classes in the web application for JAX-RS and Swagger annotations, searching for classes with @Path, @Api, and @SwaggerDefinition annotations. The apiDiscovery-1.0 feature automatically generates a corresponding Swagger document and makes it available at the following URIs: http://host:port/context-root/swagger.json and http://host:port/context-root/swagger.yaml.

For example, if the following JAX-RS resource is deployed on the server:

Oracle SOA Suite Performance Monitoring

2017-08-31T15:22:00.001+03:00

Oracle Enterprise Manager Fusion Middleware Control Console (EM) - ensures runtime governance through composite application modelling and monitoring as well as comprehensive Service and infrastructure management functionality to help organizations maximize the return on investment. Let's consider capabilities for performance management provided by this instrument.

Monitoring the performance of the Oracle SOA Suite runtime

The Request Processing tab uses three grid views to present performance information. The tab is available under the Monitoring -> Request Processing item of the context menu SOA -> soa-infra. The displayed information is layered by:

service engine (BPEL, BPMN, Mediator, Human Workflow, Business Rule, Spring):
- average request processing time - synchronous
- average request processing time - asynchronous
- active request count
- processed requst count
- fault count
the summary about service infrastructure:
- average request processing time - synchronous
- average request processing time - asynchronous
- active request count
- processed request count
- fault count
binding components:
- web-service (WS) inbound
- web-service (WS) outbound
- Java EE Connector Architecture (J2CA) inbound
- Java EE Connector Architecture (J2CA) outbound
The following metrics are available:
- average request processing time
- processed request count
- error count

Oracle WebLogic Cluster Causes Network Storm When a Problem Happens

2017-08-23T18:17:00.000+03:00

Not every system administrator is aware of such WebLogic Server capability as Message Forwarding to Domain Logs. In addition to writing messages to the server log file, each server instance forwards a subset of its messages to a domain-wide log file. This domain-wide log file certainly helps to the system administrator understand the situation on a large domain, for instance, when several dozen servers belong to the domain, it is very helpful having all server logs sit in one place. But the convenience comes at a price.

If there are some problems caused by applications deployed on the server, the server log tends to get stuck by diagnostic messages and large stack traces. The problem is these messages and traces are being written not only to the server log file but also being forwarded to the administration server via the network and causes network storm. The administration server, as a result, might become inaccessible.

For a medium domain (4 - 8 WebLogic Server instances belong to) the idea just to disable the message forwarding capability can be considered. The Domain log broadcaster:, Severity level property value on the Environment -> Servers -> SERVER -> Logging -> General, Advanced page for every managed server must be set to Critical or higher.

How to Ensure Message Ordering on a Cluster Environment Using JCA Adapters in Oracle SOA Suite

2017-08-01T11:28:00.000+03:00

The right configuration of Oracle SOA Suite JCA-adapters for ensuring message ordering on a cluster is presented in the article.

During an integration project especially if some involved information systems are legacy, a database is often employed. Oracle SOA Suite contains a number of adapters built on the JCA technology which provides the database polling capability. The examples are the DB- and AQ-adapters.

And sometimes the order messages are processing in must be the same as the messages were generated inside a source application and, therefore were written to the database. Let me illustrate the sentence by the following: an information system creates an object, e.g. a consumer's bill. Then the object is modified and in some time deleted at all (so, the bill was generated by mistake). Obviously, the message about the object removal cannot reach the destination before the message about the creation. Otherwise, data integrity could be compromised.

Building a Real Java EE + Oracle Coherence Application with Maven

2017-07-25T11:34:00.000+03:00

There is an amazing Building a Real Application with Maven story published within a new book, Fusion Middleware Developing Applications Using Continuous Integration. The story tells of building a web-application which uses Oracle Coherence as a data store and a servlet as a data accessor. Apache Maven is used for compilation and building, the appropriate 'pom.xml' files are presented.

If we look deeply into the web-module's 'pom.xml' file, the following dependency (the gar-module) may be found:

A very interesting fact is there isn't any type declaration, so the gar-module is used as a usual 'jar' dependency. If a real application contains more gar-modules and dependencies, the best-practice for Maven users is to define the dependencies in the 'dependencyManagement' section inside the parent 'pom.xml' file. And the <type>gar</type> stanza must exist in this section since the dependency has to be used as the gar-type inside the ear-module's 'pom.xml' file.

Ok, we can say, let's define the dependencies inside the parent 'pom.xml' file and add the references on these dependencies into the 'pom.xml' files of the war- and ear-modules. Note! The 'groupId' and 'artifactId' attributes are modified.

How We Added a Spoon of Agility to a Large Oracle Service Bus Project

2017-07-12T15:28:00.000+03:00

Several months ago I already shared how to ensure guaranteed delivery for 5.000.000 messages handled per day by Oracle Service Bus (OSB). In the case, OSB is heavy used to integrate a customer relationship management application (the CRM) in a solid environment with many regional billing systems, provisioning, ERP and ordering management system (OMS), etc. Also, the integration solution is deployed across four ex-standalone corporations, each of which has its own IT infrastructure, and this circumstance makes the project more and more interesting.

The common problem from a manager's point of view is to provide consistency among services deployed on the bus, the main client application (the CRM), and numerous 3rd party applications. Also, there is a time lag in development and end up to production these parts of the infrastructure. And the development team forever must have guaranteed stable and ready to deploy code of the service bus.

The situation is usual for almost all integration projects in the World. The releases of an enterprise service bus must be delivered in a reliable way, no one integration flow (neither the client -> service bus nor the service bus -> 3rd party application communication) must fail after the release is deployed to the production environment.

Let me explain the features of our project.

A one pizza size development team, not more than 5 developers are there.
Hovewer, the team has developed and delivered 13 services and 46 adapters to a wide range of enterprise applications. The services provide very different business logic - from just wrapping a stored procedure into a SOAP-based web service till a complex orchestration employing the Splig-Join component of Oracle Service Bus.
SVN is utilized as a source code management tool.
Oracle Service Bus out of the box provides no capability for service versioning, so it's impossible to expose numerous versions of the same service simultaneously. Although the main service client, CRM application, is developed by a team working for the same company, we are able to deliver releases of the service bus regardless of this capability.
The development process is based on Agile. Sometimes it becomes a reason of inconsistent builds. In fact, this article is about how to eliminate the impact of any agile methodology on the consistency of the enterprise service bus.

The First Look at Red Hat JBoss Fuse

2017-07-03T10:00:00.000+03:00

Hello everyone!

Today I wish to share an absolutely new thing in my blog, my impressions from using Red Hat JBoss Fuse.

What exactly is Red Hat JBoss Fuse? It is a runtime environment for an implementation of Enterprise Application Integration Patterns (EIP) - Apache Camel.

There are two available forms of the runtime environment:

Apache Karaf - a production ready implementation of the OSGi standard.
Red Hat JBoss Enterprise Application Platform - a well known open source Java EE application server with commercial support. Unfortunately, Red Hat JBoss Fuse can be installed only on top of the 6.4.0 version of the application server; this version implements Java EE 6 only and this fact makes some problems discussed below.

How to Deploy Oracle SOA Suite JMS Resources on a Separate Cluster

2017-06-29T15:11:00.004+03:00

Sometimes it's strong needed to deploy JMS resources within an SOA domain, for example, to speed up the server startup, on a different non-SOA cluster. Today I wish to share a short article to explain how to do it.

The starting point is the following set of WebLogic instances: AdminServer, two SOA servers combined in the soa_cluster, and two JMS servers combined in the jms_cluster as well.

In order to demonstrate the approach, a persistent store and JMS Server must be created on every member of the jms_cluster. Our JMS resources will be hosted here.

A JMS Module, which will contain JMS resource definitions, must be created and targeted to the entire jms_cluster. A subdeployment for resource targeting management has to be defined for the module.

Let's define a uniform distributed queue as well as a connection factory inside the module.

The truth is Oracle SOA Suite isn't able to look up any JNDI name defined on another cluster, so the defined before JMS resources aren't available for soa_server1 and soa_server2. The solution is to define a foreign server on the soa_cluster. This server will open access to the JNDI tree of the jms_cluster.

The foreign server must be defined within a JMS Module targeted to the soa_cluster. A connection string to the jms_cluster (t3://server1-host:server1-port,server2-host:server2-port,etc) has to be assigned as the value of the JNDI Connection URL parameter.

The foreign server must contain a pointer on the defined before JMS queue as well as connection factory.

Composite application developers should pick up in JDeveloper a queue, created on the JMS servers JMSServer_1 and JMSServer_2, as they did before. Since the adapter definition file ...JMSAdapter_jms.jca contains only the JNDI name of the queue, and the Local JNDI Name of the defined Foreign Destination is exactly the same as the Remote JNDI Name, developed composite applications still work fine.

In order to get access to the JNDI tree of a different cluster, any composite application must use the defined before connection factory exposed via the foreign server. So, the default JNDI name for the JMS Connection must be replaced.

The JMS JCA adapter, deployed on the SOA cluster, must contain an outbound connection pool with the same name as specified for the JMS Connection in the composite application.

And the JNDI name of the defined before connection factory must be assigned as the value of its ConnectionFactoryLocation attribute.

The testing composite application should be deployed on the SOA Suite cluster. If anyone touches the application, a test instance will be created and successfully executed. A new JMS message will appear in a queue instance of the uniform distributed queue. If send kill -9 to a member of the jms_cluster, messages arrive to another half of the queue.

Well, as we have seen, the SOA Suite domain can be broken into two different parts: processing and message store. If your SOA Suite cluster takes too much time to start, this approach may be considered and implemented.

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Oracle BPM Suite 12.2.1.2 Quick Start: Installation, Configuration, BPMN 2.0 Business Process Deployment and Testing

2017-06-19T14:39:00.001+03:00

Oracle BPM Suite - a solution from Oracle for Enterprise Business Processes modeling with leveraging the BPMN 2.0 notation. Integrated development environment - JDeveloper is used for the modeling process. Oracle provides a special distributive of the solution for developers - Quick Start - which contains the Oracle WebLogic application server, BPM Suite, and JDeveloper.

This article highlights how to download Oracle BPM Suite 12.2.1.2 Quick Start from the edelivery.oracle.com web-site, install that on a developer's PC, create the first business process using JDeveloper, configure the integrated WebLogic domain (BPM Suite, SOA Suite, and Oracle Service Bus are included, and Apache Derby is here for database management), deploy the business process on this domain and start a test instance of the process.

DVM Validation on a SOA Suite Domain Causes High CPU Utilization: Analysis and Solution

2017-06-09T18:06:00.000+03:00

Problem statement

Once upon a time, my colleagues asked me an interesting question. After each update of the MDS on a large production environment, a significant performance degradation is observed. CPU load on the SOA Suite servers is increased, respectively.

The system automated leveraging Oracle SOA Suite makes extensive use of Domain Value Maps (DVM), which is intended to map from one vocabulary used in a given domain to another vocabulary used in a different domain. For example, one domain may represent Russian rubles as 'RUR', while another domain may represent those as '810' (see ISO 4217). Business users can edit DVMs at runtime using Oracle SOA Composer.

And while DVMs are not so large everything works fine, but if there are some large DVM files (> 200-300 KB), the above strange behaviour may be observed.

Let's have a look at the thread dump collected during the observation.

"[ACTIVE] ExecuteThread: '57' for queue: 'weblogic.kernel.Default (self-tuning)'" #159 daemon prio=9 os_prio=2 tid=0x0000000066bbd800 nid=0x28ac runnable [0x0000000079188000]
java.lang.Thread.State: RUNNABLE
at oracle.xml.xpath.XPathChildAxis.getNodeList(XPathAxis.java:600)
at oracle.xml.xpath.XPathStep.evaluate(XPathStep.java:1102)
at oracle.xml.xpath.PathExpr.evaluate(PathExpr.java:808)
at oracle.xml.xpath.ComparisonExpr.evaluate(XSLExpr.java:1743)
at oracle.xml.xpath.XSLExprBase.testBooleanExpr(XSLExprBase.java:514)
at oracle.xml.xpath.AndExpr.evaluate(XSLExpr.java:524)
at oracle.xml.xpath.XSLExprBase.testBooleanExpr(XSLExprBase.java:514)
at oracle.xml.xpath.AndExpr.evaluate(XSLExpr.java:524)
at oracle.xml.xpath.XSLExprBase.testBooleanExpr(XSLExprBase.java:514)
at oracle.xml.xpath.AndExpr.evaluate(XSLExpr.java:524)
at oracle.xml.xpath.XPathPredicate.filter(XPathPredicate.java:349)
at oracle.xml.xpath.XPathChildAxis.getNodeList(XPathAxis.java:627)
at oracle.xml.xpath.XPathStep.evaluate(XPathStep.java:1102)
at oracle.xml.xpath.PathExpr.evaluate(PathExpr.java:808)
at oracle.xml.parser.v2.XMLNode.selectNodes(XMLNode.java:2762)
at oracle.xml.parser.v2.XMLNode.selectNodes(XMLNode.java:2722)
at oracle.tip.dvm.sdk.util.XMLUtil.isDVMDocumentValid(XMLUtil.java:211)
at oracle.tip.dvm.entity.DVMRTObject.validateDVM(DVMRTObject.java:202)
at oracle.tip.dvm.entity.DVMRTObject.(DVMRTObject.java:130)
at oracle.tip.dvm.DVMManagerImpl.getDVMRTObject(DVMManagerImpl.java:217)
at oracle.tip.dvm.DVMManagerImpl.lookupValue(DVMManagerImpl.java:133)
at oracle.tip.dvm.LookupValue.lookupValue(LookupValue.java:95)
at oracle.tip.dvm.LookupValue.lookupValue(LookupValue.java:252)
at sun.reflect.GeneratedMethodAccessor1815.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at oracle.xml.xpath.XSLExtFunctions.callStaticMethod(XSLExtFunctions.java:115)
at oracle.xml.xpath.XPathExtFunction.evaluateMethod(XPathExtFunction.java:422)
at oracle.xml.xpath.XPathExtFunction.evaluate(XPathExtFunction.java:347)
at oracle.xml.xslt.XSLValueOf.processAction(XSLValueOf.java:152)
at oracle.xml.xslt.XSLNode.processChildren(XSLNode.java:559)
at oracle.xml.xslt.XSLTemplate.processAction(XSLTemplate.java:278)
at oracle.xml.xslt.XSLStylesheet.execute(XSLStylesheet.java:706)
at oracle.xml.xslt.XSLStylesheet.execute(XSLStylesheet.java:665)
at oracle.xml.xslt.XSLProcessor.processXSL(XSLProcessor.java:401)
at oracle.xml.jaxp.JXTransformer.transform(JXTransformer.java:578)
at ...

About Service Oriented Architecture on an Enterprise

2017-04-21T13:18:00.003+03:00

In my opinion, one of the main, if not most important, goals of SOA deployment on an Enterprise is to let to the Enterprise's information systems the ability to make continues improvement and to align technology and business via the application of service-orientation. Ideally, the systems have to be maintained by the IT division of the Enterprise, not by the developers, it's not a normal situation when a new application can be connected to the Enterprise's IT landscape only by a set of consultants who work for the developer of the deployed SOA solution.

The following four conditions may ensure the achievement of stated goals:

Asynchronous Web Services with Oracle SOA Suite

2017-03-28T14:04:00.000+03:00

The top web services based approaches for asynchronous interactions among enterprise applications are described in the article. The common used during Oracle SOA Suite leveraging method that based on a callback service and the WS-Addressing specification is shown. A number of examples of asynchronous web service creation and client generation using the JDeveloper IDE are considered.

Introduction

Time to time, when we as architects integrate some enterprise applications, asynchronous communication has to be taken into account. Asynchronous communication means a service consumer isn't blocked for a response from a service provider, it just gets an acknowledge and continue doing its work. There are two popular approaches to implementing asynchronous communication among web services:

polling refers to actively sampling the status of a being processed request by a service consumer as a synchronous activity.
callback refers to a method provided by a service consumer. When the service provider have accomplished the operation processing, it calls the consumer. In this approach, the service consumer simultaneously works like a callback methods service provider as well.

Oracle SOA Suite supports the second approach. An implemented leveraging the suite service, returns a 202 Accepted HTTP response on each request from a consumer. This response means the request is accepted and the service is going to handle it. A new instance of the composite application is created. The instance can be in the Running state during a very long time, it is usual even some human reactions are involved in the process. A callback method provided by the service consumer is invoked at the end of the process.

Message transformation in Oracle Service Bus using XSLT and XQuery

2016-10-17T10:00:00.000+03:00

You can only feel the main power of Oracle Service Bus by leveraging its message transformation capability. Today we will have a look at this capability and how to configure an XML-to-XML mapping based on XSLT or XQuery. Let's upgrade the example described within the previous entry.

Using Dynamic Routing in Oracle Service Bus

2016-09-14T13:00:00.000+03:00

Oracle's flagship Enteprise Service Bus - Oracle Service Bus (OSB) - is based on the following conceptions:

Business Service wires a service provider to the bus
Proxy Service wires a service consumer to the bus
Message Flow connects a ProxyService to a single or multiple business services. Some message flows may be very complicated and contain routing, transformation, parallel execution and other actions. Physically a message flow is specified inside a proxy service.

Let's learn how to configure the Dynamic Routing action. Dynamic routing is a kind of the Content-based Routing pattern, which is used when the BusinessService endpoint is required to be determined at run time, an alternative to Static Routing, which is used when the BusinessService endpoint is established during design time.

Why Co-location Does Matter to Gain High-Performance Java EE

2016-08-18T12:31:00.002+03:00

Introduction

Various types of JDBC drivers are implemented by various coders, it means the JDBC specification designed by the JCP team only defines the various interfaces, referenced as JDBC API, but each coder/implementer can implement these interfaces in their own ways.

Based on the ways, we can classify the implementations into four types.

JDBC Driver - Type 1 (JDBC ODBC Bridge)

This is an approach wherein the implemented class in Java makes calls to the code written in Microsoft languages (native), which speaks directly to the database.
JDBC Driver - Type 2 (Part Native Driver)

This is an approach wherein the implemented class in Java makes calls to the code written by the database provider (native), which speaks directly to the database.
JDBC Driver - Type 3

This is an approach wherein the implemented class in Java makes calls to the code written from application server providers, which speaks directly to the database. More exploration on the way the Java Driver interacts with the Middleware is required here. This kind of driver is extremely flexible since it requires no code installed on the client and a single driver can actually provide access to multiple databases.
JDBC Driver - Type 4 (Thin Driver)

This is an approach wherein the implemented by the database provider class in Java speaks directly to the database. In other words, it is a pure Java library that translates a JDBC request directly to a Database specific protocol.

The most used in the distributed world is the JDBC Type 4 driver, but in the z Systems world - the different point is. The purpose of the article is to show how significant the performance of a Java EE application can be improved just by enabling the right JDBC driver.

WebSphere Liberty Profile 9 for z/OS: Java EE 7 on the Big Iron - up to 141 Processors and 10 TB of Memory

2016-07-20T18:03:00.000+03:00

Abstract

In the article, I wish to tell you how to implement all Java EE 7 capabilities on the Big Iron, IBM Mainframes and WebSphere Liberty Profile work together providing up to 141 5 GHz processors an 10 TB of the main memory for your Java EE based applications.

Contract-First Service Design Leveraging Oracle SOA Suite and the Spring Framework

2016-07-11T16:56:00.000+03:00

Hello, my dear guests. In this post I would like to show how create a web-service basing on his contract. Oracle SOA Suite and Spring Framework are chosen as a service technological platform.

Service contract design

The first step for every solution implementation is just right describe the problem. For the demonstration, let's choose an easy task, a well-known four arithmetic operation calculator. This case is very well because it lets us show how to provide as syntax (only natural number can be assigned) as well semantic (the division by zero exception) data validation and verification.