Ad-hock diagnostic tools for JVM

There are bunch of graphical tools helping you to look inside of running JVM (VisualVm and JConsole are extremely helpful). Unfortunately, some times (almost always in my case), you may find yourself in SSH console on headless server side by side with your JVM (more...)

Don’t persist UIComponent state, now with attributes!

In this blogpost I showed how to disable the persistence of a UIComponent, but it was needed to write Java code to check for the specific component and change. In this blog entry I will show a more generic way to do this, with the attribute tag.

On the showDetailItem (more...)

Don’t persist UIComponent state in the session


Our use case was as followed: In our WebCenter Portal application we have a tableform layout, with a panelAccordion on the form layout. For other functionality we needed MDS persistence to be on, so we couldn’t disable MDS customizations. A side effect was that the panelAccordion remembered the showDetailItem that (more...)

Building a simple java client for forecast.io

I like to be outdoors when life allows so weather is always an interest for me. So i was very pleases to see forecast.io becoming available with global coverage after being jealous of the US only "DarkSkys" app. It was also nice to see that there is a nice (more...)

About Java class, HTTP POST and viewContentURL

As of PeopleTools 8.52 it is possible to use REST services for POST/GET functionality. However what do you do if you are on an older PeopleTools version, but still need to make a HTTP POST and then GET the response?

Continue reading

Changing the heap size of Enterprise Manager 12c

Enterprise Manager 12c is a product that is being deployed a lot lately, a vast improvement over previews version. For most DBA’s it is a tool they use regularly on a daily basis so performance is key. Fortunately oracle provides us with some documentation on how to size the repository database and heap size of the Oracle Management Service. An excellent white paper on EM12c sizing can be found here on OTN:

http://www.oracle.com/technetwork/oem/framework-infra/em12c-sizing-1590739.pdf

Interestingly enough it states that Oracle considers installation with +1000 targets as a medium sized em12c environment. That limit of +1000 targets is reached (more...)

Netbeans 7.3 Available

Uncategorized
| Feb 25, 2013
Are you a netbeanie?

Using UriTemplate to change path parameters in a URI

I have been recently working on a client generator in the wadl.java.net project and I was solving a bug where I wanted to change path parameter on a URI. This turned out to be quite easy with existing classes that are part of the Jersey project.

First of (more...)

Introduction to Collated Views with Couchbase 2.0

Most of the applications have to deal with "master/detail" type of data: breweries and beer department and employees invoices and items  ... This is necessary for example to create application view like the following: With Couchbase, and many of the document oriented databases you have different ways to deal with this, (more...)

Is your WebLogic Server slooow? Might be because of low entropy

On Linux low entropy can cause certain operations to be very slow.

SSL operations need entropy to ensure randomness. Entropy is generated by the OS when you use the keyboard, the mouse or the disk.

If an SSL operation is missing entropy it will wait until enough is generated.

If (more...)

How to simulate Coherence node failure in JUnit test

Recently, I was working on renewed version of Coherence data loss listener. New version provides simple utility to attach partition loader to any cache. Such partition loader is guaranteed to be called for every partition of newly created cache or after partition has been lost. Unlike CacheStore, partition loader (more...)

Remote code execution in Java made trivial

SSH offers a very convenient way to execute shell scripts remotely. Code like

ssh myserver.acme.com << EOC
cd $APP_HOME
./start_my_stuff.sh
EOC

are fairly easy to write and read.

But while remote execution itself is easy, writing actual distributed code is total mess.

I’m a Java guy. I (more...)

Couchbase 101: Create views (MapReduce) from your Java application

When you are developing a new applications with Couchbase 2.0, you sometimes need to create view dynamically from your code. For example you may need this when you are installing your application, writing some test, or you can also use that when you are building frameworks, and wants to (more...)

Making Eclipse IDE Supports JSF 2.0

Uncategorized
| Oct 22, 2012

Autocomplete was not working for JSF tags in my Eclipse. I googled it and finally found the solution on http://www.mkyong.com/jsf2/how-to-make-eclipse-ide-supports-jsf-2-0/

Thanx Mkyong.

The different thing I did is; I downloaded javax.faces-2.xx.xx.jar and saved in a specific folder. Then I created a user library with this jar. I did not use “jsf-api-xxx.jar and jsf-impl-xxx.jar“.


Missing IPV6 address for local network interfaces causes service timeout

Year ago I installed Weblogic server + Oralce database server for a customer. Few months later my colleagues asked me whether something has changed in the environment or if something happened at the data center, because they started to see Java exceptions for unknown hostname for a web service they were calling and this was happening only from time to time. We’ve checked the firewall rules, DNS and all the stuff, but everything seemed to be working fine. The only solution by that time they came out was to add the hostname to the hosts file of the Weblogic server. (more...)

Safepoints in HotSpot JVM

Term Stop-the-World pause is usually associated with garbage collection. Indeed GC is a major contributor to STW pauses, but not the only one.

Safepoints

In HotSpot JVM Stop-the-World pause mechanism is called safepoint. During safepoint all threads running java code are suspended. Threads running native code may continue to run (more...)

Separate docs for MySQL Connectors

The MySQL documentation section has always had this Topic Guides page containing links to the docs for the various MySQL Connectors -- the official database drivers for various languages and programming technologies. That is the most convenient way to get the information for each Connector in PDF form, rather than downloading the entire Ref Man PDF. For HTML, it was more of a shortcut, because

Generating an EJB SDO Service Interface for Oracle SOA Suite

In Oracle SOA Suite you can use the EJB adapter as a reference or service in your composite applications. The EJB adapter has a flexible binding integration, there are 3 ways for integrating the remote interface with your composite.

First you have the java interface way which I described here (more...)

Using JDeveloper Maven integration to run Oracle ADF sample in Java cloud

Readers of this blog might already took a notice about one link on a right side, pointing to experimental page with live ADF sample application embedded on it. It looks like I'm not alone to have the idea of live ADF samples in my head. Zeeshan Baig, featured in recent (more...)

Consultancy

I have a permanent job at the NetCracker‘s System Performance group. Recently I was offered to do one day job outside, on-site in another company, which coincidentally has an office close to NetCracker’s Moscow office. It was an opportunity to apply my skills in a completely different situation which I couldn’t miss; plus I’ve never done public presentations before and this was a good occasion to practice that. Here I’d like to write down some notes how the event went.

2 or 3 weeks before the event I’ve got the list of topics to work on. It included several (more...)