Dariusz on Software Quality & Performance

27/05/2010

Commons logging configuration under WebSphere

Filed under: en — Tags: , — dariusz.cieslak @

Sometimes you want to customize logging level for given package in your application (to see tracing details for example). If you're using commons-logging library the configuration file is called "commons-logging.properties" and it should be places somewhere on classpath.

org.apache.commons.logging.Log=org.apache.commons.logging.impl.SimpleLog
priority=1

Then we can configure SimpleLog back-end just declared in simplelog.properties:

org.apache.commons.logging.simplelog.defaultlog=warn
org.apache.commons.logging.simplelog.log.com.mycompany.package=debug

You place those two files on classpath, redeploy application and … NOTHING HAPPENS. Those files aren't visible!

(more…)

19/05/2010

Custom CacheProvider for Hibernate based on Websphere DistributedMap

Filed under: en — Tags: , , — dariusz.cieslak @

Hibernate is a library that maps database tables to Java objects. Is performance problems arise it's very easy to add database caching for application using Hibernate (just few options in config file). Hibernate is shipped with EHCache, default cache implementation. It works well and is easy to setup.

Sometimes you have to use another caching library that has no direct support for Hibernate. Here the Hibernate API comes into play. I'll show you how to plug Websphere's DistributedMap into Hibernate.

(more…)

29/04/2010

Websphere Extreme Scale + Hibernate = ?

Filed under: en — Tags: , , — dariusz.cieslak @

Recently I was asked to integrate WXS (Websphere Extreme Scale, commercial cache implementation from IBM) into existing WPS (Websphere Process Server)-based project to implement read-only non-distributed cache (one independent cache instance per JVM). The idea is to plug cache implementation using 2nd level cache interfaces defined by Hibernate.

I plugged in the objectgrid.jar into hibernate configuration:

<property name="cache.provider_class">
com.ibm.websphere.objectgrid.hibernate.cache.ObjectGridHibernateCacheProvider
</property>

(more…)

22/04/2010

Recreate Derby Database Under WebSphere

Filed under: en — Tags: , , , — dariusz.cieslak @

WebSphere uses SQL databases for internal managment of MQ queues (Derby database engine under the covers). Sometimes you need to reset their state. Here's the script that erase and recreate BPEDB database state (tested under WS 6.1.2):

rm -rf $WID_HOME/pf/wps/databases/BPEDB
echo "CONNECT 'jdbc:derby:$WID_HOME/pf/wps/databases/BPEDB;create=true' AS BPEDB;"|\
    $WID_HOME/runtimes/bi_v61/derby/bin/embedded/ij.sh /dev/stdin

26/11/2009

Eclipse hangs – solved!

Filed under: en — Tags: , , — dariusz.cieslak @

Sometimes you see that Eclipse stops responding and causes 100% of CPU usage (UI controls not redrawn). The only action can be taken then is to kill eclipse process.

I discovered that it's caused by big console output option. Test suite with low level (DEBUG) messages are able to kill Eclipse IDE, after setting log level to WARN no such problems are present.

You can also disable Limiting console output. It helped when no verbosity could be changed by logging configuration.

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eclipse

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