A JBoss Project
Red Hat

Kosmos Reference Manual

Komposite Open Source Monitoring Suite

For the Kosmos 0.2.x branch
Revision: $Id$
Midori Consulting (http://www.midori.hu)

Aron Gombas

<aron dot gombas at midori dot hu>
Copyright © 2005 Aron Gombas


Preface

Project motivation & history

Working as developer and later lead engineer on various Java and C++ projects in the recent years, I had to spend a serious amount of time reguarly checking various sources of information: build reports, source code metrics, PMD and CheckStyle reports, the source code itself, project pages of the dependencies, industry news in online mags and such. In other words, I had to filter and manage information coming from different places to get a global picture about the current state of the project. This process was extremely cumbersome and time-consuming, and distracted me from the more enjoyable part of engineering.

Other members of the team suffered from the same problem, however they wanted to have this global 24/7 picture from a slightly different aspect, based on their "roles" in the team. We clearly needed some flexible and easily personalizable solution.

And this is what portals are about, right? Aggregation and customization.

Later I came up with the idea of developing a suite of lightweight, highly customizable portlets backed by a central server mechanism, and then deploying those to a customization-enabled portlet container. This way beside having a "reference" community page, everyone could set-up his own personal portal page.

This was how Kosmos has born.

While working on the very first portlets, I contacted JBoss and had explained them my plans. They liked the idea, it was in sync with certain things what they wanted to do themselves, so they invited my project as one of the first projects hosted in their new-born JBoss Labs forge.

 

Figure 1. Kosmos logo

In the very beginning, the project ran under a different temporary codename, but when incubating it to JBoss Labs, I had to find out the final name. As the guys at JBoss were waiting for me, I had to come up with a fancy name in a couple of hours. I decided to use the word kosmos, because of several reasons:

  • is there anything more beautyful than our universe?
  • the cosmos flower is a real beauty with its simplicity
  • "mikrokozmosz" is a wonderful musical piece by Bela Bartok, one of the greatest Hungarian composers
  • gives the opportunity to play more with the notions related, like "kosmonaut"
  • a name with the length of six characters perfectly fits Java package names, jar filenames and such

Acknowledgments

Huge thanks to my wife, Szilva, for not giving up the struggle for such a long time, and Damon Sicore and everyone else at JBoss Labs for their support. Special thanks to every Kosmos project contributor (you know, guys, who you are).

Contact

You can always find the latest information about the Kosmos project, published by the community, at the JBoss Labs project page: http://labs.jboss.com/projects/kosmos. Beside the downloads and documentation, we host also our Wiki and blog here, and this is our primary information resource. Come and visit us regularly.

You can reach me in email at the following address: .

Aron Gombas

Chapter 1. Overview

Vision

The first releases of Kosmos focuses on integrating a small set of de-facto standard open source tools like Subversion or CruiseControl. These releases will form the base for future development and aspire to reach a production-ready state as soon as possible.

In the long run, we have left the door open with an extensible architecture. We will consider supporting anything demanded. That includes both popular open source and commercial tools if they are accessible through some kind of public web-service, API, or at by page-scraping (in case of web interfaces).

Design goals

We aim to reach the following primary design goals:

  1. Lightweight architecture implemented with POJOs.

  2. Several independent and simplistic components rather than single monolithic one.

  3. Easy and flexible deployment, and so no changes in the monitored resources.

  4. Full transparency for the monitored resources and no extra burden on them.

  5. Maximum vendor-indepence: no proprietary features of servlet containers, application servers, portlet containers or WebDAV servers.

  6. Consistent and intuitive user interface for all portlets.

  7. Visualization by using charts and graphics instead of plain textual information, wherever possible.

Implementation goals

We aim to reach the following primary implementation goals:

  1. Java 1.5 language compatibility (some of the language features introduced in Java 1.5 are not compatible with Hessian).

  2. Portlets that are perfectly JSR-168-compliant.

  3. Portlets that are conform with the portal theme by using exclusively the standard JSR-168 CSS styles.

Dependencies

Kosmos is built on the top of:

  • Apache Commons projects: various packages used as utility classes.

  • Display tag library: used for rendering the tables.

  • Hessian binary web service protocol: used for implementing the web-services.

  • JavaSVN Subversion client library: used for processing Subversion repositories.

  • Jakarta Slide: its client library is used to access the WebDAV-based cache. Additionally, Slide is also our primary WebDAV server implementation.

  • JFreeChart library: used to generate the chart images.

  • JTidy: used to transform the HTML documents to XML before further processing.

  • JSTL tag library: used in the view tier.

  • Log4j library: used for general-purpose logging.

  • Saxon XSLT and XQuery processor: used to analyze HTML documents.

  • Spring Framework: used as IoC container and AOP implementation.

Compatibility

Please see the detailed compatibility matrix on the project website.

Chapter 2. Components and features

Kosmos server

The “remote server” component acts like a traditional back-end: it collects, analyzes, stores and caches all the information. It then provides results for the front-end. You might ask, "Is it necessary to complicate the deployment with this additional component?" Having a single layer (portlets only, that access the monitored resources directly), it could be much simpler!

The primary reason is that certain operations performed by the system (like monitoring a remote Subversion repository) can be very expensive: traversing the repository content can easily take hours, depending on many factors like the repository complexity, server performance, or network bandwidth. By using a simple caching mechanism built into the server component, if several portlet instances are monitoring the same repository and they fire identical requests, only the very first will result in a new traversal! The other requests will receive the cached result until the first cache-miss (which can be caused also by a time-out, of course). This simple mechanism gives a huge performance boost and puts less burden on the “target box”, the Subversion server in this case.

Server component features:

  • Implements the application logic.

  • Provides Hessian-based web services for the portlets (view tier).

  • Caches service calculation results transparently.

  • Stores the generated static content (e.g. chart images) to pluggable storage mechanisms (to a WebDAV repository by default).

Kosmos portlets

The portlets implement the “view tier”, they are responsible for rendering the results computed by the server component. Portlet technology was chosen over “traditional” web-application techniques, because flexible customization was a high-priority project goal.

You can set up any portal page, which can contain any number of the portlets in various layouts. Also, you can mix Kosmos portlets with portlets coming from other projects or vendors, without any restriction. The deployment and configuration process is portlet container-dependent, thus it is out of the scope of this document. Please refer to the technical documentation of your particular container.

Using the portlet user interfaces should be straight-forward. There are a set of common features supported by all the portlets:

  • You can minimize, maximize each portlet or get some help by clicking the icons in the titlebar (provided your portlet container supports this and your portal theme doesn't hide those controls).

  • You can sort the items in the tables in ascending or descending order by clicking to the column headers.

  • You can get detailed information related to a given attribute by clicking the information icons.

  • You can zoom and unzoom chart images by clicking them.

CruiseControl Monitoring portlet

This portlet monitors the continuous integration build processes managed by CruiseControl, a very well-known continuous build framework. It helps you to track whether the builds of your projects break, without checking email, reports, or web reports.

Portlet features:

  • It reports on the build labels, build results, timestamps, and unit test results. You can also get detailed information about the unit tests.

  • The status icons denote failed builds or successful builds with failed unit tests.

Please visit http://cruisecontrol.sourceforge.net if you want to learn more about CruiseControl.

JIRA Monitoring portlet

This portlet monitors projects hosted by JIRA, a popular issue tracking and project management application. It helps you by giving a quick overview about the state of several projects in a single place.

Please note that Kosmos provides two different service implementations to serve data for this portlet. You can choose between these two implementations simply by specifying different service.url parameters for the portlet:

  1. http://localhost:8080/kosmos-server/kosmos-services/jira-service: the data will be served by a service that downloads JIRA webpages and analyzes their HTML content.
  2. http://localhost:8080/kosmos-server/kosmos-services/jirasoap-service: the data will be served by a service that uses the JIRA SOAP remote API to download information directly from the JIRA web application. Please note that you have to enable the SOAP interface in the JIRA settings, in this case.

Portlet features:

  • It reports on project details and issues organized by status, priority and assignee. Some of the statistics are available as graphical charts.

  • The status icons denote projects with a significant number of open issues.

  • You can jump onto the JIRA page of the given project by clicking the project name, or to the actual project webpage by clicking the URL in project details view.

Please visit http://www.atlassian.com/software/jira for a short summary about JIRA.

SourceForge Monitoring portlet

This portlet monitors the file releases on SourceForge, the world's largest development and download repository of open source projects. The main goal of this portlet is to help you to keep your project dependencies and development toolbox up-to-date, without regularly checking the dependency project pages one-by-one.

Portlet features:

  • It reports on the latest versions of the packages and their age.

  • The status icons denote new releases (projects with fresh file releases) or inactive projects (projects with very old latest release).

  • You can jump onto the download pages of the given project or that particular version on SourceForge by clicking the appropriate package name or the version label.

Please visit the main page of Sourceforge at http://www.sourceforge.net if you haven't done it before.

Subversion Monitoring portlet

This portlet monitors repositories managed by Subversion, one of the most widely used version control systems. It helps you track the activity and complexity of several separate repositories very easily in a single portlet.

Portlet features:

  • It can connect both to secure and public repositories.

  • It reports on the latest touch, developer activity and repository statistics. Additionally, some of stats are visualized in charts if you click to the information icons.

  • The status icons denote inactive repositories (repositories with very low activity or very old latest touch).

Please visit http://subversion.tigris.org if you are interested in Subversion.

Good practices

Here are a couple of additional ideas which can make your life easier when configuring your particular Kosmos portal instance:

  • Combining Kosmos portlets with other portlets is a good practice to maximize the information effectively aggregated on your portal page. Other than the standard Kosmos portlets, you should consider using: Forums portlet, RSS portlet, Blog portlet, Poll portlet, CMS portlet and Wiki portlet.

    PortletBridge is another extremely useful open source component, don't miss it.

    All these (provided you use them in the right way) should improve the communication both inside your community and with the external world.

  • All portlets support multiple monitored resources, and you can group them as you wish. For example, you can have a separate portlet for monitoring Spring, and another for monitoring ACEGI. It might make sense to group those as related packages together within a single portlet, and keep all the Struts-related packages in another portlet, and Tomcat-related packages in a third one.

Chapter 3. Deployment and configuration

Requirements

You will need to deploy the server component and the portlets separately. Please note that however we listed recommended container implementations below, you can use any other product until that is compliant with the appropriate servlet or portlet specifications. You can learn more about the compatibity issues by studying the compatibility matrix maintained on the project website.

  • We offer deployment scripts in form of Ant build scripts, which automate the deployment process. If you want to use these, you will need to install Ant. The default target of each script is redeploy, which deletes the old deployment (if there exists) and deploys a new clean one. Of course, you can still deploy manually if Ant is not available in your environment. In any case, it's a good idea to look through the deploy scripts.

  • The server component requires standard servlet containers (or a single container) for proper running. The most trivial option is to use the Apache Tomcat container.

  • The portlets needs a JSR-168-compliant portlet container. One possible open source choice is JBoss Portal deployed into a JBoss Application server instance.

  • For storing the dynamically generated content (e.g. chart images), you need a WebDAV server implementation. One option is to use Jakarta Slide, but Subversion provides a WebDAV interface, too.

Deployment models

Due to the flexible architecture of Kosmos, it's possible to deploy the system to various environments, for example:

  • minimalistic: a single container which can act both as servlet-container for Kosmos server, the WebDAV server, and the portlet-container for the portlets. As result, there will be three separate web applications running in the same container. This is the simplest way to deploy Kosmos and it can be an effective setup in many cases.

  • advanced: separate (even heterogenous!) containers on the same physical node of the network: for example you can use Apache Tomcat as servlet-container and JBoss AS with JBoss Portal as portlet-container. It means that your components will run in separate JVMs which can be useful from a stability or security viewpoint.

  • distributed: containers on separate nodes. Server A can run one instance of JBoss AS to host the server component, server B can run another to host the WebDAV repository, while server C can run a third one to host the portlet container.

    For advanced users it is possible to deploy each service of the server component to different nodes if that's necessary! You can fine-tune the performance of the system this way.

    Since all the information is exposed as standard Hessian web-services, it is possible and perfectly legal to develop other types of front-end for the system: web applications, applets or desktop applications and completely avoid using a portlet container!

Figure 3.1. Minimalistic deployment

You can complicate all the models by another important decision: what RDBMS to use to support the portlet container and how to deploy it. Again, it's possible to use the same physical node or nodes which host the containers, or to have separate database servers for this purporse. It's all up to you, your needs and possibilities.

In the following sections, we give detailed step-by-step instructions for various deployment models, but because of their huge variety, we will cover just some of those. After reading these, it should be relatively easy to find out what to do in situations not listed here.

Deployment step-by-step for Apache Tomcat and eXo Platform

  1. Install eXo Platform as written in its documentation. We recommend using the bundle distribution, because that contains both the Apache Tomcat servlet container and the eXo Platform portlet container in a single package.

  2. Deploy Jakarta Slide to the Tomcat instance used by eXo as written in the JBoss AS step-by-step.

  3. You can deploy the server component into the Apache Tomcat instance used by eXo, by running the server deploy script:

    ant -f deploy-server-tomcat.xml

    Please don't forget to set the CATALINA_HOME environment variable before.

  4. Deploy the portlet web application by running the portlet deployment script as:

    ant -f deploy-portlet-exo.xml

  5. Launch eXo, open the default portal page (e.g. http://localhost:8080/portal), and login with the default account (admin and exo).

    Go to page edit mode and add the Kosmos portlets to the page. Change back to view mode.

Deployment step-by-step for Apache Tomcat and Gridsphere

Follow these steps:

  1. Install Gridsphere as written in its manual.

  2. Deploy Jakarta Slide to the Tomcat instance used by Gridsphere as written in the JBoss AS step-by-step.

  3. You can deploy the server component into the Apache Tomcat instance used by Gridsphere, by running the server deploy script:

    ant -f deploy-server-tomcat.xml

    Please don't forget to set the CATALINA_HOME environment variable before.

  4. Deploy the portlet web application by running the portlet deploy script as:

    ant -f deploy-portlet-gridsphere.xml

    As an additional step, copy $GRIDSPHERE_HOME/build/lib/gridsphere-ui-tags.jar to $CATALINA_HOME/webapps/kosmos-portlet.war/WEB-INF/lib.

  5. Launch Gridsphere, open the default portal page (e.g. http://localhost:8080/gridsphere), and login with the default account (root and empty password). After this, there are couple of extra steps that you can do using the Gridsphere admin portlets:

    1. Deploy kosmos-portlet manually.

    2. Create a new public group kosmos that contains all the Kosmos portlets and add your user to this new group.

    3. Go to your new page and add the Kosmos portlets to this.

Deployment step-by-step for JBoss AS and JBoss Portal

Follow these steps:

  1. Install JBoss AS as written in its manual. The current reference documentation both for JBoss AS and JBoss Portal is available from the http://www.jboss.org site.

  2. Deploy Jakarta Slide to JBoss AS and configure it as written in the appropriate manuals. We have included the Slide web application archive (slide.war) in the binary distribution package of Kosmos, under the /etc folder. In most situations, it's enough to copy this file to the deployment folder of the servlet container or the application server.

    As a quick test, check whether you can access the Slide repositories through a WebDAV navigator. If you use Windows XP, it is able to map a WebDAV repository as a folder to your filesystem. Otherwise try to open the repository in your browser using the http://localhost:8080/slide URL.

  3. Install JBoss Portal as written in its manual. Test if there are no error messages in the JBoss AS logfile.

  4. Run the server deploy script as:

    ant -f deploy-server-jboss-as.xml

  5. Deploy the portlet web application by running the portlet deploy script as:

    ant -f deploy-portlet-jboss-portal.xml

  6. Launch JBoss AS and check the default portal page (e.g. http://localhost:8080/portal), whether you can see the Kosmos page in the page list.

It is possible also to hot-deploy the components while JBoss AS is running.

Deployment step-by-step for Apache Tomcat and Liferay Portal

  1. Install Liferay Portal as written in its manual. We recommend using the bundle distribution, because that contains both the Apache Tomcat servlet container and the Liferay Portal portlet container in a single package.

  2. Deploy Jakarta Slide to the Tomcat instance used by Liferay as written in the JBoss AS step-by-step.

  3. You can deploy the server component into the Apache Tomcat instance used by Liferay, by running the server deploy script:

    ant -f deploy-server-tomcat.xml

    Don't forget to set the CATALINA_HOME environment variable before.

  4. Hot-deploy the portlets by running the portlet deploy script:

    ant -f deploy-portlet-liferay-portal.xml

    Edit this file and make sure the properties are correct. If you have CATALINA_HOME set, you shouldn't have to worry about the

    container.dir

    property. Ensure

    container.lib

    and

    liferay.home

    are correct. Hot-deploy the portlets as written at http://www.liferay.com/web/guest/documentation/development/hot_deploy. The portlet distribution package of Kosmos contains a customized version of portlet-deployer-3.5.0.xml which you might find convenient as starting point.

    There are a couple of issues you can face while starting up your Liferay, depending on your JVM version:

    1. You have to downgrade the $LIFERAY_HOME/webapps/kosmos-portlet/WEB-INF/lib/ext/commons-logging-1.0.4.jar to commons-logging-1.0.3.jar (downloadable from http://www.ibiblio.org/maven/commons-logging/jars/) if Liferay throws a java.lang.NoSuchMethodError: org.apache.log4j.Category.log(Ljava/lang/String;Lorg/apache/log4j/Level;Ljava/lang/Object;Ljava/lang/Throwable;)V. The same exception might be thrown also for the kosmos-servlet and the kosmos-portlet web-applications, the fix is the same: downgrade the same JAR also in $LIFERAY_HOME/webapps/kosmos-server/WEB-INF/lib and $LIFERAY_HOME/webapps/kosmos-portlet/WEB-INF/lib, respectively.

    2. You have to delete $LIFERAY_HOME/common/endorsed/xml-apis.jar if Liferay throws a javax.servlet.ServletException: Provider org.apache.xalan.processor.TransformerFactoryImpl not found exception

    3. You have to copy $LIFERAY_HOME/liferay/WEB-INF/tld/liferay-portlet.tld to $LIFERAY_HOME/webapps/kosmos-portlet/WEB-INF/tld if Liferay throws a org.apache.jasper.JasperException: /pages/sf_monitoring.jsp(1,1) File "/WEB-INF/tld/liferay-portlet.tld" not found or similar exception

    4. You have to copy $LIFERAY_HOME/liferay/WEB-INF/lib/util-taglib.jar to $LIFERAY_HOME/webapps/kosmos-portlet/WEB-INF/lib if Liferay throws a org.apache.jasper.JasperException: /pages/sf_monitoring.jsp(1,1) Failed to load or instantiate TagExtraInfo class: com.liferay.portlet.taglib.ActionURLTei or similar exception

  5. Launch Liferay, open the default portal page (e.g. http://localhost:8080) and login with the default account (test@liferay.com and test).

    Open the portlet administration portlet and assign some roles to the Kosmos portlets (e.g. User and Guest). Also, set the JIRA and Subversion monitoring portlets to wide style, all the others to narrow. Create a new page or go to an existing page, and check whether you can see the Kosmos portlets selectable in the combo boxes at the bottom of the portal pages.

Deployment step-by-step for Apache Tomcat and Apache Pluto

Follow these steps:

  1. Install Pluto as written in its manual. We recommend using the bundle distribution, because that contains both the Apache Tomcat servlet container and the Pluto portlet container in a single package.

  2. Deploy Jakarta Slide to the Tomcat instance used by Pluto as written in the JBoss AS step-by-step.

  3. You can deploy the server component into the Apache Tomcat instance used by Pluto, by running the server deploy script:

    ant -f deploy-server-tomcat.xml

    Please don't forget to set the CATALINA_HOME environment variable before.

  4. Pluto has a portlet called Deploy War Admin Portlet to deploy other portlets. It makes the deployment process extremely easy: just select the portlet WAR and configure the pages, Pluto will take care of all the low-level details. Don't forget to restart Pluto after you've deployed your portlets, otherwise your new portal page won't appear in the menu!

    If you decided to do an automated deployment instead of using the administrative portlet, run the portlet deploy script:

    ant -f deploy-portlet-pluto.xml

    . After this, you have to manually update the following Pluto configuration files:

    pageregistry.xml
    portletcontexts.txt
    portletentityregistry.xml

    You can use the sample files found in /conf/pluto of the Kosmos portlet distribution package as starting point.

  5. Launch Pluto and check the default portal page (e.g. http://localhost:8080/pluto/portal), whether you can see your new page in the page list.

General server configuration

The server component can be configured through its Spring application context configuration file kosmos-services-servlet.xml . (Please note that former versions were configurable partly through their web.xml, but after introducing the pluggable cache store mechanism, all configuration was moved to the Spring XML.) It's absolutely straightforward to modify it, but please note that the configuration changes might require reloading the servlet!

Here is some basic help for better understanding of the kosmos-services-servlet.xml:

  • Each service is implemented by a POJO that is exposed as web service by a Spring-based Hessian proxy class. Caching is implemented through a very simple AOP interceptor around the service POJO instance. Consequently, there is one section like this per service:

    <!-- CC service --> <bean id="ccService" class="hu.midori.kosmos.server.cc.CcServiceImpl">   <property name="store" ref="webdavStaticContentStore"/> </bean>  <bean id="ccServiceProxy" class="org.springframework.aop.framework.ProxyFactoryBean">   <property name="targetName" value="ccService"/>   <property name="interceptorNames"> 	<list> 	  <value>serviceCachePointCutAdvisor</value> 	</list>   </property> </bean>  <bean name="/cc-service" class="org.springframework.remoting.caucho.HessianServiceExporter">   <property name="service" ref="ccServiceProxy"/>   <property name="serviceInterface" value="hu.midori.kosmos.protocol.CcService"/> </bean>

    You can activate and deactivate the services by adding or deleting these sections, depending which portlets you're going to use. In the default configuration, all the services are activated and unless there is a special reason to remove them, it's better not to touch these sections. There is hardly any performance penalty or security problem even if you have unused, but active services.

    There is one required property for the services: this is called store and it's a reference to the cache store to use. See next section for more details.

  • The services can generate and save cached data, mostly images that are later used by the portlets view tier. There is a simple, but flexible store mechanism built into Kosmos. However this is a "pluggable" mechanism, by default, there is only one implementation shipped with Kosmos: a WebDAV-based cache store. (In the very beginning, using WebDAV for this purpose was a requirement, not an option, but the poor quality of the WebDAV client libraries and servers motivated adding an extra level of abstraction to ensure that with some minimal work, any other web-based store can be used here.)

    The cache stores are implemented as POJOs, too. They can have different properties depending on the implementation, we discuss only WebdavCachedDataStore here:

    <!-- WebDAV cached data store --> <bean id="webdavCachedDataStore" class="hu.midori.kosmos.server.WebdavStaticContentStore">   <property name="webdavUrl" value="http://localhost:8080/slide/files"/><!-- Both HTTP and HTTPS protocol can be used here. -->   <property name="webdavUser" value=""/>   <property name="webdavPassword" value=""/>   <!-- This URL will be used as base URL for the generated images. 	   If you don't specify anything here, the value of "webdavUrl" 	   will be used. Uncomment this, if you want to override that. 	<property name="clientUrl" value="http://myserver/my-webdav/kosmos-images"/>   --> </bean>

    The URL is required, but you can leave the user and password empty if your WebDAV is configured to serve unauthenticated requests, too. In the URL you can use both HTTP and HTTPS protocols. The clientUrl parameter makes it possible to override the URLs generated for the clients: you can store the images as https://secure.mydomain.com/mywebdav, but access them as http://public.mydomain.com/webdav if your network environment is configured to match this.

  • The trigger for the update scheduler can be configured as a standard Spring trigger bean, either a simple one or a cron-style one:

     <bean id="serviceResultUpdateTrigger" class="org.springframework.scheduling.quartz.SimpleTriggerBean">   <property name="jobDetail" ref="serviceResultUpdaterJob"/>   <property name="startDelay" value="7200000"/><!-- start and repeat in every 2 hours -->   <property name="repeatInterval" value="7200000"/> </bean> <!--   Alternatively, a cron-style trigger can be used.   For this, remove the previous bean definition and use this one:    <bean id="serviceResultUpdateTrigger" class="org.springframework.scheduling.quartz.CronTriggerBean"> 	<property name="jobDetail" ref="serviceResultUpdaterJob"/> 	<property name="cronExpression" value="0 0 6 * * ?"/>   </bean> --> 

    All the information delivered by the services will be automatically refreshed in the given time. For example, you can schedule a very expensive Subversion repository traversal at 2 o'clock in the morning every day, so the portal will reflect up-to-date results by the time you get to your browser.

    See the Spring Framework documentation: Wiring up jobs using triggers and the SchedulerFactoryBean for more examples.

  • It's possible (and relatively easy) to do more complicated changes (like using separate or even inhomogenous cache stores per service, using more than one instance of the same service, etc.), but please make sure that you know what you do. It's recommended to study the related sections of the Spring Framework documentation, too.

Please take a look at the sample configuration files shipped in the distributed package.

General portlet configuration

All the other portlet settings can be configured by specifying <init-param> entities in the portlet.xml . The common init-parameters supported by every portlet are:

monitored.resource (required)

It is used only for display purposes, does not affect the actual functionality.

service.url (required)

It points to the appropriate Hessian-service. For example, in the case of SfMonitoringPortlet it can be: http://localhost:8080/kosmos-server/sf-service.

A quick check to test whether the service is available at the given URL is opening the URL in a normal browser window. You should see a “Hessian requires POST” error message if everything is fine.

monitored.urls (required)

Comma-separated list of items to monitor. Depending on the portlet, items are used as:

  • CcMonitoringPortlet: URLs of the webpages where CruiseControl publishers produce their output including the logfiles related to the projects to monitor. For example: http://cruisecontrol.jboss.com/cc/buildresults/ejb3-4.0-testsuite,http://cruisecontrol.jboss.com/cc/buildresults/ejb3-head-testsuite.

  • JiraMonitoringPortlet: URLs of the JIRA home pages related to the projects to monitor. For example: http://jira.jboss.com/jira/browse/JBWIKI,http://jira.jboss.com/jira/browse/JBLAB.

  • JiraSoapMonitoringPortlet: list of colon-separated JIRA SOAP service URL and saved filter names related to the projects to monitor. Username and password is required for proper authentication. For example: http://soaptester:soaptester@jira.atlassian.com/rpc/soap/jirasoapservice-v2?wsdl:Fixed for unreleased versions.

  • SfMonitoringPortlet: URLs of the SourceForge pages which host the projects to monitor. For example: http://www.sourceforge.net/projects/springframework,http://sourceforge.net/projects/acegisecurity.

  • SvnMonitoringPortlet: URLs of the Subversion repositories to monitor. For example: http://svn.apache.org/repos/asf/commons,http://svn.apache.org/repos/asf/db. If you have secure repositories, you must include the username and the password in the URL: http://myusername:mypassword@www.mycompany.com/svn/mysecurerepo. Please note that the security information will not appear in the user interface, so if you restrict the access to portlet.xml and the serverside log, then it's completely safe.

fixed.view (optional)

It is possible to restrict the portlets to a certain view and to disable the item listing and the navigation between sub-views. For example, you might want the portlet to display only the commit history of a single Subversion repository. If you don't specify anything for this parameter (this is the default), then the main view will be the item list and each sub-view will be accessible from there.

Depending on the portlet, you can use one of the following self-explanatory values:

  • CcMonitoringPortlet: viewTestDetails.

  • JiraMonitoringPortlet: viewAssigneeDetails, viewIssueDetails or viewProjectDetails.

  • JiraSoapMonitoringPortlet: same like the previous one.

  • SfMonitoringPortlet: does not support fixed views.

  • SvnMonitoringPortlet: viewActivityDetails, viewCommitterDetails, viewRepositoryDetails or viewRevisionDetails.

Here is a section of the default portlet.xml file shipped in the distribution:

<portlet>   <portlet-name>KosmosDependenciesSfMonitoringPortlet</portlet-name>   <portlet-class>hu.midori.kosmos.portlet.sf.SfMonitoringPortlet</portlet-class>   <supported-locale>en</supported-locale>   <supported-locale>hu</supported-locale>   <resource-bundle>hu.midori.kosmos.portlet.sf.sf_monitoring</resource-bundle>   <init-param> 	<name>monitored.resource</name> 	<value>Kosmos Dependencies</value>   </init-param>   <init-param> 	<name>service.url</name> 	<value>http://localhost:8080/kosmos-server/kosmos-services/sf-service</value>   </init-param>   <init-param> 	<name>monitored.urls</name> 	<value> 		  http://sourceforge.net/projects/cruisecontrol/, 		  http://sourceforge.net/projects/displaytag/, 		  http://sourceforge.net/projects/jfreechart/, 		  http://sourceforge.net/projects/jtidy/, 		  http://sourceforge.net/projects/saxon/, 		  http://www.sourceforge.net/projects/springframework 	</value>   </init-param>   <supports> 	<mime-type>text/html</mime-type> 	<portlet-mode>HELP</portlet-mode> 	<portlet-mode>VIEW</portlet-mode>   </supports>   <portlet-info> 	<title>SourceForge Monitoring</title>   </portlet-info> </portlet>

If you have any problems or questions, please study the default portlet.xml , and you will probably find the answer there.

I18n

Setting the preferred language for the whole application is a two-step process:

  • For the server component, you have to set the context parameter called locale in its web.xml:

    <context-param>   <param-name>locale</param-name>   <param-value>en</param-value> </context-param>

    This setting will affect mostly the labels on the chart images, as these are the only resources generated by the server component that are language-dependent.

  • For the portlets, you have to set the context parameter which configures the JSTL library in the portlet module web.xml:

    <context-param>   <param-name>javax.servlet.jsp.jstl.fmt.locale</param-name>   <param-value>en</param-value> </context-param>

    This setting will specify the language for the whole web-based user interface.

Both these parameters accept the standard Java locale signs as value, but please make sure that the property file of the selected language is available in your distribution. Please see the project site for localized versions available.

For advanced users: as you see, one server supports only one language set, which is absolutely sufficient in most of the cases. A multi-language server would require a more complicated caching mechanism (some parts of the content are language-independent thus could be shared between client requests with different locale settings, while others are not), which is necessary only in some infrequent environments. As workaround, for two languages you can launch two separate Kosmos servers with different language settings.

Chapter 4. Developer guide

Building from source

The Kosmos build system use a small set of easy-to-understand Ant scripts and property files. There are three actual build-scripts: one for building the server component ( build-server.xml), one for building the portlets (build-portlet.xml) and one for creating the distribution packages (build-distro.xml). The two “real” build scripts use a common template build/build.xml and are configured through the property files in the build directory.

The variable names are self-explanatory and all the targets are well-documented in the appropriate script:

Buildfile: build-portlet.xml Buildfile: build-portlet.xml Kosmos Portlet Module build-script Main targets:   all       Recompiles all Java source files  clean     Cleans up temporary files created during previous builds  compile   Compiles Java source files  deploy    Deploys the module to the container  dist-bin  Prepares all binary distributables  redeploy  Redeploys the module to the container  undeploy  Undeploys the module from the container Default target: redeploy

For instance, recompiling the full source code is simply:

ant -f build-portlet.xml all

Please study the scripts themselves for further details.

Generating the distribution packages

There are a couple of Ant targets for this purpose:

Buildfile: build-distro.xml Kosmos Distro build-file Main targets:   clean               Cleans up temporary files created during previous builds  dist                Prepares all distributables  dist-bin            Prepares all binary distributables  dist-src            Prepares all source distributables  javadocs            Generates the javadocs  manual              Generates the manual in all formats  manual-html         Generates the manual in multi-page HTML format  manual-pdf          Generates the manual in PDF format  manual-single-html  Generates the manual in single-page HTML format Default target: dist

The only detail you have to care about is setting the correct local paths in build.properties for the following dependencies that are not included in the Kosmos distribution package:

docbook.dir=/java/docbook-xsl-1.69.1 fop.dir=/java/fop-0.20.5 saxon.dir=/java/saxonb-8.5

Server component architecture

The Kosmos server component is a loosely coupled network of collaborating POJOs, wired together via the powerful Spring IoC container.

Figure 4.1. Kosmos server architecture

Obviously, the most important POJOs are the services themselves. As the monitored resources and their interfaces vary a lot, there is no uniform way for the concrete services to access them. Services use various techniques to get the information requested, ranging from simple web crawling to using remote APIs. The actual techniques are documented in the javadocs of the appropriate XxxServiceImpl implementation classes.

The common features of the services are factored out to the AbstractKosmosService class. This where the initialization and static content storage gets done. You should start learning the server component code by studying the javadocs of this class. Also, to understand the static store mechanism, please take a look at the StaticContentStore interface, and WebdavStaticContentStore as a sample implementation.

The service methods themselves are intercepted by a fairly simple AOP interceptor that stores service method results in an EHCache-based cache, keyed by the service method invocation arguments. If the same service method is invoked again with the same arguments, the interceptor tries to look up the return value in the cache first. It delegates to the service POJO only in case of cache miss. All this is completely transparent for the service POJOs.

There is another useful, infrastructure layer mechanism to achieve performance improvement: scheduled updates. Configuring the update trigger in kosmos-services-servlet.xml, you can schedule automatic service reloads at given periods or times. For example, you can schedule a very expensive Subversion repository traversal at 2 o'clock in the morning every day, so the portal will reflect up-to-date results by the time you get to your browser. Scheduling is done using the powerful Quartz library and gives you extreme flexibility.

From the server to the portlets, the data is transferred simply by instantiating the POJO classes in the hu.midori.kosmos.model package and sending them over the wire using Hessian.

Again, all this is very simple and lightweight.

Portlets architecture

The portlets are extremely simple: they just connect the appropriate service, download a collection of DTOs and render the JSPs. They do some basic processing of the portlet init parameters and the request parameters, but this is very easy to understand from the source code.

That's it.

Appendix A. Copyright

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