Difference between revisions of "Procedure Infrastructure upgrade"

Revision as of 18:31, 8 April 2014

Preparation of the upgrade plan

This page http://wiki.i-marine.eu/index.php/Resources_Upgrade#gCube_Upgrade contains the list of gCube upgrades perfomed in iMarine so far.

Upgrade Activities

When dealing with an upgrade we should deal with different categories of components:

• Containers
  • gHN
  • Smartgears
• gCube Services
  • gCF based
  • Smargears based
• Portal and Portlets

Containers upgrade

The infrastructure is equipped with 2 types of containers :

• gHN : customisation of a Globus WS core 4.0.4 container
• SmartGears : a set of extension to any Servlet based container to enable registration and activation on the infra of webapps ( at the moment only tomcat is installed)

The main documentation regarding the containers is the gCube Admin guide:

• gHN : https://gcore.wiki.gcube-system.org/gCube/index.php/Administrator_Guide
• Smartgears: https://gcube.wiki.gcube-system.org/gcube/index.php/SmartGears_gHN_Installation

gHN

The gHN unfortunately implements an old flat classloader schema, which means that common and application libs are all shared and stored in the same folder. When a new version of the gHN is available we should understand which changes have been applied. The typical changes are:

• a new version of the libraries part of the gHN
• a new version of the web services part of the gHN
• a change on the configuration of the GHNgCube Hosting Node.

At this level of maturity the gHN upgrades difficultly introduce not backward compatibilities, which should make life easier..

In order to upgrade an existing installation we have been always using 2 type of scripts:

• upgrade script: The script downloads the new version of the gHN from Maven, removes the old libraries and copies the new ones by keeping the existing gCube Services installed. He modifies also the existing configuration if needed. In case one of the existing base gCube services ( Deployer, GHNgCube Hosting Node. Manager, ResultSet) needs to be updated it takes care also of undeploy the old version and deploy the new one
• clean script: The script runs a reinstallation of the gHN by keeping only the gCube service state. it can be needed in case of changes of java version ( e.g. move from java 6 built artifacts to java 7) as well

The latest versions of the scripts are available on svn at:

https://svn.research-infrastructures.eu/d4science/gcube/trunk/ghn-distribution/upgrade-scripts/

The rules behind the execution of the upgrade or the clean script in a running installation are :

• if the gHN is empty ( the gHN is not running any other web service other than the basic gCube ones) it's always better to run a clean script
• if most of the libraries part of the gHN, the gCube services installed and their deps have changes better to run a clean script
• if only part of the the libraries or the conf of the gHN has changed, better to always run an upgrade script.

Of course the main difference between the 2 scripts is the result. The upgrade script does not require any other action from the site manager, while the clean script requires that the gCube services previously installed on the node have to be reinstalled. ( see section on service upgrade)

SmartGears

In the case of SmartGears containers we are in front of the latest generation servlet containers, which implement separate classloaders for common and each applications and in most of the cases the upgrade is a really simple procedure.

The upgrade is a combination of 2 scripts:

• Download scripts : https://gcube.wiki.gcube-system.org/gcube/index.php/SmartGears_gHN_Installation#Upgrade, which downloads the version to install from Nexus
• Install script : https://gcube.wiki.gcube-system.org/gcube/index.php/SmartGears_gHN_Installation#Installation, which first removes the previous installed components if present.

gCube service upgrade

The upgrade of gCube Services depends on the nature of the services and the technology used for their development

gCF based

gCube Services gCF based are the oldest categories of Web ServiceSelf-contained, self-describing, modular application that can be published, located, and invoked across the Web. Web services perform functions that can be anything from simple requests to complicated business processes. Once a Web service is deployed, other applications (and other Web services) can discover and invoke the deployed service. developed in gCube: they are developed using the gCF ( gCore Framework) , they run in a gHN and they are packaged in a bundle called gar archive (i.e. deployer-service.gar). Also in this case we have 2 possible gar archives:

• Normal gar archive : which contains the service implementation, the config and the wsdl
• Full gar archive: which in addition contains all the service runtime dependencies.

The different service packaging is required because it reflects the different nature of the gCube services and their deployment model

Core services

The Core Service also named Enabling layer services https://gcube.wiki.gcube-system.org/gcube/index.php/Core_Services_Installation) are the minimal set of gCube Services needed to setup and manage a gCube infrastructure. Due to their nature and deployment scenario they should be installed /upgraded manually. Given that a manual installation is requested the Full gar archive is preferable cause it install together with a service the needed dependencies. Please note that not all the Core Services have a Full Gar cause this has been introduced when moving to Maven, and not all of them have been ported yet. In case the where the Full Gar is not available the service dependencies are listed on the Admin guide. In the case of manual upgrade the following actions should be performed:

Container stop:

$GLOBUS_LOCATION/bin/gcore-stop-container

Old service undeployment :

$GLOBUS_LOCATION/bin/gcore-undeploy-service ServiceName

New Service deployment:

$GLOBUS_LOCATION/bin/gcore-deploy-service ServiceName-full.gar

Please note that this operation removes together with the service implementation and dependencies also the configuration files ( among them the important jndi-config.xml). So in case of upgrades they should be recollected from the backup ( a GHNgCube Hosting Node. backup is always performed by the upgrade script)

Application services

The services that implement the Application logic and they are not fundamental in a gCube infrastructure deployment. They are installed using the Dynamic Deployment facilities implement by gCube amd part of the Resource and VREVirtual Research Environment. Management area (https://gcube.wiki.gcube-system.org/gcube/index.php/VRE_Management)

In details each gHN is equipped with a gCube service ( Deployer) which is responsible for the installation of the packages on the node. The Deployer is invoked by another gCube service ( the Resource Manager ) to deploy the packages taken from Maven. In the process another gCube Service is involved ( the Software Gateway ) which is responsible for the dependencies resolution. In order to upgrade a service using the Dynamic deployment, we should make sure that the previous version of the service has been previously removed. This process therefore is always used in junction with an upgrade of the gHN of type clean, that removes the previously installed service and its dependencies.

The upgrade using the Dynamic Deployment facilities can be performed directly from the Portal trough graphical interface.( LINK TO INCLUDE)

SmartGears based

As said SmartGears based services are JAVA JAXWS or JAXRS service deployed on a servlet based container ( Tomcat at the moment). They are packaged as a web application archive ( war) therefore each archive includes by default the service implementation and its dependencies. At the moment no gCube Core service has been deployed using this technology therefore only Application services are present in this category.

There are two ways of upgrading an existing gCube Service Smartgears based;

• Using the Tomcat Manager application ( where is enabled )
• Manually removing the previous version of the service and placing the new war under the $CATALINA_HOME/webapps folder.

The upgrade of a gCube Service SmartGears based can be performed exploiting the underlying container facilities of hot deployment, but this feature is not suggested in a production environment due to Memory Leaks. Therefore a container restart is always recommended.