User Guide
This document explains how to install, configure, run PEtALS and work with it.
PEtALS Team Marie Sauvage
- July 2007 -
(CC) EBM WebSourcing - This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/
User Guide
Table of Contents
PEtALS ................................................................................................................................................. 4 1. Presentation ........................................................................................................................................ 5 1.1. PEtALS ................................................................................................................................... 5 1.2. Components ............................................................................................................................. 5 1.2.1. Binding Components ....................................................................................................... 5 1.2.2. Service Engines .............................................................................................................. 6 1.2.3. Samples ........................................................................................................................ 6 1.3. Service units and service assemblies ............................................................................................. 6 2. Installation ......................................................................................................................................... 7 2.1. Pre-Requisites .......................................................................................................................... 7 2.2. Installation ............................................................................................................................... 7 2.3. Directory structure .................................................................................................................... 7 3. Configuration ...................................................................................................................................... 9 3.1. Topology configuration: the topology.xml file ................................................................................ 9 3.1.1. Domain configuration ...................................................................................................... 9 3.1.2. Containers configuration ................................................................................................ 10 3.2. Container global properties : the server.properties file .................................................................... 12 3.3. Loggers configuration : loggers.properties .................................................................................... 12 3.4. JBI Exchange Optimizations ...................................................................................................... 13 3.4.1. Acknowledgement bypassing .......................................................................................... 13 3.4.2. Source content compression ............................................................................................ 13 3.4.3. more to come... ............................................................................................................ 13 4. Start & Stop PEtALS ......................................................................................................................... 14 4.1. Starting PEtALS ..................................................................................................................... 14 4.2. Stopping PEtALS .................................................................................................................... 14 5. Management ..................................................................................................................................... 15 5.1. Install/Uninstall components ...................................................................................................... 15 5.1.1. Install/Uninstall with repertories ...................................................................................... 15 5.1.2. Install/Uninstall via web administration console .................................................................. 15 5.2. Monitoring PEtALS ................................................................................................................. 15 5.3. Management alternatives .......................................................................................................... 16 5.3.1. JMX Management via HTTP .......................................................................................... 16 5.3.2. JMX Management via RMI ............................................................................................ 16 5.3.3. Management in console mode ......................................................................................... 17 5.3.4. Management via Ant ..................................................................................................... 18 6. PEtALS domain ................................................................................................................................ 19 6.1. Distributed environment ........................................................................................................... 19 6.1.1. A distributed JNDI directory ........................................................................................... 19 6.1.2. JBI Service-Endpoints access .......................................................................................... 19 6.1.3. JBI MessageExchange delivery ....................................................................................... 19 6.1.4. PEtALS network ........................................................................................................... 20 6.1.5. Stop, Restart and Shutdown a server ................................................................................ 20 7. Known issues and resolutions .............................................................................................................. 21 8. Links ............................................................................................................................................... 22
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List of Figures
1.1. PEtALS ........................................................................................................................................... 5
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PEtALS
PEtALS
PEtALS is the highly distributed Open Source ESB hosted by OW2. PEtALS delivers the OW2 Java Business Integration (JBI) platform. PEtALS provides lightweight and packaged integration solutions, based on JSR-208 specifications, with a strong focus on distribution and clustering.
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Presentation
Chapter 1. Presentation
1.1. PEtALS
PEtALS helps you to integrate your Enterprise Business Units in order to provide a value added global solution. By assembling all your enterprise elements, you can provide new applications by re-using some existing ones. Thus, all your applications expose their logic by exposing services. This concept is known as a Service Oriented Architecture (SOA). PEtALS offers a solid backbone for your enterprise Information System and acts as a Bus where all your data are exchanged. PEtALS connects services to each others. Petals is an Enteprise Service Bus (ESB).
Figure 1.1. PEtALS
1.2. Components
1.2.1. Binding Components
The binding components allow the transfert of a request from an external service consumer to the JBI environment, as well as the transfert of an "internal" request to an external service provider. The actual existing BC are : • Filetransfer : allows to send and to receive files
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Presentation
• FTP : allows to put, get, or detect files on a ftp server • JMS : allows to interact with an external JMS Destination (queue or topic) • Mail : allows to send or receive files from or to an external mail service • Soap : allows to interact with external Web Services and to expose JBI services as Web Services • XQuare : allow users to interact with databases
1.2.2. Service Engines
The actual existing SE are : • CSV : transforms a CSV document in an XML document • EIP : allows to implement some Enterprise Integration Patterns • Forward : allows to chain calls to service engines before forwarding the result to an output service • Pojo : allows to deploy Java classes as Services • RMI : provides access to the JBI bus implementation context from an external RMI client • XSLT : allows to process xml transformations based on xsl style sheet
1.2.3. Samples
Some sample components are delivered with PEtALS : • SampleClient : a graphical client to tests other components • HelloWorld : say Hello... • Clock : give the current time • PerfConsumer/PerfProvider : two components running together to test core performances of one or several PEtALS servers.
1.3. Service units and service assemblies
** to complete **
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Installation
Chapter 2. Installation
2.1. Pre-Requisites
• Java : to run PEtALS, you need a Java JRE 1.5. The Sun JVM can be downloaded on their site : http://java.sun.com/javase/downloads/index_jdk5.jsp • PEtALS : Download the latest distribution archive file (bin) on the forge : http://forge.objectweb.org/project/ showfiles.php?group_id=213
2.2. Installation
To install PEtALS, you just need to explode the downloaded archive into the directory where you want PEtALS to be installed, which will be the PEtALS root path. Generally, PEtALS find itself where it is installed. On certain systems, the root path can not be found, and a PETALS_HOME environment variable has to be set : • On Unix like system : export PETALS_HOME=... • On Windows like system : set PETALS_HOME=...
2.3. Directory structure
•
ant-sample : includes a sample file containing exemples of ant task definitions and call and the lib you have to import
in your project to use these ant tasks. • • • •
bin
: includes scripts to launch PEtALS on Unix (*.sh) or Windows (*.bat) systems. : includes all components archives distributed with PEtALS.
components conf
: includes all PEtALS configuration files.
: includes all demonstration components and service assemblies that illustrate application composition with PEtALS (ex : Mortgage demonstrator).
demos
•
: the directory where you have to put components (service engines or binding components) or service assemblies to have them automaticaly installed (or deployed) and started in the PEtALS environment.
install installed : components and services assemblies are automaticaly copied into this directory after a succesful installation
•
(or deployment). • • • • •
joram lib
: includes all files generated by the joram transporter during PEtALS execution.
: includes all libraries used by PEtALS system. : includes all logs generated during PEtALS execution. : contains elements previously installed that have not been correctly recovered.
logs
lost+found repository
: includes all the libraries, config files (etc) of the installed or deployed components, shared libraries and service assemblies.
samples schema
• •
: contains some samples components
: includes all xml schemas used by PEtALS.
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Installation
•
: components and services assemblies are automaticaly copied into this directory after a succesful uninstallation (or undeployment).
uninstalled work
•
: used by PEtALS system to put components or SA archives during installation or deployment phases.
Note
Note that depending on the distribution you've downloaded, complete or not, some directories as demos or samples may not appear on your first install, you just have to create it when you'll need.
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Configuration
Chapter 3. Configuration
3.1. Topology configuration: the topology.xml file
PEtALS is aiming distributed environments. To fullfill this orientation, PEtALS nodes of a common topology are defined in a shared file; the topology.xml file. This file must respect the contraints defined in the petalsTopology.xsd XML schema file. You can find an example of topology configuration in the file named topology_example.xml. The topology configuration is decomposed in 2 main sections, the domain configuration and the containers configuration.
3.1.1. Domain configuration
The PEtALS topology is identified by a PEtALS domain. This configuration part defines the domain behavior and the common resources of the domain. Here is an example of domain definition:
224.7.65.52 8000 org.objectweb.petals.communication.jndi.client.naming.NamingContextFactory domain
mode attribute: The mode of the domain, possible values are static, dynamic and standalone. This field defines the behavior of the PEtALS domain, if it can expand or shrink, or if it accept only one node. See Chapter 6, PEtALS domain for further details.
Note
The standalone mode is not implemented yet. name attribute: The name of the domain. It is the identifier of a PEtALS domain.
multicast
Optional. Defined the use of multicast IP messages within the PEtALS domain. If the company network allows multicast communication, the definition of this element is recommanded. See section 6 for further details.
Note
The use of multiple unicast messages instead of multicast message is not implemented yet. So this element is mandatory for the moment.
ip port jndi
the ip to use to send and receive multicast messages. the port to use to send and receive multicast messages.
Define the JNDI resource. All the nodes belonging to the domain access to this JNDI resource. See Chapter 6, PEtALS domain for further details. 9
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factory
The JNDI factory class name. Used to access to the JNDI Initial context. The PEtALS JNDI factory class name is org.objectweb.petals.communication.jndi.client.naming.NamingContextFactory. Optional. The host name or IP of the JNDI server. If the PEtALS JNDI resource is the PEtALS one, this field must not be set. Optional The container name of the JNDI server. If the PEtALS JNDI resource is the PEtALS one and it must be externalized, this field must be set. Optional. The port to connect to the JNDI server.
host
container
port
3.1.2. Containers configuration
The PEtALS topology is composed of one or several PEtALS nodes or containers. This configuration part defines the container identifiers and resources it uses within the topology. Here is an example of the containers configuration:
192.168.1.148 description of the features of Container1 7720 7700 7780 0 petals petals 7740 7760 7800 192.168.1.50 description of the features of Container2 7721 test test 7701 7781 1 petals petals 7741 7761 7801
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Configuration
container
name attribute: The name of the container. Used as identifier in domain communications, must be unique in the domain.
host
Optional in dynamic mode. The host name or ip address of the container. If not set in dynamic mode, the container uses the default IP address. Optional. The description of the container.
description configuration
The configuration of the services used by the PEtALS container.
networkservice
The network service, used to discover new / started / stopped / removed PEtALS node.
port
The binding port. Used to receive dedicated messages from the domain.
jmxservice
The JMX service, used to manage MBean objects.
user password rmiport
Optional. The JMX user or login. Optional. The JMX password. The port used by the JMX RMI connection. MX server will be accessible via the address : service:jmx:rmi:///jndi/rmi://
if_of_the_host:rmiport/management/rmi-jmxconnector
httpport
the port used by the JMX HTTP connection. With a browser, the container will be accessible via the URL http:// ip_of_the_host:httpport to visualize the content of the JMX server.
joramservice
The JORAM service. Used by the PEtALS Transport layer to exchange JBI messages.
id user
The JORAM Id. The JORAM user AdminModule. to connect to the JORAM
password
The JORAM password to connect to the JORAM AdminModule. The port used by the JORAM agent to communication with the JORAM domain. The port used by JORAM to exchange message via TCP communication.
domainPort
tcpport
dreamservice
The DREAM sercvice. Used by the PEtALS Transport layer to exchange JBI messages.
port
The port used by DREAM to exchange message via TCP communication. 11
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Configuration
3.2. Container global properties : the server.properties file
The Container global properties are stored in a file named server.properties. These properties defines the default values used by the PEtALS container.
petals.container.name
Optional in standalone mode. The name of the container. Must match a container name defined in the topology configuration. Optional. The URL path to the PEtALS repository. PEtALS holds its JBI configuration in this repository and can recover this configuration from it. Optional. This property is used to set the behavior of the components in this container related to the message echange validation (see isExchangeOkayWith). This property set up the quality of service used by the transporter. Two QOS policy are settable: reliable or fast. The reliable policy assures the delivery of the messageExchanges when attempting exchange transfers. If a targeted component is unreachable by any reasson (crash, network failure...),the messageExchanges are persisted and would be delivered at the component recovery. No effort is provided on the duration of the transfers. The fast policy assures an optimized transfer of message Exchange. According to the location of the destination, a component on a local or on a remote PEtALS container (in distributed environment), the fastest transport protocol is used.
petals.repository.path
exchange.validation
transport.qos
routing.strategy
This property defines the routing strategy. Two kind of strategy can be defines: highest or random. The others parameters represent respectively the local ponderation, the ponderation of the remote active endpoint and the ponderation of the remote inactive endpoint. The random strategy chooses an endpoint in function of defined ponderations. The endpoints that have the strongest ponderation can be more easely choose in comparison with the others. The highest strategy chooses the first endpoint in the list that have the strongest ponderation.
3.3. Loggers configuration : loggers.properties
To initialize Monolog a monolog.properties file is needed in the classpath. The property monolog.classname of the loggers.properties file points to the logger implementation that is used in PEtALS. This file defines 5 differents loggers handler : • a console handler for the Petals logs with the DEBUG level • a file handler for the Petals logs with the INFO level • a console handler for the Joram logs with the DEBUG level • a file handler for the Joram logs with the INFO level • a console handler for the other logs with the DEBUG level
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Configuration
3.4. JBI Exchange Optimizations
3.4.1. Acknowledgement bypassing
Each JBI MessageExchange pattern ends with a "DONE" or "ERROR" message. The sender has to accept such messages, otherwise they are accumulated in the NMR (Normalized Message Router). This generate extra trafic, too, even in an In-Only exchange. Setting the org.objectweb.petals.messaging.noack property to "DONE" or "ERROR" message will not be sent through the NMR.
true
on the MessageExchange indicates that the
3.4.2. Source content compression
As the payload of a MessageExchange is XML (text), it can be interesting to compress it when messages are exchanged between different PEtALS nodes. Setting the org.objectweb.petals.transport.compress property to true on the MessageExchange indicates that the PEtALS transport layer will compress the Source content of the exchange messages.
3.4.3. more to come...
Some optimizations are planned for future PEtALS versions, here they are :
3.4.3.1. Batch mode
If consumers or providers send a very high number of messages, the transport layer can send them in a batch mode (each 1ms), avoiding repeated connections / deconnections. The transport layer use 2 differents connections, a standard one, and a "batch mode" one. Setting the org.objectweb.petals.transport.batch property to true on the MessageExchange indicates that this messages will be treated with the "batch mode" transport connection.
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Start & Stop PEtALS
Chapter 4. Start & Stop PEtALS
4.1. Starting PEtALS
1. Go to $PETALS_HOME/bin 2. Launch startup.sh or startup.bat :
# ./startup.sh
You can launch PEtALS in console mode, to be able to interact with it via the terminal. In this case, use the option -C in the terminal :
# ./startup.sh -C
Note
you can also use the 'java -jar server.jar' command line.
4.2. Stopping PEtALS
There is several ways to stop PEtALS : 1. If PEtALS is launched in a simple terminal, type + to stop the process 2. If PEtALS is launched in console mode, just type 'q' or 'x' and in the terminal :
# q
by typing q, PEtALS is stopped and component, SA, SL aren't uninstalled/undeployed by typing x, PEtALS is stopped and component, SA, SL are uninstalled/undeployed 3. If PEtALS is launched in background, launch the stop.sh script :
# ./stop.sh
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Management
Chapter 5. Management
PEtALS provides JBI management tasks accessible through JMX. There is 6 'top level' JBI management services : 1. Administration Service This service allows to retrieve single component or list of components, to find the nature (binding or engine) of a component, to retrieve system services and system information. For more information see AdminServiceMBean. 2. Deployment Service This service allows to deploy/undeploy service assemblies and to create/manage their LifeCycle (start, stop, shutdown). It allows to list Service Assemblies and Service Units that match a particular criteria (for ex : service units deployed to a particular component). For more information see DeploymentServiceMBean. 3. Installation Service This service allows to install/uninstall shared libraries and components and to manage (create, register, retrieve, destroy) InstallerMBean. Installers are used to perform real installation/uninstallation tasks on components. For more information see InstallationServiceMBean. 4. Logger Service This service allows to manage the loggers : create, remove, set configurations, etc. 5. Monitoring Service This service allows to set monitoring parameters of PEtALS server and activate or deactivate it. 6. PEtALS Administration Service This service allows to execute Petals specific administration tasks like shutting down the PEtALS container.
5.1. Install/Uninstall components
5.1.1. Install/Uninstall with repertories
Components can be installed directly by copying the .zip archives in the install directory of PEtALS. PEtALS will detect the new file and procede to the installation and start of the component. To uninstall a component, remove the .zip archive of the installed directory of PEtALS. PEtALS will detect the removal of the file and procede to the stop/shutdown/uninstall of the component. If you want to keep the component available, instead of deleting the file you can move it to the uninstalled directory of PEtALS.
5.1.2. Install/Uninstall via web administration console
See the monitoring documentation for further details.
5.2. Monitoring PEtALS
To monitor PEtALS domain, a monitoring console based on a web application is proposed. To use it, you need a servlet container like Tomcat. With the monitoring console, you can : • see the PEtALS servers started and stopped on the domaine
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Management
• control and set monitoring parameters for each PEtALS server started • view informations and stats about the domain See the monitoring documentation for more informations about pre-requisites, installation and usage.
5.3. Management alternatives
Alternatives are available to manage a PEtALS server and may offer access to other functionalities.
5.3.1. JMX Management via HTTP
The management of the JBI container is based on Java JMX (tm). An HTTP JMX connector is launched with the PEtALS server. This JMX Server allows you to manage JBI elements, trough the PEtALS tab. This connector can be accessed on your machine with a web browser at http://localhost:7080
Note
if multiple containers are started on the same machine, other ports are '7081', '7082', and so on. On the first page (Petals View), you'll have access to all services and components installer and engine MBeans :
5.3.2. JMX Management via RMI
An RMI JMX connector is launched with the server. So JMX functions can be accessed through a graphical RMI client, the JConsole coming with the Sun jvm for example. The JConsole is located in the $JAVA_HOME/bin directory of your environment, just launch jconsole.exe on Windows or jconsole on Linux.
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Management
At startup, JConsole prompt for a server to connect to. Go to the Advanced tab and connect with the following : service:jmx:rmi:///jndi/rmi://localhost:7700/management/rmi-jmx-connector.
Note
if multiple containers are started on the same machine, other ports are '7701', '7702', and so on. Once connected, you can find all MBeans exposed on the server, including the PEtALS management services under "MBeans" tab :
5.3.3. Management in console mode
The user can interact with PEtALS by starting it with startup.xx -C Once PETALS is started, commands can be wrote to the console: • hotdeploy -ZIP filePath- (or hd): install and start a component, a service assembly or a shared library • hotundeploy -ZIP fileName- (or hu): shutdown and uninstall a component, a service assembly or a shared library • path (or p) : display current file system path • setpath -Path- (or sp): change current file system path • jndi (or d) : display the naming directory • help (or h) : this help • stop (or q) : stop Petals
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Management
• shutdown (or x) : shutdown Petals (remove from the Petals network)
5.3.4. Management via Ant
You can have access to management function through Ant Tasks. These Ant tasks call the corresponding JMX tasks. See section 6.10.6 of the JBI Specification. You can find a sample xml ant build file in task allowing to manage Petals.
$PETALS_HOME/ant-sample/.
This ant file contains examples for each ant
5.3.4.1. Install a component
To install a component just run this ant task :
This will load a new InstallerMBean and execute the install method on this one. So component is completly installed.
5.3.4.2. Start a component
To start a component just run this ant task :
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PEtALS domain
Chapter 6. PEtALS domain
PETALS runs natively in a distributed way. The distributed environment is called a PEtALS domain.Three different domain mode are offered to the PEtALS users. The standalone mode restraints the definition of a single node in the PEtALS domain. Thus the container can be an enlighten version with some services bypassed, like the Network service and its discovery feature, the distributed PetALS JNDI resource, or some Transporters. The dynamic mode provides a PEtALS domain easily extendable and shrinkable. It is adapted to a development phase when nodes can be often added or removed from the domain. The weakness of this mode is that there is no control of the topology configuration. The static mode provides a PEtALS delimited domain. it is adapted to an exploitation environment where the network resources (port) must be controlled, and the containers participating to the domain are clearly identified.
6.1. Distributed environment
6.1.1. A distributed JNDI directory
PEtALS provides its own implementation of a JNDI directory, distributed amongst its domain nodes. Nevertheless, it is still possible to configure the PEtALS domain to use an external JNDI directory. To do so the host and port of the external JNDI directory must be specified in the topology configuration. With this configuration, all the nodes are connected to the same JNDI end point. With the PEtALS JNDI directory, aach PEtALS node contains a replication of the JNDI directory. When a modification occurs, it is synchronized through the replicated JNDi directories. The PEtALS node have a local reference to the distributed directory, to avoid the socket based access of a standard JNDI directory. It fasten the JNDI communication and bring better performance to the JNBi exchanges. It is possible to 'externalized' the JNDI directory if clients want to access to it; the PetALS user must specify the container name and the port on which the JNDI server would communicate with the JNDI clients. The clients use the standard JNDI API to connect and dialog with the PEtALS JNDI directory.
6.1.2. JBI Service-Endpoints access
A ServiceEndpoint registered by a JBI component is stored in the JNDI directory. Thus, all other JBI components (local to the server or hosted on another server) can see and use it. The ServiceEndpoint is holden in the JNDI directory until it is unregistered by its JBI component owner. If the server is stopped but the JNDI directory is still living (other PETALS servers are running, or the JNDI server is external), the ServiceEndpoint is still visible. When the related PETALS server is started again, the JBI component is restarted and it tries to register again this ServiceEndpoint. As this ServiceEndpoint is already referenced in the JNDI directory, this reference is returned to the component.
Note
The PEtALS JNDI directory is persisted in a file, so if all the PEtALS node are stopped, the ServiceEndpoint are still registered in the JNDI directory file. This feature is not implemented yet.
6.1.3. JBI MessageExchange delivery
The communication between the JBI components running on PEtALS node is transparent.
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PEtALS domain
A JBI MessageExchange for a ServiceEndpoint is sent to the component that has registered it,the component can be collocated or not to the sender. As a ServiceEndpoint is still active even if the server that hosts it is stopped, messages can be still sent to it. If the reliability transport QOS has been selected, these messages are put in the JORAM persistence, and will be delivered when the server that hosts this ServiceEndpoint starts again. Even if all PETALS servers are stopped, as the pending messages are physically stored on the server that hosts the sender, the messages will be delivered at startup (PETALS uses the JORAM store and forward mechanism). Otherwise, if the fast transport QOS has been selected, exceptions are raised up to the sender.
6.1.4. PEtALS network
The PEtALS nodes members of a PEtALS domain need to communicate each others to inform about their states or about node joining or leaving the domain. PEtALS proposes a service, the network service, to support these requirements. The network service is based on Jgroup technology, which permits to dispatch message amongst a group of network elements, detects new or failure elements, and many others functionalities. In the PEtALS domain, there is one node elected as the coordinator, basically the oldest started. This coordinator is the actor which decides to accept or not a new starting node. The PEtALS network behaves differently according to the domain mode used. In static mode, when a node is trying to join the domain, the coordinator verify its entire configuration against the topology configuration it hold. If a mismatch is found, it refuses the new node and notifies it with an explicit response. In dynamic mode, the coordinator verifies just if the new node doesn't try to use a ressource already used by another node (e.g a same port on a same host), and then accept it.
Note
The PEtALS JNDI directory relies on the network service to replicated its directory.
6.1.5. Stop, Restart and Shutdown a server
You stop a PETALS server when you terminate the jvm process (by "Ctrl-C" or "kill" command, or "stop" in the commandline mode). You normally see a "PETALS is stopped" message. At this point, the server is stopped but still referenced in the topology configuration (i.e. the other living nodes know that this server exists,even if it is stopped). When you start again this server, it retrieves its configuration and notifies through the PETALS topology that it is started. It eventually sends or receives pending messages. It is possible to 'shut down' a PEtALS server. It means that all the JBI SA, SL or component registered on the PEtALS container are undeployed and removed, so all the ServiceEndpoints it did expose are unregisted from the JNDi directory. Moreover, in dynamic mode, the server is definitely removed from the PEtALS domain and no more registed in the shared JNDI directory. You can shutdown the server by using the PetalsAdmin JMX service, or with the "shutdown" command in the commandline mode.
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Known issues and resolutions
Chapter 7. Known issues and resolutions
For up-to-date and complete informations about current bugs, see the bug tracker on the PEtALS forge. Connection refused to host 127.0.1.1 Some linux distribution (ubuntu for example) have bad /etc/hosts configuration file settings. The 127.0.1.1 address is defined in this file. Who must change this value to 127.0.0.1 if it is not already set
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Links
Chapter 8. Links
• The PEtALS Website : http://petals.objectweb.org • The JBI Specification : http://jcp.org/aboutJava/communityprocess/final/jsr208/index.html
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