Download The CAS Server - User Manual (DRAFT)

The CAS server – User Manual processing elements and the functionality they expose. The notification mechanism
may be used in order to make sure that, as soon as a relevant characteristic of the CAS
Server changes, all the orchestration nodes that require an update are notified. The
notification message contains information about the CASs installed on the CAS
Server, the methods/symbols implemented by the installed CASs that are available for
remote invocation (in the case of OpenMath symbols, the list of symbols that may be
used to formulate a call), the capabilities of the machines on which the CASs are
installed.
Call resolving mechanism - It is not uncommon for OpenMath documents to use
references to other OpenMath documents. When submitting a SCSCP call containing
OpenMath references (OMRs), the target documents may be present on the machine
to which the call is submitted but most often, they reside on other machines. CAS
Server implements a resolving mechanism that makes sure that any references used in
a SCSCP call are resolved, i.e. the OpenMath objects referenced by the OMRs are
made available on the execution CAS Server. This is achieved by communicating with
partner CAS Servers from which target nodes are extracted and retrieved.
Execution management - The capabilities that fall into this section may be more
relevant when the CAS Server is integrated within an orchestrated architecture.
Controlling the execution of a certain task requires several capabilities: pausing a
task, resuming a task, cancelling a task, “a priori” result setting capability – the ability
to specify the probable result of the executed task.
Installation Steps
Prerequisites
In order to successfully install CAS Server, several software packages several configurations
must be done and several software packages must be already installed. The prerequisite
environment consists of:
Operating System: any Linux distribution supported by a full installation of Globus
4.2 Grid middleware packages may be used. Alternatively, a Windows distribution
may be used if the security features offered by the GSI security package of Globus
Toolkit are not required. For the rest of the document we assume that a Globus Toolkit
compliant Linux distribution is used.
Java SDK version 1.5 or later (http://java.sun.com/javase/downloads) – the Java
Software Development Kit required for compiling and executing the CAS Server and
other additional software packages such as Globus Toolkit.
Apache Ant version 1.6 or later (http://ant.apache.org/) - is required for building and
installing the package.
Apache ActiveMQ version 5 (http://activemq.apache.org/) – these packages must be
registered to the Java CLASSPATH environment variable and an ActiveMQ broker
should be configured and started before starting any component of the CAS Server
(see Section “Installing the packages”). It is used for interconnection of several CAS
Server internal components.
Apache Tomcat version 5.5 (http://tomcat.apache.org/) – this is optional and is
necessary only if you want to run the ActiveMQ broker embedded in the Tomcat
Container
PostgreSQL database server version 8 or later (http://www.postgresql.org/) with
support for PL/pgSQL – required for persistency by the CAS Server. Once installed,
an SQL configuration script available within the CAS Server installation package will
be executed in order to create the necessary database structure.
SCIEnce IeAt Team
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