Introduction to enhydra shark)

Jieshao

The enhydra Shark Project delivers a Workflow Server in a different way.

Enhydra shark is an extensible workflow engine framework that includes a standard implementation fully based on the WfMC specification and uses xpdl (without any new extensions of its own) as the workflow Flow Definition Format, the "toolagents" API of WfMC is used as the execution form on the server side of the system activity.

The enhydra JaWE graphic xpdl editor can be used to generate xpdl process definitions for enhydra shark!

Toolagents can be used for Javascript, JDBC access, EJB access, pure Java class, CORBA call, email, WebService call, and so on...

The process and activity instance are stored through a configurable persistent API. The persistence layer adopts the lightweight enhydra dods o/R Mapping Tool. More heavyweight J2EE EJB persistent layer selection solutions are shown below.

Each single component (persistence layer, transaction management, script engine, process library...) can be used for its standard implementation or expanded/replaced by a specific project module.

In this way, enhydra shark can be used as a simple "Java library" located in servlet or swing applications or running in J2EE containers (supporting Session Bean APIs and for EJB persistence ", it can be used by corba orb or web services.

The workflow engine Kernel provides configurable LRU caches for active workflow objects in High-load environments. Cache can be disabled during cluster deployment.

When a workflow is running, the WfMC wdf api specification is used to append the JaWE editor or selfwritten program to the runtime instance information or even modify the instance. With this method, enhydra shark supports dynamic workflow mechanisms and can modify itself to support exception handling in more complex workflow environments or organizations.

Generally, swing-Based Management GUI can be used for management. JMX extensions and HTML-based management clients can also be used for management.

Other APIs can be used for knowledge base access, logs, knowledge base persistence, event notifications, and Script Engine adapters designed for transition evaluations.

Objectweb workflow workgroup

On July 6, December 2003, the new objectweb workflow working group meeting was held for the first time.

The goal of this meeting is to determine feasible collaboration rules between the current objectweb workflow project, namely, "enhydra shark", "cow", and "Bonita.
The consensus reached at the meeting was that the APIs of these components should follow their respective standards (WfMC, OMG, and BPEL ). These components will be part of an independent workflow engine project in the future.

All components will not depend on specific runtime environments (swing, Servlets, J2EE/EJB, and CORBA ...).

To select a general component model ("glue"), we recommend that you use "Fractal ".
A new email list has been created to facilitate discussion of routine workflow workgroup issues and support collaboration between projects. The list can be found on the http://www.objectweb.org/wws/info/wow.
The other consensus was that enhydra JaWE was used as a general editor for xpdl-based process definition.

The Research on WfMC WDF (workflow definition function) will show whether the API is suitable for dynamic modification of the process and activity instance. If WDF is the first choice, JaWE supports this API for graphical viewing and instance modification during running.

The following lists the components that are initially determined:

Model Library
Ing module, including tooling to toolagents, scripting language/engine, and participants (users and groups)
Process and activity instance persistence (based on enyhdra dods, Speedo, EJB's ,...)
The script engine adapter/wrapper is applicable to the process conversion evaluation of different scripting languages (JavaScript, Python.
Perseus ?)
Transaction Management (gotm ?)
Toolagents
Dispatch API for dynamic participant ing
Notification API (jabber, JMS ,...)
Logs (system logs and management activity logs)
Deadline (deadline) Management (activity deadline (deadlines), activity duration (durations ),...)
Notebook (quartz, J2EE timer services ,...)
Escalation)

Enhydra shark Architecture

The current enhydra shark Architecture Objectives are shown in the following figure based on the shark components that have reached consensus.

(Please note! This document shall indicate the original translator Rosen Jiang and the source:Http://blog.csdn.net/rosen)