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author | 2018-07-31 18:25:39 +0100 | |
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committer | 2018-07-31 18:27:31 +0100 | |
commit | af74a6270d6ab6badf04a97495a6ef8ccded9b4b (patch) | |
tree | 2c7a536e54207a0870ca2008ce457a64de917ab9 /src/site-docs/adoc/fragments/apex-intro/introduction.adoc | |
parent | 9e318f20f2e64970bf3c2e3a5532c516231a6f8a (diff) |
Adding first set of apex-pdp document changes
Adding document changes for auth, context, core, model, services & the
main apex-pdp module.
Change-Id: Id0d026baa258f1dc6998978f9911f3c4a73b5b3b
Issue-ID: POLICY-867
Signed-off-by: ramverma <ram.krishna.verma@ericsson.com>
Diffstat (limited to 'src/site-docs/adoc/fragments/apex-intro/introduction.adoc')
-rw-r--r-- | src/site-docs/adoc/fragments/apex-intro/introduction.adoc | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/src/site-docs/adoc/fragments/apex-intro/introduction.adoc b/src/site-docs/adoc/fragments/apex-intro/introduction.adoc new file mode 100644 index 000000000..b936ef51b --- /dev/null +++ b/src/site-docs/adoc/fragments/apex-intro/introduction.adoc @@ -0,0 +1,57 @@ +// +// ============LICENSE_START======================================================= +// Copyright (C) 2016-2018 Ericsson. All rights reserved. +// ================================================================================ +// This file is licensed under the CREATIVE COMMONS ATTRIBUTION 4.0 INTERNATIONAL LICENSE +// Full license text at https://creativecommons.org/licenses/by/4.0/legalcode +// +// SPDX-License-Identifier: CC-BY-4.0 +// ============LICENSE_END========================================================= +// +// @author Sven van der Meer (sven.van.der.meer@ericsson.com) +// + +== Introduction to APEX + +APEX stand for Adaptive Policy EXecution. +It is a lightweight engine for execution of policies. +APEX allows you to specify logic as a policy, logic that you can adapt on the fly as your system executes. +The APEX policies you design can be really simple, with a single snippet of logic, or can be very complex, with many states and tasks. +APEX policies can even be designed to self-adapt at execution time, the choice is yours! + +.Simple APEX Overview +image::apex-intro/ApexSimple.png[Simple APEX Overview] + +The Adaptive Policy Engine in APEX runs your policies. +These policies are triggered by incoming events. +The logic of the policies executes and produces a response event. +The __Incoming Context__ on the incoming event and the __Outgoing Context__ on the outgoing event are simply the fields and attributes of the event. +You design the policies that APEX executes and the trigger and action events that your policies accept and produce. +Events are fed in and sent out as JSON or XML events over Kafka, a Websocket, a file or named pipe, or even standard input. +If you run APEX as a library in your application, you can even feed and receive events over a Java API. + +.APEX States and Context +image::apex-intro/ApexStatesAndContext.png[APEX States and Context] + +You design your policy as a chain of states, with each state being fed by the state before. +The simplest policy can have just one state. +We provide specific support for the four-state link:https://www.researchgate.net/publication/303564082_Apex_An_Engine_for_Dynamic_Adaptive_Policy_Execution[MEDA (Match Establish Decide Act)] policy state model and the three-state link:https://en.wikipedia.org/wiki/Event_condition_action[ECA (Event Condition Action)] policy state model. +APEX is fully distributed. +You can decide how many APEX engine instances to run for your application and on which real or virtual hosts to run them. + +In APEX, you also have control of the __Context__ used by your policies. +Context is simply the state information and data used by your policies. +You define what context your policies use and what the scope of that context is. +__Policy Context__ is private to a particular policy and is accessible only to whatever APEX engines are running that particular policy. +__Global Context__ is available to all policies. +__External Context__ is read-only context such as weather or topology information that is provided by other systems. +APEX keeps context coordinated across all the the instances running a particular policy. +If a policy running in an APEX engine changes the value of a piece of context, that value is is available to all other APEX engines that use that piece of context. +APEX takes care of distribution, locking, writing of context to persistent storage, and monitoring of context. + +.The APEX Eco-System +image::apex-intro/ApexEcosystem.png[The APEX Eco-System] + +The APEX engine (AP-EN) is available as a Java library for inclusion in your application, as a microservice running in a Docker container, or as a stand-alone service available for integration into your system. +APEX also includes a policy editor (AP-AUTH) that allows you to design your policies and a web-based policy management console you use to deploy policies and to keep track of the state of policies and context in policies. +Context handling (AP-CTX) is integrated into the APEX engine and policy deployment (AP-DEP) is provided as a servlet running under a web framework such as link:http://tomcat.apache.org/[Apache Tomcat]. |