Table of Contents



Attribute-based access control. Attribute-based access control defines an access control paradigm whereby access rights are granted to users through the use of policies which combine attributes together. The policies can use any type of attributes (user attributes, resource attributes, object, environment attributes etc.). Source: Wikipedia


"Access Control List" (ACL). An access control list (ACL), with respect to a computer file system, is a list of permissions attached to an object. An ACL specifies which users or system processes are granted access to objects, as well as what operations are allowed on given objects. Source: Wikipedia

Action Handler

Action handlers are external service points the engine utilizes to get things done it can’t do it itself. Hence the engine (usually being the "server") now becomes the client and sends out request to a suitable Action Handler.

Apache Cassandra

Apache Cassandra is an open source distributed database management system designed to handle large amounts of data across many commodity servers, providing high availability with no single point of failure. Cassandra offers robust support for clusters spanning multiple datacenters, with asynchronous masterless replication allowing low latency operations for all clients. Source: Wikipedia

Application (Node)

An 'Application Node' within the MARS Model is describing the end user perspective towards IT. Typically an Application consists of a number of resources / Resource Nodes.



Setting up an basic environment, e. g. using a boot loader.



see Apache Cassandra.


"Configuration Item". Configuration information within the MARS Model. See also CMDB.


"Command Line Interface". Command line interface that enables the direct input of commands.


"Configuration Management Database". Contains the information supplied by the customer about construction and composition of the defined IT environment as per the MARS model.



Database Management System

Dependency Map

Model showing dependencies between different Configuration Items/Services, aka MARS-Model.

Dependency Model

see MARS Model



Amazon Elastic Compute Cloud (EC2) is a central part of’s cloud computing platform, Amazon Web Services (AWS). EC2 allows users to rent virtual computers on which to run their own computer applications. Source: Wikipedia


An event is an action or occurrence detected by the program that may be handled by the program. Source: Wikipedia




"A graph is a representation of a set of objects where some pairs of objects are connect by links." Source: Wikipedia


See HIRO Graph.



High Availability

High Availability

Concept that provides systems available 99% (or more) of the time.


HIRO Command Line Interface Tools. A set of tools to simplify the most common graph operations for Knowledge Items, MARS Nodes and Issues.

HIRO Engine

Issue processing and logic core

HIRO Graph

HIRO Graph is a distributed graph storage holding data defined in OGIT. It is also the underlying storage engine for the HIRO.



Identity and Access Management.

Information situation

The information situation is part of an Issue and consists of all information available for decision taking. It is extend and/or updated by Knowledge Items until the conclusion of the Issue task. The choice of Knowledge Item that will be applied next to an Issue is based on the information situation.


An Issue is a task which, in a formalized manner, is handed over to the engine via an interface. The engine then attempts to resolve Issues with the help of Knowledge Items. Technically speaking, an Issue is a data container, collecting information from various sources.

Issue Condition

The "Issue Condition" (IC) is the state the data is in. The Issue Condition defines which state triggers the Knowledge Item(s) associated with this particular IC.



"Java Database Connectivity", an API which defines how a Java client can access a database


"JavaScript Object Notation" (JSON) is a lightweight data-interchange format. It is easy for humans to read and write. It is easy for machines to parse and generate. It is based on a subset of the JavaScript Programming Language, Standard ECMA-262 3rd Edition - December 1999.


Java(tm) Development Kit


The "Java Naming and Directory Interface" (JNDI) is a Java API for a directory service that allows Java software clients to discover and look up data and objects via a name.


Java(tm) Runtime Environment



"Kafka is a distributed, partitioned, replicated commit log service. It provides the functionality of a messaging system, but with a unique design." from Kafka introduction


The KI Editor is the central maintenance tool for Knowledge Items.

Knowledge Item

A "Knowledge Item" (KI) is a piece of knowledge data which is used to resolve Issues. A Knowledge Item determines the necessity of its execution by checking the state of presented information. In case the information points to a problem that can be solved by the Knowledge Item it further gathers information to determine how to proceed or executes commands to directly address the presented Issue.

Knowledge Pool

The Knowledge Pool is the sum of all Knowledge Items used by the engine.



Machine (Node)

An Machine Node within the MARS Model is usually describing the physical infrastructure component (hardware), that is capable of running one to many software components.

Machine Learning Service (MLS)

A machine learning service is a service that uses statistical techniques to give computer systems the ability to "learn" (e.g., progressively improve performance on a specific task) from data, without being explicitly programmed.


The MARS Model describes and categorizes IT objects within a system and represents the relationships between them.



A node in general is an object with a Graph structure. The engine builds a graph structure out of the MARS Model description, so any object contained in a MARS model is represented by a node in the Autopilot database.

Node Type

Within the HIRO Graph database there are four basic types of nodes: Machine, Software, Resource and Application.



OAuth is an open standard to authorization. OAuth provides client applications a secure delegated access to server resources on behalf of a resource owner. Source: Wikipedia


The "Open Graph of IT" aims to build a semantic representation of all IT and its interaction with business processes and people, also known as the "Facebook of IT". The OGIT ontology project targets to provide a common language by defining an ontology for the Graph of IT. Find more information at OGIT Repository.



Policy based access control. See [ABAC]


Policy Decision Point. See [ABAC] and [XACML]




"Role-based-access-control" (RBAC) is a policy neutral access control mechanism defined around roles and privileges. The components of RBAC such as role-permissions, user-role and role-role relationships make it simple to perform user assignments. Source: Wikipedia


"Relational Database Management System", a database management system based on the relational model


Regular Expression


"Representational State Transfer" (REST) is a software architecture style consisting of guidelines and best practices for creating scalable web services. REST is a coordinated set of constraints applied to the design of components in a distributed hypermedia system that can lead to a more performant and maintainable architecture. Source: Wikipedia

Resource (Node)


"RPM Package Manager" (RPM) (originally Red Hat Package Manager; now a recursive initialism) is a package management system. Source: Wikipedia



Arago "Standard Data Format". A proprietary but open data format developed by Arago for exchange between ITSM systems and HIRO Connect.

Software (Node)


Single Sign-On


Time Series

A time series is a sequence of data points, measured typically at successive points in time spaced at uniform time intervals.


Time To Live


A token can either be a session identifier or a substitute for authorization credentials, depending on the context of the application. It serves to identify users or applications. For more information please refer to Tokenization or Session ID





The "Well-Known Addresses" (WKA) scheme is a mechanism that allows cluster members to discover and join a cluster using unicast instead of multicast. WKA is enabled by specifying a small subset of cluster nodes (referred to as WKA nodes) that are able to start a cluster. The WKA node starts the cluster and the other nodes join it through this WKA node. If the WKA node is down, the cluster breaks, and the nodes will not be able to communicate with each other.

The system should have at least two well-known address (WKA) members in order to work correctly and to recover if a single WKA member fails.


This typically refers to the WSO2IS component.


The WSO2 Identity Server is an open source identity & entitlement management server having support for Information Cards, OpenID and XACML. Source: Wikipedia.



"Extensible Markup Language" (XML) is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all free open standards."" Source: Wikipedia


XML name space


"XML Schema Definition". A schema is a collection of metadata, that describes and validates data in an XML environment.



"YAML is a human-readable data serialization format that takes concepts from programming languages such as C, Perl, and Python, and ideas from XML and the data format of electronic mail" Source: Wikipedia



The Apache Zookeeper Tool is used in HA setups to maintain configuration information for distributed services.