Glossary

An entity that can be used to describe an action on an object and represents a launch of an Ansible playbook with certain parameters defined by a bundle or user under certain conditions.

Group of hosts that is configured for an object (cluster, service, or component) to run actions allowed for the specified object separately for hosts included into that group.

A directory service for Windows Server family operating systems. It was initially created as an LDAP-compatible implementation of a directory service. However, starting with Windows Server 2008, it includes integration capabilities with other authorization services, performing an integrating and unifying role for them.

Application programming interface — a set of ready-made classes, procedures, functions, structures, and constants provided by an application (library, service) or operating system for use in external software products.

An object which is a .tar file with prepared Ansible playbooks and configuration files and used to install and deploy other objects.

A set of services running on the set of hosts.

Command-line interface — a kind of text user interface (TUI) where users give instructions to a computer by typing text strings (commands) from the keyboard. Other names are console and terminal.

A part of the service.

A notification of users that can be blocking (red) or non-blocking (yellow) with the obligatory indication of the reason for the notification, for example, unfilled mandatory parameter fields in the object configuration.

An object configuration parameters and their values that are set for a particular host or a group of hosts and different from the parameters of the object general configuration.

A working server, which is a program code that typically runs on a separate HDFS instance. It is responsible for file-level operations (such as writing and reading data) and executing commands received from a NameNode (create, delete, replicate blocks, etc.). Besides that, a DataNode usually performs:

Domain name system — a distributed and hierarchical system used to identify computers, domains, services, and other resources accessible through the Internet or other network protocols. It is most often used to get an IP address by a host name (computer or device), obtain information about mail routing and/or service nodes for protocols in a domain.

A software package designed to monitor and filter network traffic.

A free and open-source identity management system for Linux/UNIX networked environments. It is based on Fedora Linux, 389 Directory Server, MIT Kerberos, NTP, DNS, the DogTag certificate system, SSSD, and other free/open-source components. FreeIPA is designed with an intent to provide the same services as Active Directory.

Fully qualified domain name — a domain name that has no ambiguities in its definition. Includes the names of all the parent domains in the DNS hierarchy.

Hadoop Distributed File System — a file system designed to store large data distributed block-by-block across cluster nodes. All blocks in HDFS (except for the last file block) have the same size, and each block can be hosted on multiple nodes. The block size and replication factor (the number of nodes to which each block should be replicated) are defined in the file-level settings. Due to replication, the distributed system is resistant to failures of individual nodes.

A representation of an actual hardware or virtual host accessed via the SSH protocol.

An object that is able to produce a host.

A transfer of the specific service settings to a cluster or service from other clusters or services.

A single copy of any software running on a single physical or virtual server.

Set of hosts for the Ansible inventory intended for use in playbooks by the bundle developer.

Internet protocol address — a unique network address of a node in a computer network built on the IP protocol stack.

A type of action that starts a single script.

Lightweight Directory Access Protocol — a simple protocol that uses TCP/IP and allows authentication, search and compare operations, as well as operations for adding, modifying, or deleting records.

A certain state of a service, host, or component which:

An allocation of components among hosts.

Structured service information about the used data. Contains characteristics useful for identification, search, evaluation, and management.

A lead server that manages the HDFS file system metadata. It is a program code that typically runs on a separate HDFS instance machine and is responsible for file operations (such as opening and closing files, creating and deleting directories, etc.). Besides that, NameNode is responsible for:

A prototype instance that appears when creating a cluster, service, component, etc.

A basic element of the role model.

A set of three elements (user group, role, and object, to which the role permissions are applied) which ensures that the user can access only those actions and objects that are included in that policy.

An open-source relational database management system.

Configuration parameters and their values with which you can configure the objects.

A description of a single object which is a template with metadata for the object the bundle will contain.

A set of permissions for operations with various objects that is assigned to a user group via policy.

Superuser — a special account in Unix-like systems, the owner of which has the right to perform any and all operations.

A set of instructions executed by the system. The difference between programs and scripts is quite blurry: a script is a program dealing with ready-made software components.

A software that functions on hosts and is a single entity or a logical entity that consists of several components.

A lightweight, embedded, and open-source relational database management system.

Secure shell — an application-level network protocol that allows remote control of the operating system and tunneling of TCP connections (for example, to transfer files). It is similar in functionality to the Telnet and rlogin protocols, but, unlike them, it encrypts all traffic, including transmitted passwords. SSH allows you to choose different encryption algorithms. SSH clients and SSH servers are available for most network operating systems.

Secure sockets layer — a cryptographic protocol that implies secure communication. It uses asymmetric cryptography to authenticate exchange keys, symmetric encryption to maintain confidentiality, and message authentication codes to ensure message integrity.

Switch user — a command in Unix-like operating systems that allows a user to log in under a different name without terminating the current session. It is usually used by the superuser for temporary login to perform administrative work.

Substitute user and do — a program for system administration of Unix-like operating systems that allows delegating certain privileged resources to users with the maintenance of the work protocol. The main idea is to give users as few rights as possible, while enough to solve the tasks.

A type of action that is a chain of jobs.

An operation available from an object (cluster or hostprovider) certain state that updates object metadata and moves it to a different state.

Uniform resource identifier — a unified sequence of characters that identifies an abstract or physical resource.

Uniform resource locator — a uniform identifier for the location of an abstract or physical resource.

ZKFailoverController — a ZooKeeper client which monitors and manages the NameNode state.

An open-source service for synchronization and coordination of distributed systems.