NuoDB components, their relationships, and rules of use.


What are the basic components of NuoDB, their relationships, and rules of use?



TRANSACTION ENGINE (TE) - a process that provides application access to a single NuoDB database by processing SQL commands, caching data, and coordinating transactions with other TEs and storage managers.

STORAGE MANAGER (SM) - a process that provides durability of the data that it handles (for example by writing to disk).

ARCHIVE - the persistent stored copy of the database on disk.  Every SM serves an archive in a one to one relationship.

ADMIN PROCESS - Manages SQL application access to transaction engines. The admin process is independent of any particular database in the NuoDB system. A domain comprises one or more admin processes.

DOMAIN - A domain is a set of hosts/containers provisioned to run NuoDB.

  • In physical or virtualization deployments each host/VM runs a NuoDB admin process. In Kubernetes deployments, NuoDB admin processes are started in different containers in the same namespace.
  • A domain is a secure environment for deploying and managing NuoDB distributed Databases. A domain can contain one or more databases and each database can run on one or more hosts.
  • Each physical machine (host) in the domain runs one admin process that manages the databases on that host. In Kubernetes deployments, the admin process can manage one or more externally started engine processes.
  • NuoDB’s architecture includes a management tier including NuoDB Admin processes which are referred to as peers.
  • A domain is a management boundary. It defines the resources available to run databases and the set of users with permission to manage those resources.
  • A system administrator views a domain as a single, logical point of management. Each peer provides a place to connect to the domain, manage and monitor databases, and ensure that NuoDB is running as expected.

Domain administration includes:

  • Provisioning a set of hosts where NuoDB runs. These hosts could be in cloud environments such as AWS EC2 and/or on machines in a data center.
  • Installing NuoDB on the provisioned hosts, see Installing NuoDB.
  • Configuring admin processes to form a peer network of the hosts where NuoDB is installed.

Some basics:

A. In physical deployments, each server on which you wish to run a Transaction Engine (TE) or Storage Manager (SM) must first be running ONE NuoDB admin process.

B. At least one of the admin processes in a domain will be elected the leader by the Raft consensus algorithm.

C. There may be any number of TEs running on a single machine or across a cluster.

D. There may be any number of SMs running on a single machine or across a cluster.

E. Each SM stores a complete copy of all data in your database in case storage groups are not used. A 2nd or 3rd SM is only needed for redundancy.


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