The Gremlin graph traversal machine and language (invited talk)

Abstract

Gremlin is a graph traversal machine and language designed, developed, and distributed by the Apache TinkerPop project. Gremlin, as a graph traversal machine, is composed of three interacting components: a graph G, a traversal Ψ, and a set of traversers T . The traversers move about the graph according to the instructions specified in the traversal, where the result of the computation is the ultimate locations of all halted traversers. A Gremlin machine can be executed over any supporting graph computing system such as an OLTP graph database and/or an OLAP graph processor. Gremlin, as a graph traversal language, is a functional language implemented in the user's native programming language and is used to define the Ψ of a Gremlin machine. This article provides a mathematical description of Gremlin and details its automaton and functional properties. These properties enable Gremlin to naturally support imperative and declarative querying, host language agnosticism, user-defined domain specific languages, an extensible compiler/optimizer, single-and multi-machine execution models, hybrid depth-and breadth-first evaluation, as well as the existence of a Universal Gremlin Machine and its respective entailments.

Indoor Navigation for Motion Disabled Persons in Medical Facilities

“…It does not return what the path is nor the length of the shortest path -only whether there is such a path. By probing against different path lengths, this limitation can be overcome by a query similar to the following, which returns the shortest route (routes with the least steps) between <room1> and <room2> (with maximum length of three steps for brevity): Gremlin [16], as a graph traversal language, is a functional language. The purpose of the language is to enable a human user to easily define a traversal, which is a tree of functions called steps, and thus, program a Gremlin machine.…”

Onyx: A new Canvas‐based tool for visualizing biomedical and health ontologies

“…Communication between Web applications and the Cayley Graph Database is implemented via Gremlin queries. Gremlin (TinkerPop, first release: ; Rodriguez, ) is a domain specific language for traversing property graphs.…”

Model-Driven Engineering of an OpenCypher Engine: Using Graph Queries to Compile Graph Queries

“…The TinkerPop framework aims to define a standard data model for property graphs. For graph queries, it provides the Gremlin Structure API, a low-level programming interface and the Gremlin language, a high-level imperative graph traversal language [31]. The latter is implemented as a Groovy DSL [20].…”