Scripting Redict with Lua on Redict

Executing Lua scripts

Mon, 01 Jan 0001 00:00:00 +0000

Executing Lua scripts in Redict #

Redict lets users upload and execute Lua scripts on the server. Scripts can employ programmatic control structures and use most of the commands while executing to access the database. Because scripts execute in the server, reading and writing data from scripts is very efficient.

Redict guarantees the script’s atomic execution. While executing the script, all server activities are blocked during its entire runtime. These semantics mean that all of the script’s effects either have yet to happen or had already happened.

Using Lua functions

Mon, 01 Jan 0001 00:00:00 +0000

Redict Functions #

Redict Functions is an API for managing code to be executed on the server. They are an evolutionary step from ephemeral scripting.

Functions provide the same core functionality as scripts but are first-class software artifacts of the database. Redict manages functions as an integral part of the database and ensures their availability via data persistence and replication. Because functions are part of the database and therefore declared before use, applications aren’t required to load them during runtime nor risk aborted transactions. An application that uses functions depends only on their APIs rather than on the embedded script logic in the database.

Debugging Lua scripts

Mon, 01 Jan 0001 00:00:00 +0000

Debugging Lua scripts in Redict #

Redict includes a complete Lua debugger, that can be used in order to make the task of writing complex Redict scripts much simpler.

Note: Please make sure to avoid debugging Lua scripts using your Redict production server. Use a development server instead. Also note that using the synchronous debugging mode (which is NOT the default) results in the Redict server blocking for all the time the debugging session lasts.

API reference

Mon, 01 Jan 0001 00:00:00 +0000

Redict Lua API reference #

Redict includes an embedded Lua 5.1 interpreter. The interpreter runs user-defined ephemeral scripts and functions. Scripts run in a sandboxed context and can only access specific Lua packages. This page describes the packages and APIs available inside the execution’s context.

Sandbox context #

The sandboxed Lua context attempts to prevent accidental misuse and reduce potential threats from the server’s environment.

Scripts should never try to access the Redict server’s underlying host systems. That includes the file system, network, and any other attempt to perform a system call other than those supported by the API.