/basic-acd

Implementation of a contact center ACD in Redis Enterprise

Primary LanguagePythonOtherNOASSERTION

Redis Basic ACD

Contents

  1. Summary
  2. Architecture
  3. Methodology
  4. Features
  5. Prerequisites
  6. Installation
  7. Usage

Summary

This is a demo of a contact center ACD application implemented with Redis. Multiple skills and multi-skilled agents are supported. Longest Available Agent (LAA) targeting is performed.

Architecture

architecture

Methodology

Redis Data Structures

Contacts

Contacts are implemented as Redis JSON objects. Each contact contains a JSON array of requisite skills.

Agents

Agents are implemented as Redis JSON objects. Each agent has meta data (first and last names) and a JSON array of their skills.

Skills/Available Agents

Availability queues for each skill are implemented as Redis Sorted Sets. The members of the set are available agents. Their associated scores are a timestamp (ms) signifying when they became available. This allows for LAA selection.

Queue

A universal queue is implemented as a Redis Sorted Set. The members of the set are the keys to the contacts and their associated scores are timestamps of their entry time to queue. This allows for multi-skill selection and FIFO handling.

Agent Targeting

  • Available agents are placed into availability sorted sets per skill with a timestamp as their score.
  • Contacts are placed into queue implemented as a sorted set with a timestamp as their score.
  • Contacts are taken off of queue in a FIFO manner with BZPOPMIN
  • Agents are targeted via ZINTER of the skill availability sets. The Agent with the lowest score (oldest timestamp) and possessing all the requisite skills for a contact gets selected.

Load Balancing

HAProxy is used for load balancing all client connections.

High Availability

Two HAProxy instances are deployed in a HA configuration via keepalived (VRRP). The VIP those instances share is 192.168.20.100.

Rest API Server Connections - Port 8000

  • HTTP round-robin load balancing across 2 servers
  • Dynamic scaling/Docker replica support via DNS and server-template

Redis Admin Console Connections - Port 8443

  • HTTP least connection load balancing across 3 servers
  • TLS back-to-back sessions. A self-signed certificate is generated by the start.sh script. That cert is used for the front-end. The default Redis-generated cert is used on the back-end.
  • 'Sticky' sessions via server cookie

Redis REST API Connections - Port 9443

  • TCP round-robin load balancing across 3 servers
  • TLS pass-thru

Redis Database Connections - Port 12000

  • TCP round-robin load balancing across 3 servers
  • Layer 7 health check via authenticated client connection w/Redis PING.

Features

  • Redis Enterprise - 3 nodes with 1 database of 2 shards
  • Python REST API server (FastAPI) for proxying client operations into Redis
  • Redis-py async client for all ACD operations
  • Redis-py dispatcher application for monitoring the ACD queue and assigning agents to contacts
  • Python simulator application for generating contacts into the ACD via REST API operations
  • HAProxy Load Balancing of all Redis and HTTP connections
  • VRRP redundancy of HAProxy instances via keepalived

Prerequisites

  • Docker
  • Docker Compose
  • openssl
  • python3

Installation 

git clone https://github.com/Redislabs-Solution-Architects/basic-acd.git && cd basic-acd
pip install -r requirements.txt

Usage

Environment Start Up

start.sh

Simulator Start Up

cd ./src && python3 simulator.py

Environment Shut Down

stop.sh