PostgreSQL Setup for taskqueue

Overview

The taskqueue package uses PostgreSQL to manage tasks, projects, and workers. This vignette shows how to install and configure PostgreSQL on Ubuntu for HPC environments.

PostgreSQL should be installed on a server that all worker nodes can access.

Why PostgreSQL?

PostgreSQL is chosen for taskqueue because:

• Concurrent Access: Handles large numbers of concurrent requests from multiple workers
• ACID Compliance: Ensures data integrity for task status updates
• Reliability: Proven track record for production workloads
• Performance: Efficient handling of read/write operations
• Open Source: Free and widely supported

Installation on Ubuntu

# Update and install PostgreSQL
sudo apt update
sudo apt install postgresql postgresql-contrib

# Start PostgreSQL
sudo systemctl start postgresql
sudo systemctl enable postgresql

Create Database and User

# Switch to postgres user and create database
sudo -u postgres psql

# Run these commands in the PostgreSQL prompt:
CREATE USER taskqueue_user WITH PASSWORD 'your_password';
CREATE DATABASE taskqueue_db OWNER taskqueue_user;
GRANT ALL PRIVILEGES ON DATABASE taskqueue_db TO taskqueue_user;
\q

Configure Remote Access

Allow worker nodes to connect to PostgreSQL.

# Edit configuration file (adjust version number if needed)
sudo nano /etc/postgresql/14/main/postgresql.conf

# Find and change:
listen_addresses = '*'

# Edit authentication file
sudo nano /etc/postgresql/14/main/pg_hba.conf

# Add this line:
# For specific HPC network (recommended):
host    taskqueue_db    taskqueue_user    10.0.0.0/8        md5
# Or for all IPs (less secure):
host    taskqueue_db    taskqueue_user    0.0.0.0/0         md5

sudo systemctl restart postgresql

# Allow PostgreSQL port from HPC network
sudo ufw allow from 10.0.0.0/8 to any port 5432
# Or allow from all IPs (less secure):
sudo ufw allow 5432/tcp

R Configuration

On all machines (daily working machines, login nodes and compute nodes), add these environment variables to ~/.Renviron:

PGHOST=your.database.server.com
PGPORT=5432
PGUSER=taskqueue_user
PGPASSWORD=your_password
PGDATABASE=taskqueue_db

Edit .Renviron:

nano ~/.Renviron
# Add the variables above, then save and exit

Restart R after editing .Renviron.

Install R Packages

# install from CRAN
install.packages("taskqueue")

# or install the latest development version from GitHub
remotes::install_github("byzheng/taskqueue")

Test Connection

library(taskqueue)
db_connect()

Initialize taskqueue

library(taskqueue)

# Create required tables
db_init()

Security Notes

• Use strong passwords
• Restrict IP ranges in pg_hba.conf to your HPC network only
• Protect .Renviron: chmod 600 ~/.Renviron

Clean Database

If needed, remove all taskqueue data:

library(taskqueue)
db_clean()  # Removes all tables

The package will recreate tables automatically when needed.