Solid Queue Coder

Overview

Solid Queue is Rails 8's default job backend—a database-backed Active Job adapter that eliminates the need for Redis. Jobs are stored in your database with ACID guarantees.

Configuration

Database Setup

config/database.yml

production: primary: <<: *default url: <%= ENV["DATABASE_URL"] %> queue: <<: *default url: <%= ENV["QUEUE_DATABASE_URL"] %> migrations_paths: db/queue_migrate

Queue Configuration

config/solid_queue.yml

production: dispatchers: - polling_interval: 1 batch_size: 500

workers: - queues: [critical, default] threads: 5 processes: 2 polling_interval: 0.1 - queues: [low_priority] threads: 2 processes: 1 polling_interval: 1

Application Configuration

config/application.rb

config.active_job.queue_adapter = :solid_queue

config/environments/production.rb

config.solid_queue.connects_to = { database: { writing: :queue } }

Queue Design

Priority Strategy

class CriticalNotificationJob < ApplicationJob queue_as :critical queue_with_priority 1 # Lower = higher priority end

class ReportGenerationJob < ApplicationJob queue_as :low_priority queue_with_priority 50 end

Concurrency Control

class ProcessUserDataJob < ApplicationJob limits_concurrency key: ->(user_id) { user_id } end

class SyncContactJob < ApplicationJob limits_concurrency key: ->(contact) { contact.id }, duration: 15.minutes, group: "ContactOperations" end

Recurring Jobs

config/solid_queue.yml

recurring: cleanup_old_records: class: CleanupJob schedule: every day at 3am queue: low_priority

sync_external_data: class: SyncExternalDataJob schedule: every 15 minutes queue: default

Deployment

Procfile

web: bundle exec puma -C config/puma.rb worker: bundle exec rake solid_queue:start

Docker Compose

services: web: command: bundle exec puma -C config/puma.rb worker: command: bundle exec rake solid_queue:start

Error Handling

class ExternalApiJob < ApplicationJob retry_on Net::OpenTimeout, wait: :polynomially_longer, attempts: 5 discard_on ActiveJob::DeserializationError

rescue_from StandardError do |exception| if executions >= 5 FailedJob.create!(job_class: self.class.name, error_message: exception.message) else raise exception end end end

Database Maintenance

namespace :queue do task vacuum: :environment do ActiveRecord::Base.connected_to(database: :queue) do %w[solid_queue_ready_executions solid_queue_claimed_executions].each do |table| ActiveRecord::Base.connection.execute("VACUUM ANALYZE #{table}") end end end end

Solid Queue vs Sidekiq

Feature Solid Queue Sidekiq

Infrastructure Database only Requires Redis

ACID guarantees Yes No

Transactional enqueue Yes No

Concurrency control Built-in Requires sidekiq-unique-jobs

Anti-Patterns

Anti-Pattern Problem Solution

Wildcard queue * in prod Unpredictable priority Specify queue order

Single database Contention with app Separate queue database

Too many threads Database exhaustion Match pool size

Output Format

When configuring Solid Queue, provide:

• Database Setup - Multi-database configuration

• Queue Config - solid_queue.yml settings

• Worker Setup - Procfile/Docker configuration

• Jobs - Example job classes with error handling