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Building a High-Availability Distributed SQLite Cluster for Microservices Using rqlite on 3 Free ARM VPS Instances

June 4, 2026

Introduction: The Microservices Database Dilemma

In contemporary software engineering, microservices architectures demand storage solutions that balance decentralization, low latency, and operational simplicity. While traditional relational database management systems (RDBMS) like PostgreSQL or MySQL are powerful, managing their replication, clustering, and resource consumption can introduce significant operational overhead. On the other end of the spectrum, SQLite is celebrated for its lightweight, zero-configuration, and high-performance single-file nature, yet it inherently lacks native network access and high availability (HA).

This is where rqlite enters the paradigm. By combining the speed of SQLite with the robust Raft consensus algorithm, rqlite transforms an embedded database into a fully distributed, fault-tolerant, and replicating relational database system. In this technical guide, we will explore how to architect, deploy, and optimize a 3-node rqlite cluster using free-tier ARM-based Virtual Private Servers (VPS), creating a production-grade database backend for microservices without incurring infrastructure costs.

Understanding the Core Architecture

Why rqlite for Microservices?

Microservices often require isolated, service-specific data stores. Deploying heavy database instances for every small service escalates cloud expenditure and resource utilization. rqlite addresses this challenge by providing a lightweight, network-accessible SQL database. Key benefits include:

  • Strong Consistency: Utilizing the Raft algorithm ensures that all cluster nodes agree on data changes, preventing split-brain scenarios.
  • Fault Tolerance: A 3-node cluster can tolerate the failure of a single node without interrupting service or losing data integrity.
  • Minimal Resource Footprint: Running efficiently on ARM architectures, rqlite consumes a fraction of the memory and CPU required by traditional distributed databases.

The Power of ARM VPS Free Tiers

Major cloud providers now offer generous free-tier compute options powered by ARM processors. These ARM instances provide exceptional performance-per-watt and processing capabilities, making them the ideal deployment target for budget-conscious engineering teams looking to build robust proof-of-concepts or staging environments that mimic production resilience.

Prerequisites and Environment Setup

Before initiating the cluster deployment, ensure you have provisioned three distinct ARM-based VPS instances running a modern Linux distribution (e.g., Ubuntu 22.04 LTS or newer). For the sake of clarity, we will define our node topology as follows:

  • Node 1 (Leader Candidate): IP 10.0.0.1
  • Node 2 (Follower Candidate): IP 10.0.0.2
  • Node 3 (Follower Candidate): IP 10.0.0.3

Network and Firewall Configuration

rqlite requires specific ports to be open for inter-node communication (Raft consensus) and client API interactions. By default, rqlite utilizes port 4001 for both HTTP API and Raft communication, though these can be separated. Execute the following commands on each node to configure the firewall:

sudo ufw allow 4001/tcp
sudo ufw allow 4002/tcp
sudo ufw enable
Security Note: In a production environment, restrict access to port 4002 (or internal cluster ports) explicitly to the IP addresses of your cluster nodes to prevent unauthorized node-joining attempts.

Step-by-Step Cluster Deployment

Step 1: Installing rqlite on ARM Architecture

Download the pre-compiled binary optimized for ARM64 architectures. Execute these commands on all three nodes:

wget [https://github.com/rqlite/rqlite/releases/download/v8.0.0/rqlite-v8.0.0-linux-arm64.tar.gz](https://github.com/rqlite/rqlite/releases/download/v8.0.0/rqlite-v8.0.0-linux-arm64.tar.gz)
tar -xvf rqlite-v8.0.0-linux-arm64.tar.gz
sudo mv rqlite-v8.0.0-linux-arm64/rqlited /usr/local/bin/
sudo mv rqlite-v8.0.0-linux-arm64/rqlite /usr/local/bin/

Step 2: Bootstrapping the First Node (The Cluster Seed)

On Node 1, initialize the cluster. This node acts as the initial leader until other nodes join and elect a formal leader via the Raft consensus.

rqlited -node-id node1 -http-addr 10.0.0.1:4001 -raft-addr 10.0.0.1:4002 ~/node1_data

Step 3: Joining the Remaining Nodes

Once Node 1 is online, execute the startup command on Node 2 and Node 3, instructing them to join the existing cluster via Node 1's Raft address.

On Node 2:

rqlited -node-id node2 -http-addr 10.0.0.2:4001 -raft-addr 10.0.0.2:4002 -join [http://10.0.0.1:4001](http://10.0.0.1:4001) ~/node2_data

On Node 3:

rqlited -node-id node3 -http-addr 10.0.0.3:4001 -raft-addr 10.0.0.3:4002 -join [http://10.0.0.1:4001](http://10.0.0.1:4001) ~/node3_data

Verifying Cluster Health and Consensus

To ensure that the cluster has formed successfully and that consensus is active, use the rqlite CLI tool from any node to query the system status:

rqlite -h 10.0.0.1:4001
10.0.0.1:4001> .status

The output will yield critical diagnostics. Look specifically for the store section, ensuring that num_peers reads 2 (indicating 3 total nodes) and the leader field correctly identifies the active coordinator. This architecture guarantees strict serializability for write operations, keeping your microservices data highly synchronized.

Integrating rqlite with Microservices

Microservices interact with rqlite via standard HTTP REST endpoints or through language-specific client libraries (available for Go, Python, Node.js, and Java). Below is an architectural blueprint of how a microservice performs safe execution loops:

  1. Write Operations: Must always be directed to the leader node. If sent to a follower, rqlite can be configured to automatically forward the write to the leader.
  2. Read Operations: Can be distributed across follower nodes using the level=none or level=weak query parameters to achieve ultra-low latency reads, or directed to the leader with level=strong to guarantee read-your-writes consistency.

Conclusion and Best Practices

Deploying rqlite on free ARM VPS instances delivers a resilient, high-performance database tier tailored perfectly for microservices. By migrating the operational complexity away from resource-heavy RDBMS solutions, engineering teams can maintain agility and zero-cost infrastructure overhead. For long-term production sustainability, remember to implement automated backups of the rqlite data directories to external object storage, mandate TLS encryption for all inter-node traffic, and establish strict monitoring over disk I/O performance across your ARM instances.