How We Reduced API Latency by 40% Using Spring Boot Virtual Threads Associative

The Challenge of Blocking I/O in High-Traffic APIs

At Associative, transforming visionary ideas into scalable digital realities is what we do best. Recently, while scaling a complex web application for high-frequency data processing, we hit a common bottleneck: the traditional thread-per-request model.

In standard Java applications, every incoming request consumes a dedicated OS thread. When that request involves blocking I/O operations—like querying our PostgreSQL databases or calling external third-party APIs—the thread sits idle, waiting. Under heavy load, thread pools exhaust quickly, leading to increased response times, high memory consumption, and degraded user experiences. We needed a solution that aligned with our commitment to high-performance, scalable server-side logic.

The Solution: Embracing Java Virtual Threads

To solve this, our backend experts turned to Project Loom’s most anticipated feature: Virtual Threads, fully supported in Java 21 and Spring Boot 3.2+.

Unlike traditional platform threads tied 1:1 to heavy OS threads, virtual threads are lightweight and managed by the JVM. Millions of virtual threads can run concurrently without exhausting system resources. When a virtual thread encounters a blocking operation, the JVM simply unmounts it, allowing the underlying OS thread to process other requests.

How We Implemented the Change

Our team of dedicated IT professionals followed a streamlined process to integrate virtual threads into the existing architecture:

Environment Upgrade: We migrated the application to Java 21 and upgraded the framework to Spring Boot 3.2+, ensuring compatibility across our Docker and Kubernetes CI/CD pipelines.
Enabling Virtual Threads: The transition was remarkably seamless. We enabled virtual threads at the application level by simply setting spring.threads.virtual.enabled=true in our configuration.
Refactoring Thread Pools: We replaced custom ThreadPoolTaskExecutor configurations with the new virtual thread task executors, allowing Spring’s embedded Tomcat server to handle incoming requests natively using virtual threads.
Database and External API Tuning: Leveraging our proficiency in SQL (PostgreSQL) and NoSQL databases, we ensured our connection pools were properly tuned to handle the massive increase in concurrent requests without overwhelming the database connections.

The Results: A 40% Reduction in API Latency

The performance gains were immediate and measurable:

40% Latency Reduction: By eliminating the overhead of OS thread context switching and thread blocking, our p95 response times dropped significantly.
Increased Throughput: The system could handle a drastically higher number of concurrent users without needing additional cloud infrastructure scaling on AWS.
Lower Memory Footprint: The lightweight nature of virtual threads reduced the overall RAM consumption of the application, driving cost efficiency.

Partner with Associative for Scalable Back-End Solutions

This case study is just one example of how Associative guides businesses through the complexities of the digital landscape. Established on February 1, 2021, and headquartered in Pune, Maharashtra, we offer a one-stop-shop for businesses seeking to innovate.

Our expertise spans the full product lifecycle:

Advanced Back-End Development: Node.js, Python (Django, FastAPI), PHP (Laravel), Ruby on Rails, and Java (Spring Boot, Jakarta EE).
Front-End & CMS Mastery: React, Angular, Next.js, Headless CMS (Strapi – Official Reseller Partner), and Adobe Commerce (Adobe Silver Solution Partner).
Cloud & DevOps: Expert management of AWS, Google Cloud, and Azure using Docker, Kubernetes, and Terraform.

Our Commitment to You

We operate with unyielding transparency, open communication, and strict regulatory compliance (registered with ROF, Pune).

Total Confidentiality: We adhere to rigorous NDAs. We do not maintain a public portfolio, ensuring your intellectual property is protected.
100% IP Ownership: Upon project completion and final payment, you receive full ownership of the source code.
Transparent Billing: We operate Monday through Saturday on a time-and-materials basis. Invoices are submitted daily, weekly, or via milestones, so you only pay for the work performed.
Flexible Engagement: Choose variable engagement models from 3 to 9 hours per day.

Bring Your Vision to Life

Whether you need to optimize an existing architecture, build an AI-driven platform like our R&D project NexusReal, or develop a high-frequency trading bot, our developers are ready to help from our secure offices.

Contact Us Today:

WhatsApp: +91 9028850524
Email: info@associative.in
Website: https://associative.in
Office Hours: 10:00 AM to 8:00 PM
Address: Khandve Complex, Yojana Nagar, Lohegaon – Wagholi Road, Lohegaon, Pune, Maharashtra, India – 411047

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