Fine-Tuning Tomcat 8 JDBC Connection Pool

DataOps Labs

I'm Ayyanar Jeyakrishnan ; aka AJ. With over 21 years in IT, I'm a passionate Multi-Cloud Architect specialising in crafting scalable and efficient cloud solutions. I've successfully designed and implemented multi-cloud architectures for diverse organisations, harnessing AWS, Azure, and GCP. My track record includes delivering Machine Learning and Data Platform projects with a focus on high availability, security, and scalability. I'm a proponent of DevOps and MLOps methodologies, accelerating development and deployment. I actively engage with the tech community, sharing knowledge in sessions, conferences, and mentoring programs. Constantly learning and pursuing certifications, I provide cutting-edge solutions to drive success in the evolving cloud and AI/ML landscape.

Stay updated on the latest in AI/ML, Cloud, DevOps, MLOps, Generative AI and cutting-edge techniques with this continuous learning free newsletters.

🔧 1. Right-Size `maxActive`

Description: Maximum number of active connections in the pool.

🛑 Issue: Too low = connection starvation. Too high = DB overload.

✅ Recommendation:

maxActive="100"

📎 Tomcat 8 Docs - maxActive

⏱ 2. Set a Sensible `maxWait`

Description: How long (in ms) to wait for a connection before throwing an exception.

🛑 Issue: Low value = frequent timeouts under load.

✅ Recommendation:

maxWait="10000"

📎 Tomcat 8 Docs - maxWait

✅ 3. Avoid Stale Connections with `validationQuery`, `testOnBorrow`, and `validationInterval`

Description: Checks that a DB connection is valid before returning it to the app.

🛑 Issue: Stale connections lead to failed transactions.

✅ Recommendation:

testOnBorrow="true"
validationQuery="SELECT 1"
validationInterval="30000"

📎 Tomcat 8 Docs - validationQuery & testOnBorrow

💤 4. Manage Idle Connections with `minIdle`, `maxIdle`, `timeBetweenEvictionRunsMillis`, `minEvictableIdleTimeMillis`

Description: Controls idle connection cleanup to avoid leaks and unnecessary DB usage.

✅ Recommendation:

minIdle="10"
maxIdle="30"
timeBetweenEvictionRunsMillis="30000"
minEvictableIdleTimeMillis="60000"

📎 Tomcat 8 Docs - Idle Connection Settings

Fine-Tuning Tomcat 8 JDBC Connection Pool

Comments

More from this blog

Goal Is NOT More AI: Building AI-Native Engineering Organizations for Sustainable Productivity

LiveKB: Your Procedures Are Lying to Your People — The Knowledge Gap Nobody Measures

LiveKB: Production Architecture with Strands Agents, Bedrock, and AgentCore on AWS

The Document AI Stack That Actually Powers Production RAG: Layout Models, Chunking Ontologies, and the Preprocessing Truth Nobody Talks About

The Agentic Trifecta

🔧 1. Right-Size `maxActive`

✅ Recommendation:

⏱ 2. Set a Sensible `maxWait`

✅ Recommendation:

✅ 3. Avoid Stale Connections with `validationQuery`, `testOnBorrow`, and `validationInterval`

✅ Recommendation:

💤 4. Manage Idle Connections with `minIdle`, `maxIdle`, `timeBetweenEvictionRunsMillis`, `minEvictableIdleTimeMillis`

✅ Recommendation:

Command Palette

Comments

More from this blog

🔧 1. Right-Size maxActive

✅ Recommendation:

⏱ 2. Set a Sensible maxWait

✅ Recommendation:

✅ 3. Avoid Stale Connections with validationQuery, testOnBorrow, and validationInterval

✅ Recommendation:

💤 4. Manage Idle Connections with minIdle, maxIdle, timeBetweenEvictionRunsMillis, minEvictableIdleTimeMillis

✅ Recommendation:

🔧 1. Right-Size `maxActive`

⏱ 2. Set a Sensible `maxWait`

✅ 3. Avoid Stale Connections with `validationQuery`, `testOnBorrow`, and `validationInterval`

💤 4. Manage Idle Connections with `minIdle`, `maxIdle`, `timeBetweenEvictionRunsMillis`, `minEvictableIdleTimeMillis`