Vlad Mihalcea

The simple scalability equation

Are you struggling with performance issues in your Spring, Jakarta EE, or Java EE application?

Imagine having a tool that could automatically detect performance issues in your JPA and Hibernate data access layer long before pushing a problematic change into production!

With the widespread adoption of AI agents generating code in a heartbeat, having such a tool that can watch your back and prevent performance issues during development, long before they affect production systems, can save your company a lot of money and make you a hero!

Hypersistence Optimizer is that tool, and it works with Spring Boot, Spring Framework, Jakarta EE, Java EE, Quarkus, Micronaut, or Play Framework.

So, rather than allowing performance issues to annoy your customers, you are better off preventing those issues using Hypersistence Optimizer and enjoying spending your time on the things that you love!

Queuing Theory

The queueing theory allows us to predict queue lengths and waiting times, which is of paramount importance for capacity planning. For an architect, this is a very handy tool since queues are not just the appanage of messaging systems.

To avoid system over loading we use throttling. Whenever the number of incoming requests surpasses the available resources, we basically have two options:

  • discarding all overflowing traffic, therefore decreasing availability
  • queuing requests and wait (for as long as a time out threshold) for busy resources to become available

This behavior applies to thread-per-request web servers, batch processors or connection pools.

What’s in it for us?

Agner Krarup Erlang is the father of queuing theory and traffic engineering, being the first to postulate the mathematical models required to provisioning telecommunication networks.

Erlang formulas are modeled for M/M/k queue models, meaning the system is characterized by:

The Erlang formulas give us the servicing probability for:

This is not strictly applicable to thread pools, as requests are not fairly serviced and servicing times not always follow an exponential distribution.

A general purpose formula, applicable to any stable system (a system where the arrival rate is not greater than the departure rate) is Little’s Law.

Read More

Time to break free from the SQL-92 mindset

Are you struggling with performance issues in your Spring, Jakarta EE, or Java EE application?

Imagine having a tool that could automatically detect performance issues in your JPA and Hibernate data access layer long before pushing a problematic change into production!

With the widespread adoption of AI agents generating code in a heartbeat, having such a tool that can watch your back and prevent performance issues during development, long before they affect production systems, can save your company a lot of money and make you a hero!

Hypersistence Optimizer is that tool, and it works with Spring Boot, Spring Framework, Jakarta EE, Java EE, Quarkus, Micronaut, or Play Framework.

So, rather than allowing performance issues to annoy your customers, you are better off preventing those issues using Hypersistence Optimizer and enjoying spending your time on the things that you love!

Are you stuck in the 90s?

If you are only using the SQL-92 language reference, then you are overlooking so many great features like:

Some test data

In my previous article I imported some CSV Dropwizard metrics into PostgreSQL for further analysis.

Read More

How to import CSV data into PostgreSQL

Are you struggling with performance issues in your Spring, Jakarta EE, or Java EE application?

Imagine having a tool that could automatically detect performance issues in your JPA and Hibernate data access layer long before pushing a problematic change into production!

With the widespread adoption of AI agents generating code in a heartbeat, having such a tool that can watch your back and prevent performance issues during development, long before they affect production systems, can save your company a lot of money and make you a hero!

Hypersistence Optimizer is that tool, and it works with Spring Boot, Spring Framework, Jakarta EE, Java EE, Quarkus, Micronaut, or Play Framework.

So, rather than allowing performance issues to annoy your customers, you are better off preventing those issues using Hypersistence Optimizer and enjoying spending your time on the things that you love!

Introduction

Many database servers support CSV data transfers and this post will show one way you can import CSV files to PostgreSQL.

SQL aggregation rocks!

My previous post demonstrated FlexyPool metrics capabilities and all connection related statistics were exported in CSV format.

When it comes to aggregation tabular data SQL is at its best. If your database engine supports SQL:2003 windows functions you should definitely make use of this great feature.

Read More

Professional connection pool sizing with FlexyPool

Are you struggling with performance issues in your Spring, Jakarta EE, or Java EE application?

Imagine having a tool that could automatically detect performance issues in your JPA and Hibernate data access layer long before pushing a problematic change into production!

With the widespread adoption of AI agents generating code in a heartbeat, having such a tool that can watch your back and prevent performance issues during development, long before they affect production systems, can save your company a lot of money and make you a hero!

Hypersistence Optimizer is that tool, and it works with Spring Boot, Spring Framework, Jakarta EE, Java EE, Quarkus, Micronaut, or Play Framework.

So, rather than allowing performance issues to annoy your customers, you are better off preventing those issues using Hypersistence Optimizer and enjoying spending your time on the things that you love!

Introduction

I previously wrote about the benefits of connection pooling and why monitoring it is of crucial importance. This post will demonstrate how FlexyPool can assist you in finding the right size for your connection pools.

Know your connection pool

The first step is to know your connection pool settings. My current application uses XA transactions, therefore we use Bitronix transaction manager, which comes with its own connection pooling solution.

Accord to the Bitronix connection pool documentation we need to use the following settings:

  • minPoolSize: the initial connection pool size
  • maxPoolSize: the maximum size the connection pool can grow to
  • maxIdleTime: the maximum time a connection can remain idle before being destroyed
  • acquisitionTimeout: the maximum time a connection request can wait before throwing a timeout. The default value of 30s is way too much for our QoS

Read More

FlexyPool, reactive connection pooling

Are you struggling with performance issues in your Spring, Jakarta EE, or Java EE application?

Imagine having a tool that could automatically detect performance issues in your JPA and Hibernate data access layer long before pushing a problematic change into production!

With the widespread adoption of AI agents generating code in a heartbeat, having such a tool that can watch your back and prevent performance issues during development, long before they affect production systems, can save your company a lot of money and make you a hero!

Hypersistence Optimizer is that tool, and it works with Spring Boot, Spring Framework, Jakarta EE, Java EE, Quarkus, Micronaut, or Play Framework.

So, rather than allowing performance issues to annoy your customers, you are better off preventing those issues using Hypersistence Optimizer and enjoying spending your time on the things that you love!

Introduction

When I started working on enterprise projects we were using J2EE and the pooling data source was provided by the application server.

Enterprise Application Server

Scaling up meant buying more powerful hardware to support the increasing request demand. The vertical scaling meant that for supporting more requests, we would have to increase the connection pool size accordingly.

Horizontal scaling

Our recent architectures shifted from scaling up to scaling out. So instead of having one big machine hosting all our enterprise services, we now have a distributed service network.

Enterprise Architecture

This has numerous advantages:

  • Each JVM is tuned according to the hosted service intrinsic behaviour. Web nodes employ the concurrent low pause collector, while batch services use the throughput collector
  • Deploying a batch service doesn’t affect the front services
  • If one service goes down it won’t affect the rest

Read More

The anatomy of Connection Pooling

Are you struggling with performance issues in your Spring, Jakarta EE, or Java EE application?

Imagine having a tool that could automatically detect performance issues in your JPA and Hibernate data access layer long before pushing a problematic change into production!

With the widespread adoption of AI agents generating code in a heartbeat, having such a tool that can watch your back and prevent performance issues during development, long before they affect production systems, can save your company a lot of money and make you a hero!

Hypersistence Optimizer is that tool, and it works with Spring Boot, Spring Framework, Jakarta EE, Java EE, Quarkus, Micronaut, or Play Framework.

So, rather than allowing performance issues to annoy your customers, you are better off preventing those issues using Hypersistence Optimizer and enjoying spending your time on the things that you love!

Introduction

All projects I’ve been working on have used database connection pooling and that’s for very good reasons. Sometimes we might forget why we are employing one design pattern or a particular technology, so it’s worth stepping back and reason on it. Every technology or technological decision has both upsides and downsides, and if you can’t see any drawback you need to wonder what you are missing.

The database connection life-cycle

Every database read or write operation requires a connection. So let’s see how database connection flow looks like:

Connection Lifecycle

The flow goes like this:

  1. The application data layer ask the DataSource for a database connection
  2. The DataSource will use the database Driver to open a database connection
  3. A database connection is created and a TCP socket is opened
  4. The application reads/writes to the database
  5. The connection is no longer required so it is closed
  6. The socket is closed

You can easily deduce that opening/closing connections are quite an expensive operation. PostgreSQL uses a separate OS process for every client connection, so a high rate of opening/closing connections is going to put a strain on your database management system.

The most obvious reasons for reusing a database connection would be:

  • reducing the application and database management system OS I/O overhead for creating/destroying a TCP connection
  • reducing JVM object garbage

Read More

Maven and Java multi-version modules

Are you struggling with performance issues in your Spring, Jakarta EE, or Java EE application?

Imagine having a tool that could automatically detect performance issues in your JPA and Hibernate data access layer long before pushing a problematic change into production!

With the widespread adoption of AI agents generating code in a heartbeat, having such a tool that can watch your back and prevent performance issues during development, long before they affect production systems, can save your company a lot of money and make you a hero!

Hypersistence Optimizer is that tool, and it works with Spring Boot, Spring Framework, Jakarta EE, Java EE, Quarkus, Micronaut, or Play Framework.

So, rather than allowing performance issues to annoy your customers, you are better off preventing those issues using Hypersistence Optimizer and enjoying spending your time on the things that you love!

Introduction

In this article, you are going to learn how to configure Maven to choose a specific Java version when the OS has multiple Java versions installed.

For instance, FlexyPool uses Java 8 for all modules, except for the flexy-pool-core-java9 module that needs to be built using Java 9.

Read More

MongoDB 2.6 is $out

Are you struggling with performance issues in your Spring, Jakarta EE, or Java EE application?

Imagine having a tool that could automatically detect performance issues in your JPA and Hibernate data access layer long before pushing a problematic change into production!

With the widespread adoption of AI agents generating code in a heartbeat, having such a tool that can watch your back and prevent performance issues during development, long before they affect production systems, can save your company a lot of money and make you a hero!

Hypersistence Optimizer is that tool, and it works with Spring Boot, Spring Framework, Jakarta EE, Java EE, Quarkus, Micronaut, or Play Framework.

So, rather than allowing performance issues to annoy your customers, you are better off preventing those issues using Hypersistence Optimizer and enjoying spending your time on the things that you love!

Introduction

MongoDB is evolving rapidly. The 2.2 version introduced the aggregation framework as an alternative to the Map-Reduce query model. Generating aggregated reports is a recurrent requirement for enterprise systems and MongoDB shines in this regard. If you’re new to it you might want to check this aggregation framework introduction or the performance tuning and the data modelling guides.

Read More

Effective learning techniques for software craftsmen

Are you struggling with performance issues in your Spring, Jakarta EE, or Java EE application?

Imagine having a tool that could automatically detect performance issues in your JPA and Hibernate data access layer long before pushing a problematic change into production!

With the widespread adoption of AI agents generating code in a heartbeat, having such a tool that can watch your back and prevent performance issues during development, long before they affect production systems, can save your company a lot of money and make you a hero!

Hypersistence Optimizer is that tool, and it works with Spring Boot, Spring Framework, Jakarta EE, Java EE, Quarkus, Micronaut, or Play Framework.

So, rather than allowing performance issues to annoy your customers, you are better off preventing those issues using Hypersistence Optimizer and enjoying spending your time on the things that you love!

Go in one ear and out the other

Programming languages, operating systems, SQL, NoSQL, web frameworks, Spring, Java EE, HTML, JavaScript, Agile methodologies, you name it. A developer must know a ridiculous amount of things to become effective. There’s no wonder many of us are struggling to keep pace with the ever-changing programming landscape.

When you’re a kid, doing stuff is the most natural way of learning, but then you go to school and you’re brainwashed into thinking that reading is the only way of studying.

Become an active learner

Ever since I started writing this blog I began to question my old ways of learning. I used to be a passive learner, reading books, articles or watching videos. But I realized this is not working the way it should, so I started looking for alternatives.

Edgar Dale‘s evaluated the most common learning techniques and came up with the famous Cone of experience. Basically, if you want to be a better developer you need to become an active learner.

Writing a blog

Until you start writing, you don’t really appreciate the actual effort put into coming up with a decent article. Writing down your findings not only helps the community, it helps you too. The writing process is going to teach you more about a given subject. You want to publish quality articles and the upcoming critique is going to be a good motivator.

Read More

The Builder pattern and the Spring framework

Are you struggling with performance issues in your Spring, Jakarta EE, or Java EE application?

Imagine having a tool that could automatically detect performance issues in your JPA and Hibernate data access layer long before pushing a problematic change into production!

With the widespread adoption of AI agents generating code in a heartbeat, having such a tool that can watch your back and prevent performance issues during development, long before they affect production systems, can save your company a lot of money and make you a hero!

Hypersistence Optimizer is that tool, and it works with Spring Boot, Spring Framework, Jakarta EE, Java EE, Quarkus, Micronaut, or Play Framework.

So, rather than allowing performance issues to annoy your customers, you are better off preventing those issues using Hypersistence Optimizer and enjoying spending your time on the things that you love!

Introduction

In this article, we are going to see how we can use the Builder pattern when creating beans with the Spring framework.

I like to make use of the builder pattern whenever an object has both mandatory and optional properties. But building objects is usually the Spring framework responsibility, so let’s see how you can employ it using both Java and XML-based Spring configurations.

Read More