Book Image

Java EE 8 High Performance

By : Romain Manni-Bucau
Book Image

Java EE 8 High Performance

By: Romain Manni-Bucau

Overview of this book

The ease with which we write applications has been increasing, but with this comes the need to address their performance. A balancing act between easily implementing complex applications and keeping their performance optimal is a present-day need. In this book, we explore how to achieve this crucial balance while developing and deploying applications with Java EE 8. The book starts by analyzing various Java EE specifications to identify those potentially affecting performance adversely. Then, we move on to monitoring techniques that enable us to identify performance bottlenecks and optimize performance metrics. Next, we look at techniques that help us achieve high performance: memory optimization, concurrency, multi-threading, scaling, and caching. We also look at fault tolerance solutions and the importance of logging. Lastly, you will learn to benchmark your application and also implement solutions for continuous performance evaluation. By the end of the book, you will have gained insights into various techniques and solutions that will help create high-performance applications in the Java EE 8 environment.
Table of Contents (12 chapters)

Testing the application

Before starting to work on our application from the performance window, let's get a bit familiar with it. We will not browse and test all the endpoints but just check how to get a price using the JAX-RS layer and WebSocket layer. In other words, we will define two customer use cases of our application.

The goal here is to ensure that we know how to use the application to be able to write test scenarios later. To do so, we will execute some requests manually on both fronts (HTTP and WebSocket).

Get a quote price the JAX-RS way

The endpoint we saw previously has been deployed on /<application_context>/api/quote/{quoteId} with the context of the web application, application_context. If you used the previous setup, it is, most likely, the artifact ID of the Maven project. Let's consider from now on that it is quote-manager.

Here is what it returns for one of the quotes:

$ curl -v http://localhost:9090/quote-manager/api/quote/8
* Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 9090 (#0)
> GET /quote-manager/api/quote/8 HTTP/1.1
> Host: localhost:9090
> User-Agent: curl/7.52.1
> Accept: */*
>
< HTTP/1.1 200 OK
< Server: Undefined Product Name - define product and version info in config/branding 0.0.0
< X-Powered-By: Servlet/3.1 JSP/2.3 (Undefined Product Name - define product and version info in config/branding 0.0.0 Java/Oracle Corporation/1.8)
< Content-Type: application/json
< Content-Length: 54
<
* Curl_http_done: called premature == 0
* Connection #0 to host localhost left intact
{"id":8,"name":"JOBS","customer_count":0,"value":59.4}

This kind of application often needs a kind of index endpoint to be able to browse quotes (in a nice user interface or a command-line interface, for instance). In our case, it is our find all endpoint, which supports pagination through the query parameters. Here is how to use it and the kind of data it returns:

$ curl -v http://localhost:9090/quote-manager/api/quote?from=0&to=5
* Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 9090 (#0)
> GET /quote-manager/api/quote?from=0 HTTP/1.1
> Host: localhost:9090
> User-Agent: curl/7.52.1
> Accept: */*
>
< HTTP/1.1 200 OK
< Server: Undefined Product Name - define product and version info in config/branding 0.0.0
< X-Powered-By: Servlet/3.1 JSP/2.3 (Undefined Product Name - define product and version info in config/branding 0.0.0 Java/Oracle Corporation/1.8)
< Content-Type: application/json
< Content-Length: 575
<
{"total":10,"items":[{"id":1,"name":"FLWS","customer_count":0,"value":9.0},{"id":2,"name":"VNET","customer_count":0,"value":5.19},{"id":3,"name":"XXII","customer_count":0,"value":2.2},{"id":4,"name":"TWOU","customer_count":0,"value":50.1},{"id":5,"name":"DDD","customer_count":0,"value":12.56},{"id":6,"name":"MMM","customer_count":0,"value":204.32},{"id":7,"name":"WBAI","customer_count":0,"value":10.34},{"id":8,"name":"JOBS","customer_count":0,"value":59.4},{"id":9,"name":"WUBA","customer_count":0,"value":62.63},{"id":10,"name":"CAFD","customer_count":0,"value":14.42}]}

Get the price, the WebSocket way

The WebSocket endpoint is deployed on /<application_context>/quote, and some exchanges can look like the following:

connect> ws://localhost:9090/quote-manager/quote
send> {"name":"VNET"}
received< {"found":true,"value":5.19}
send> {"name":"DDD"}
received< {"found":true,"value":12.56}
disconnect>
Connection closed: Close status 1000 (Normal Closure)

What is interesting to see in this communication dump is the fact that the connection lasts for more than one request, and it is based on the symbol more than the identifier (compared to the previous JAX-RS samples).