The application that we are going to discuss in this post was running on Elastic Beanstalk (EBS) service in Amazon Web Services (AWS). Intermittently this application was throwing HTTP 502 Bad Gateway error. In this post, let’s discuss how we... Continue Reading →
c1, c2 compiler threads are created by Java virtual machine to optimize your application's performance. Occasionally these threads will tend to consume high CPU. In this post, let’s learn little more about c1, c2 compiler threads and how to address... Continue Reading →
java.lang.ClassLoader#loadClass() API is used by 3rd party libraries, JDBC Drivers, frameworks, application servers to load a java class into the memory. Application developers don’t use this API frequently. However when they use the APIs such as ‘java.lang.Class.forName()’ or ‘org.springframework.util.ClassUtils.forName()’, they... Continue Reading →
There are a good number of articles that articulate functional differences between HashMap, HashTable and ConcurrentHashMap. This post compares the performance behavior of these data structures through practical examples. If you don't have patience to read the entire post, here... Continue Reading →
Java developers tend to use 'java.util.UUID#randomUUID()' API, to generate a UUID (Universally Unique Identifier) number (i.e., 'b8bbcbed-ca07-490c-8711-5118ee0af2f9'). Under certain circumstances, using this API can affect your application’s availability. Let’s discuss this API in this post with a real-world example. How... Continue Reading →
'java.lang.System.getProperty()' is a common API used by Java developers to read the System properties that are configured during application startup time. i.e. when you pass "-DappName=buggyApp" as your application's startup JVM argument, the value of the 'appName' system property can... Continue Reading →
Java applications tend to contain hundreds (sometimes thousands) of threads. The majority of these threads are in WAITING, TIMED_WAITING (i.e., dormant) state, while only a small portion of the threads are actively executing lines of code. So, we were curious... Continue Reading →
Java Virtual Machine (JVM) generates 3 critical artifacts that are useful for optimizing the performance and troubleshooting production problems. Those artifacts are: Garbage collection (GC) logThread DumpHeap Dump In this article let us try to understand these 3 critical artifacts,... Continue Reading →
Threads that are throwing Exception or Errors should be investigated. Because those threads stack trace indicates the origin of the problem. Below is the stack trace of the thread that is throwing java.lang.OutOfMemoryError: Thread 0x3ff781e764e0 at java.lang.OutOfMemoryError.<init>()V (OutOfMemoryError.java:48) at java.lang.ClassLoader.defineClass1(Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;... Continue Reading →