How To Avoid Out Of Memory Error
in Java Everyone in java development faces java.lang.OutOfMemoryError now and then, OutOfMemoryError in Java is one problem which is more due to system's limitation (memory) rather than due to programming mistakes in most cases though in certain cases you could have a memory leak which causing OutOfMemoryError. I have found that even though java.lang.OutOfMemoryError is quite common basic knowledge of its cause and solution is largely unknown among junior developers. Beginners books like Head First Java doesn't teach you much about how to deal with this kind of error. You need real experience dealing with production systems, handling a large number of user sessions to troubleshoot and fix performance issues like running out of memory. If you want to be good at troubleshooting and performance analysis, you need to learn some books on Java performance and profiling e.g. Java Performance The Definitive Guide By Scott Oaks or the Java Performance by Binu John. They are an excellent resource for senior Java developers and also teaches you tools and process to deal with an error like java.lang.OutOfMemoryError. In this article, we will explore what is java.lang.OutOfMemoryError; Why OutOfMemoryError comes in Java application, different type of OutOfMemoryError and How to fix OutOfMemoryError in Java. This article is purely meant to provide basic knowledge of java.lang.OutMemoryError and won't discuss profiling in detail. For profiling read the books I have mentioned before. What is java.lang.OutOfMemoryError in Java OutOfMemoryError in Java is a subclass of java.lang.VirtualMachineError and JVM throws java.lang.OutOfMemoryError when it ran out of memory in the heap. OutOfMemoryError in Java can come anytime in heap mostly while you try to create an object and there is not enough space on the heap to allocate that objec
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Out Of Memory Errors, or OOMEs, are one of the most common problems faced by Apache Tomcat users. Generally, these errors occur during development, but can even occur on production https://www.mulesoft.com/tcat/tomcat-oome-out-of-memory-error servers that are experiencing an unusually high spike of traffic. Tomcat 7 includes fixes and workarounds to prevent some of the causes of OOMEs, but nothing substitutes a good understanding of why these errors occur. This guide will help you understand why these errors are so prevalent and seemingly hard to fix, and show you how organizations using Apache Tomcat in enterprise production how to environments use Tcat to fix and avoid these errors. What Causes An OOME? The literal cause of an Out Of Memory Error is simple: a given Tomcat instance uses up all of the heap memory allocated to it, causing an application or server crash. Thus, the errors themselves are not particularly puzzling. The reason why OOMEs have become such a persistent how to avoid topic of discussion in the Apache Tomcat community is that they are difficult to trace to their root cause. A stack trace will not show the cause, as the problem usually lies not with Tomcat, but the web application. Meanwhile, the 'incorrect' web app code causing Tomcat to run out of memory is usually technically correct. That is to say, in any context other than a container managed environment, the code would be considered standard. It is easy to see why a developer might have trouble determining which 'correct' section of their code was incorrect. Here are some of the most common root causes of an OOME: a simple case of the heap size being too small running out of file descriptors more open threads than the host OS allows code with high amounts of recursion code that loads a very large file into memory code that retaining references to objects or classloaders a large number of web apps and a small PermGen Fixing Out Of Memory Errors If you are encountering Out Of Memory Errors, the first step is to determine exactl