What is memory leak in Java?
Such types of useless objects are called as Memory leaks. If allocated memory goes beyond limit, program will be terminated by rising OutOfMemoryError. Hence if an object is no longer required, it is highly recommended to make that object eligible for garbage collector.
What is wrong with substring () in Java?
When we call substring (), a new String object is created in memory. But still it refers the char [] array value from original String. This prevents bigString from Garbage collection process and we are unnecessarily storing 100000 bytes in memory (just for 2 characters). The bug details can be found here. This issue should be handled by developers.
How to suppress memory leaks in Oracle Solaris 9?
The previous example used two suppress commands to suppress the leaks reported in the virtual machine: libjvm.so and the Java support library, libjava.so. First introduced in the Oracle Solaris 9 operating system update 3, the libumem.so library, and the modular debugger mdb can be used to debug memory leaks.
What happens if memory allocation goes beyond limit in Java?
If allocated memory goes beyond limit, program will be terminated by rising OutOfMemoryError. Hence if an object is no longer required, it is highly recommended to make that object eligible for garbage collector. Otherwise We should use some tools that do memory management to identifies useless objects or memory leaks like:
The usage of memory increases during the life span of an application. There are the following causes of memory leaks in Java: Using Unwanted Object Reference: These are the object references that are no longer needed. The garbage collector is failed to reclaim the memory because another object still refers to that unwanted object.
How to solve the memory leak problem?
Using Heap Dump: It is a technique that is the solution to the memory leak problem. It is a snapshot of all objects that reside in the memory at a certain time.
How to fix memory leak problem in JVM?
There are the following solutions to the memory leak problem: Using JVM Tools: There are many tools available that optimizes the code and show the memory status. Using Heap Dump: It is a technique that is the solution to the memory leak problem.
How to detect memory leak using VisualVM?
Analysing memory leak using visualvm is not that easy. It has a tool/plugin called ‘sampler’. This can be used to sample memory or cpu. You can take snapshot at regular interval and look for possible leaks. More effective way will be to get a heap dump (say when the application has slowed down or when OOM happens).
What is OutOfMemoryError in Java?
This (java.lang.OutOfMemoryError) error is shown when there are memory leaks in Java. And, because of the Java memory leaks, sometimes your program is stuck. Java Memory Leaks is a genuine problem.