Top 11 Java Application Performance Problems

Java Performance Problems

One of the most widely used technologies for application development is Java. Java supports tens of thousands of corporate applications, and millions of individuals use it regularly. All Java application developers are interested in its performance because making an application quick is just as essential as creating it functional. Experts divide fundamental performance concerns into three categories.

Top 3 Categories of Java Application Performance Problems

Database Problems

Because the database is the foundation of an application’s functionality, it is also the source of most performance issues.

Problem #1: Persistence configuration

Problems arise as the application’s load grows, resulting in a significantly larger database load.

So, to address this, look at the business transaction counts, database counters, and the link between a business transaction and database calls.

To avoid such problems, you must thoroughly understand the persistence technology in use and appropriately configure all configuration settings so that its functionality is aligned with your business domain’s requirements.

Also Read: Find $1M costing defect before end-user reports


Because in-memory data is faster to access than persistent data, caching has improved application speed.

Problem #2: No Caching

When no caching is utilized, problems arise because it must be fetched from the database each time a resource is needed. When caching is employed, issues arise as a result of improper configuration.

It is important to note the fixed size of a cache and the distributed cache setup. Unlike pools, which provide stateless objects, cached objects are stateful. As a result, a cache must be appropriately set to avoid memory exhaustion.

Also, to avoid problems when the removed object is requested again. This ‘miss’ ratio, as well as the memory, must be adjusted in cache settings.

Problem #3: Distributed caching

When many caches are set to many servers, synchronization is required. As a result, a cache update is propagated to all servers’ caches. When caching is implemented effectively, an increase in application load does not increase database load. However, the database load rises if the cache settings are incorrect, resulting in CPU overhead and an even disc I/O rate.

To troubleshoot this issue, you should first assess database performance to determine whether or not the cache is required. Then, using the hit ratio and miss ratio measurements, compute the cache size. However, you may prevent caching issues by adequately designing your application before using it. Make sure to utilize serialization and scalable methods in your application.

Problem #4: Pool connections

The size of the pool is crucial. When there aren’t enough connections, business transactions are delayed, and the database is underutilized. Too many connections, on the other hand, result in a longer response time and database overload.

To resolve this, determine if your application is awaiting the establishment of a new connection or the execution of a database query.

You may always avoid that by optimizing the database and testing the program with various pool sizes to see which one works best in your situation.

Memory Problems

Garbage Collector and memory leaks are to blame for memory issues.

Problem #5: Garbage Collector

Garbage collection may force all threads to pause so that memory may be reclaimed. There is a concern when this operation takes too long or occurs too frequently. CPU spikes and long reaction times are the most common symptoms.

You can fix this by configuring your -verbosegc parameters, using a performance monitoring tool to detect large GC events, and monitoring heap use and any CPU spikes with a tool. It’s tough to prevent this issue. You may mitigate it by adjusting heap size and restarting your JVM.

Problem #6: Memory leaks

Because memory leaks in Java are more of a reference management issue than in C or C++, they can arise in various ways. In Java, you can keep a reference to an object even if you’re not going to use it again. This may cause an OutOfMemory error, requiring a JVM restart. A memory leak occurs when memory use rises to the point that the heap runs out of space.

To solve it, you could configure the JVM parameters properly.

To avoid this, you can pay attention while coding to memory leak–sensitive Java collections or session management. Have an expert take a look at your application code, and use tools to avoid memory leaks and analyze heap.

Concurrency Problems

When several calculations are run at the same time, this is known as concurrency.

Problem #7: Thread deadlocks

Thread deadlocks happen when two or more threads try to access the same resource while waiting for the other to release it, and vice versa. When a deadlock occurs, the JVM exhausts all threads, slowing down the program. It’s pretty tough to recreate a deadlock.

Capturing a thread dump while two threads are blocked and examining stack traces of the threads is one approach to address a deadlock situation.

To avoid this issue, make your program and its resources as immutable as feasible, utilize synchronization, and check for potential thread interactions.

Problem #8: Thread gridlocks

When too much synchronization is utilized, thread gridlocks can develop, resulting in too much time waiting for a single resource. You’ll notice this if your reaction times are long and your CPU usage is low because several threads are attempting to access the same code portion and are waiting for the one who has it to complete.

To remedy this, you must first determine where and why your threads are waiting. Then, based on your company’s needs, you should remove the synchronization requirements.

Problem #9: Thread pool configuration locks

A thread pool regulates the simultaneously handled requests when an application utilizes an application server or a web container. If this thread pool is too tiny, requests will be delayed significantly, but processing resources will be overburdened if it is too huge. So, at a small pool size, the CPU is underutilized, but the thread pool is fully utilized, and at a big pool size, the CPU is underutilized, but the thread pool is fully utilized.

You may simply troubleshoot this problem by looking at your thread pool and CPU consumption and deciding whether to expand or contract the pool size. To avoid that, you’ll need to fine-tune the thread pool, which isn’t straightforward.

Problem #10: Java Code-Level Issues

Most code-level problems are caused by code structure errors, such as long waits, incorrect iterations, inefficient code algorithms, and improper selection of data structures. Most often, programming problems manifest themselves as loops that occupy CPU cycles in the JVM.
Therefore, performance issues can occur with third-party frameworks used in application development.

To solve this problem, combine code optimization practices to ensure that your application code meets the expected standards. Use transaction analysis tools to isolate problems at the code level automatically.

To avoid this problem, all code-level issues should be captured by the QA team and corrected by the development team before being released to production. But this is not always the case.

Problem #11: Java Application Server Bottlenecks

The application server bottleneck will directly affect business transactions, application performance, and the end-user experience. Issues in servlet execution, bean caching, queues, and JDBC connections will affect performance.

Transaction rollback is another issue that needs to be addressed. But no-app rollback is a severe problem that needs to be resolved immediately. There are three types of non-application rollbacks:

The system rollback is due to a problem with the Java application server.
The timeout rollback is due to a process timeout in the Java container.
The Resource rollback occurs when a resource management problem occurs in Java Container.

To solve this, use Application Performance Monitoring Tools to monitor end-to-end Java application servers’ health, availability, and performance. Track key application server metrics to understand anomalies and anti-patterns.

Methods to Improve Performance of Java Applications

  • Use Regular Expressions Carefully
  • Avoid recursion when possible
  • Run Performance test suite
  • Use StringBuilder for concatenation of strings
  • Use the Stack and Avoid the Heap
  • Use Concurrency control strategy
  • Caching
  • Implement EnumSet
  • Smart Thread Handling
  • Check JDBC Performance/ Use JDBC batching.

It is critical for developers to code effectively and for testers to identify and report bugs. IT departments should also take proactive efforts to ensure that essential performance management mechanisms are in place. Monitoring should not be an afterthought for businesses creating, hosting, implementing, and using Java-based applications. With Seagence, Performance problems in Java are automatically tracked and triaged, making troubleshooting simpler. Try it out today!

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