<p>I am reviewing a big java application to see if there are any performance bottlenecks. The real problem is that I cannot pinpoint the performance issues to any single module. The whole application is slow as such.</p>

<p>Is there some tool/technique I can use to help me out in this?</p>

[{'answer_id': 37934, 'author': 'Bartosz Bierkowski', 'author_id': 3666, 'author_profile': 'https://Stackoverflow.com/users/3666', 'pm_score': 4, 'selected': True, 'text': '<p>Try using a profiler on your running code. It should help you identify the bottlenecks. Try <a href="http://www.ej-technologies.com/products/jprofiler/overview.html" rel="noreferrer">jprofiler</a> or <a href="http://www.netbeans.org/features/java/profiler.html" rel="noreferrer">Netbeans profiler</a></p>\n'}, {'answer_id': 37942, 'author': 'HadleyHope', 'author_id': 3416, 'author_profile': 'https://Stackoverflow.com/users/3416', 'pm_score': 2, 'selected': False, 'text': '<p>If you are running on Java 6 you can use the <a href="http://java.sun.com/developer/technicalArticles/J2SE/monitoring/" rel="nofollow noreferrer">supplied monitoring tools</a></p>\n'}, {'answer_id': 39050, 'author': 'Tnilsson', 'author_id': 4165, 'author_profile': 'https://Stackoverflow.com/users/4165', 'pm_score': 0, 'selected': False, 'text': '<p>For testing/development purposes, you can download Oracle JRockit Mission Control for free from <a href="http://www.oracle.com/technology/software/products/jrockit/index.html" rel="nofollow noreferrer">this</a> site. (Requires Login, but accounts can be set up with any email adress)</p>\n\n<p>Docs <a href="http://www.oracle.com/technology/products/jrockit/missioncontrol/index.html" rel="nofollow noreferrer">Here</a>. It will allow you to find hotspots, memory leaks and much more.</p>\n'}, {'answer_id': 39056, 'author': 'wvdschel', 'author_id': 2018, 'author_profile': 'https://Stackoverflow.com/users/2018', 'pm_score': 3, 'selected': False, 'text': "<p>I'm often happy enough using <code>Java -Xprof</code>. This gives you a sorted list of the functions your code spends most of its time in.</p>\n"}, {'answer_id': 15366010, 'author': 'peceps', 'author_id': 590531, 'author_profile': 'https://Stackoverflow.com/users/590531', 'pm_score': 0, 'selected': False, 'text': '<p><a href="http://www.yourkit.com/" rel="nofollow">YourKit</a> is a excelent java profiler (not free). </p>\n'}, {'answer_id': 15366173, 'author': 'Riking', 'author_id': 1210278, 'author_profile': 'https://Stackoverflow.com/users/1210278', 'pm_score': 0, 'selected': False, 'text': '<p>As we see from  <a href="https://stackoverflow.com/questions/375913/what-can-i-use-to-profile-c-code-in-linux">How can I profile C++ code running in Linux?</a>, the most statistically significant approach is to use a stack profiler.</p>\n\n<p>Well, Java runs in the JVM, so getting a stack useful for C code won\'t be useful for us (it\'ll get the JVM stuff, not your code). Fortunately, Java has <code>jstack</code>! <a href="http://docs.oracle.com/javase/1.5.0/docs/tooldocs/share/jstack.html" rel="nofollow noreferrer">http://docs.oracle.com/javase/1.5.0/docs/tooldocs/share/jstack.html</a></p>\n\n<p>It\'ll give you a bunch of threads, like the GarbageCollector. Don\'t worry about those, just look at where your threads are.</p>\n'}]
['https://Stackoverflow.com/questions/37929', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/184/']