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Java Profilers - Which One Are You Using?

splitPersonality asks: "Our Java programmers are researching various profilers to use in-house. We would appreciate some feedback from other shops that are using Java profilers. Along with the specific product, would you please include reasons behind your choice? If you now have misgivings about the one you or your shop chose, please let me know about those, as well."

5 of 79 comments (clear)

  1. YourKit: awesome profiler by jnana · · Score: 5, Informative
    I give my most enthusiastic recommendation to YourKit. It takes about a minute to install, has optional integration (1-click) with Eclipse, IDEA, Netbeans. I use Eclipse, and the integration there adds a new 'Profile as' options that works just like the 'run as' and 'debug as' launch options.

    YourKit is extremely easy to use thanks to a very intuitive interface.. All the java developers I've shown it to have been as impressed as I've been. It is cheaper than most profilers -- I got a deal on it for $125 a few months ago, which I is about 25% of the normal price, but it's still cheap at $499. It's not open-source, but they have a forum where they answer they questions extremely quickly. I've had 1 or 2 bugs since I've been using it (about 10 months), since I like to use the early release version for newer features, and both have been fixed within days, with a new build released within a week or so. Memory leaks are a snap to find using it's "compare snapshot", which lets you compare 2 snapshots and shows you what the difference is -- memory leak is generally the difference if you capture your snapshots intelligently.

    Anyway, I can't speak highly enough of the product. For the record, I have no affiliation with them at all. I'm just a very happy customer.

    My only minor gripe is that under some circumstances, the fastest CPU profiling option (unnoticeable impact on the running app) can give inaccurate results, in which case I have to use one of the two slower CPU profiling options, which are much, much slower--but that's certainly not particular to YourKit.

  2. Re:Which one? Isn't it obvious... by Anonymous Coward · · Score: 4, Informative

    I use several tools depending on the application.

    For step-through-your-code debugging nothing beats Jprobe, although perhaps a fellow slashdotter
    can suggest a public domain equivalent

    If you want to profile your code in a "production" situation, i.e. you need minimal overhead
    while instrumenting methods to understand where in your stack trace time is being spent
    you have two options. Mercury Interactive sells a product that instruments all methods,
    aggregates method usage and gives you a "top talker" summary. Wyle Introscope on the other
    hand instruments only the methods you want, but can drill down into things like JDBC and capture
    executed SQL. Their product Leakhunter can help you find memory leaks, but creates too much drag for prod usage.

    Finally if want something that combines elements of Mercury's inclusive approach of instrumenting
    everything and top talker summaries and with Wyles approach of watching for heap usage, GCs and so
    on you want a copy of YourKit. I own all the products mentioned but have to say YourKit is my current favorite.

  3. JRat by Anonymous Coward · · Score: 5, Informative

    JRat is open-source, and works anywhere using bytecode injection. It's the only serious solution for profiling applications running in production as it

    A) doesn't require much overhead
    B) doesn't require code changes
    C) doesn't require some sort of front-end to monitor or use
    D) doesn't have a rediculous cost per server
    E) runs in your typical environment, not some magical profiling IDE option

    We use this every day (via an ant task) to profile a Wall Street trading system that handles billions of dollars of transactions every week. Would you trust that to anything else?

    Signing anon because my employment contract specifically prevents me from revealing this sort of thing :) Enjoy.

  4. For us... by Leftmoon · · Score: 4, Informative

    We use DevPartner which seems to work pretty well for me. It's fairly neat the way it works. Although it does seem to identify some things as memory leaks that probably aren't actually leaks (ResultSets, IBM MQ Series objects, etc), if you limit the check to your own packages, a lot of your in-house errors will stand out right way and it will ignore the (assumed) false spots. Give it a try.

  5. Re:If you care about performance... by espressojim · · Score: 3, Informative
    Often times it doesn't matter how much you profile your Java application. The bottleneck will often be hidden away, deep in some class library that either you can't modify (due to licensing restrictions or unavailable source code), or that you don't want to modify. Other times, the bottleneck will be in the inherently slow execution model of Java. Profile all you want, and change your algorithms all you want. Many times the only solution is to move away from Java in order to get the performance or scalability boost you may need.


    Last week I was profiling my code that connected to a database and retrieved data over and over. Originally, I'd bumped up the memory size on my VM to let the code run, because it was analysis code and didn't need to be super efficient until we moved it over to where the public could access it.

    The memory leak turned out to be in Oracle's jdbc driver. The TTCItem class was not being garbage collected, and a HUGE amount of memory (think everything sent over the wire from the database) was collecting. So, as you said, I had a bottle neck hidden away in a class library, and there was nothing I could do about it.

    Then I downloaded the latest oracle ojcbc14.jar, where I'd read on some forums that they'd patched the memory leak, and the problem went away. The problem was solved, the VM was running at 6M memory, and I was happy.

    If I hadn't had a profiling tool, I NEVER would have found that leak and fixed it. Who knew some versions of the oracle driver have a memory leak in their prepared statement handing? The solution isn't to walk away from Java, but to learn how to use the appropriate tools and programming techniques.