问题
Occasionally I have to do some profiling work on Java code, and I would like to know why I should have my boss investigate in a commercial profiler as opposed to just use the one in Netbeans or JConsole?
What would the killer features be that would warrant the investment?
回答1:
I have experience using both NetBeans profiler and JProbe. For performance profiling I have found Netbeans quite useful but where JProbe is superior is for memory profiling.
JProbe has superior tools for comparing heap snapshots and finding the root cause of a memory leak. For example, in JProbe you can view heap shapshots visually as a graph, select nodes to investigate and then delete references to see if the instance could then be garbage collected.
回答2:
In my experience with JProfiler, it's just an all-round slicker experience than the NetBeans profiler. It's easier to get started, easier to interpret the information and, although I haven't measured it, it seems that JProfiler has less of a negative impact on the performance of the application being profiled.
Also, JProfiler integrates nicely with IntelliJ IDEA. I have to use NetBeans to use the NetBeans profiler, which is an inconvenience because I have to manually configure a free-form project to match the layout of my project.
The NetBeans profiler is usable. Unlike IntelliJ, I wouldn't buy a JProfiler licence for my personal projects because, unlike an IDE, it's not a tool you use all day every day. However, for paid work there's no reason not to buy a better tool. It's not expensive compared to the cost of a developer's time.
回答3:
If you are using Netbeans already then starting up the profiler is easy (unless you are using a Maven based project... sigh).
I have used paid profilers as well as the Netbeans one. Netbeans does the job well enough (it was a bit rough when it first came out... but much better now).
The code I profile isn't HUGE so I cannot say if the time spent in profiling is a major factor.
The answer is highly subjective and totally depends on your needs. Things to look at:
1) ease of use in your environment (in the case of NetBeans it is likely that the built in profiler is easiest.
2) time spent starting the prfiler to it actually getting you usable results
3) is it a sampling or tracing profiler? (An overview is here: http://docs.hp.com/en/5992-0757/ch05s01.html
4) can you view the results live or do you have to wait for the profiling to finish?
Here is a link to a slashdot discussion on Java profilers: http://ask.slashdot.org/article.pl?sid=06/06/30/0053237
回答4:
I've not used Netbeans profiler, but tried JProfiler, Yourkit and JProbe. I found Yourkit slightly better (mainly bought by the usability aspect). Some of the useful features in it are: (you can check if it is available in Netbeans)
- J2EE Profiling (Eg. It shows how much time an SQL query took).
- Snapshot comparison and annotation
- Deadlock detector
- Exception telemetry
You can check for more details at their site.
回答5:
I would say that, ready to use and more performance statistics. I was assigned a profiling job last year when I was interning at a multinational. I used the InfraRED profiler which uses Java aspect oriented API (works with both Aspectwerkz and AspectJ). But I had to extend the profiler to get what my manager wanted. Also, the performance statistics given by the profiler was limited.
But before selecting the profiler I researched a few other opensource profilers. Some of them were trivial and didnt suit what we wanted.
I would also add that, some of them just doesnt work. For example, if we want to collect performance statistics of a web application, all the profilers doesnt support those statistics required for us.
回答6:
With a completely independent profiler, it's much easier to integrate it with other applications in your toolchain. For example, say you want to run the profiler as part of your build process (say, once a night). Something like JProfiler easily integrates with ANT, whereas profilers built into IDEs may or may not. If you have a separate build machine, installing a local copy of a profiler makes sense, but installing a whole IDE just to get access to one component does not.
回答7:
If you are using Tomcat you might consider lambdaprobe
http://www.lambdaprobe.org/
(It is for free)
回答8:
From my experience, YourKit profiler is most usable one. Small usability things really make the difference, but also it is most comprehensive one, containing:
- most comprehensive and usable memory snapshots (working also with 1GB+ heaps), with detail object view and primitive data, for every single object. (for example in hashmap you can see if objects are evenly distributed or most are stored in same bucket!) This detail of memory snapshots and its ease of use is my main reason for yourkit.
- very little overhead (far less then many other profilers I used)
- comparing snapshots
- J2EE profiling
- deadlock detector, lock status (I think it still misses java.concurrent.locks, bud for synchronized it is great)
Among other things, it's also constantly improving, so who knows what is future holding :)
回答9:
Compare the features and see if you really need the features provided by commercial software over the free one. If yes then its worth investing.
来源：https://stackoverflow.com/questions/490858/what-advantages-have-a-commercial-java-profiler-over-the-free-ones-e-g-the-one