Consider using HPROF and opening the data file with a tool like HPjmeter – or just reading the resulting text file in your favorite editor. Command used: javac -J-agentlib:hprof=heap=sites Hello.java SITES BEGIN (ordered by live bytes) Fri Oct 22 11:52:24 2004 percent live alloc’ed stack class rank self accum bytes objs bytes objs trace name … Read more
I found that this was the issue of usage of wrong JDK version. In my case my application was running on 64bit JDK and I started VisualVM from 32bit JDK. After starting VisualVM from the same JDK on which my application is running, everything was fine. Hope it will help you.
I had the same issue after java 1.7.0_45 update. I had to delete the following folder: C:\users\’username’\AppData\Local\Temp\hsperfdata_’username’ After doing so, everything works like a charm.
See this bug report – VISUALVM-637 Solution: start JVisualVM using below command : jvisualvm.exe -J-Dorg.netbeans.profiler.separateConsole=true I’ve checked this (and it works !) at Windows 10 X64 with java version “1.8.0_102”
In general: A profiler is running all the time, so it gives you the complete call stack; at any given point in time. A sampler only takes “snapshots” at distinct point in times. Thing is: when you “profile” everything, then that slows down your JVM significantly; and it creates enormous amounts of data within a … Read more
Please check your network configuration. I expericened the same issue. It can work when I set network configuration with ‘No Proxy’. Main menu: tools/options/network/no proxy.
Strings are problematic Basically in Java, String references ( things that use char[] behind the scenes ) will dominate most business applications memory wise. How they are created determines how much memory they consume in the JVM. Just because they are so fundamental to most business applications as a data type, and they are one … Read more
I found out that (at least under Windows) one can easily write small batch files to run VisualVM in combination with specific JVMs, which is important for me, since I have installed the 32bit JDK alongside with the 64bit JDK (I need both, so this is sensible for me). I have created two batch files … Read more
You either need to run jstatd on the remote side, or specify a JMX connection using host:port. Jstatd: jstatd -J-Djava.security.policy=permissions.txt [-p port] After that: add a remote connection to the target machine, and on the properties of that remote connection configure the jstatd connection. (permissions.txt contains for example this: grant { permission java.security.AllPermission; }; Edit: … Read more
Looking at the trace data in a “snapshot” view allows you to see the total as well as the self time. Press the “snapshot” button that appears about the table of results. This will create a new tab that contains a “Call Tree” view which breaks down the self vs. total time. The “combined” view … Read more