jstack2devtools
Converts java stacktraces to Chromium DevTools format .json
Profile your app simply without RMI/Java agent
Method similar to VisualVM sampler and JProfiler, but better - contains Timeline, which allows you to spot when the lag spike happened and what caused it (if it wasn't GC).
Building
go build github.com/Szperak/jstack2devtools
Running
Paste your stacks.txt to the workdir.
Run ./jstack2devtools and import events.json in your DevTools.
Generating smoother samples than jstack
String threadName = "Client thread";
Thread jt = getThreadByName(threadName);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
long lastTime = System.nanoTime();
for(int i = 0; i<20000; i++) {
baos.write('"');
baos.write(jt.getName().getBytes(StandardCharsets.UTF_8));
baos.write('"');
baos.write('\n');
StackTraceElement[] stack = jt.getStackTrace();
for(StackTraceElement el : stack) {
baos.write("\tat ".getBytes(StandardCharsets.UTF_8));
String stackElement = "";
if(el != null){
stackElement = el.getClassName()+"."+el.getMethodName()+"("+el.getFileName()+":"+el.getLineNumber()+")";
}
baos.write(stackElement.getBytes(StandardCharsets.UTF_8));
baos.write('\n');
}
long now = System.nanoTime();
baos.write(Long.toString(now-lastTime).getBytes(StandardCharsets.UTF_8));
baos.write('n');
baos.write('s');
baos.write('\n');
lastTime = now;
Thread.sleep(0, 1000*500);
}
String fileName = "stacks.txt";
FileOutputStream fos = new FileOutputStream(fileName);
fos.write(baos.toByteArray());
fos.close();