Our company deployed a lastest openfire server (3.7.1 alpha) for production test.
We found that after running for several hours, the openfire server always has a
100% CPU usage.
By using the jvirtualVM to monitor the CPU usage sample graph, we found this
is caused by the read() method (see the code below) of the FlashCrossDomainHandler
class. it can run into a infinite loop under some circumstances.
protected String read(BufferedReader in) {
StringBuffer buffer = new StringBuffer();
int codePoint;
boolean zeroByteRead = false;
try {
do {
codePoint = in.read();
if (codePoint == 0 || codePoint == ‘\n’) {
zeroByteRead = true;
}
else if (Character.isValidCodePoint(codePoint)) {
buffer.appendCodePoint(codePoint);
}
}
while (!zeroByteRead && buffer.length() < 200);
}
catch (Exception e) {
Log.debug("Exception (read): " + e.getMessage());
}
return buffer.toString();
}
Then we commented the read() method, the validation of the incoming stream and
returned the cross domain policy text straightway in while loop of the startServer()
method , as the result the CPU usage became normal.