Tag Archives: linux

Java, SecureRandom and /dev/random gotchas

After running flawlessly for several months a Java server applications we’re using in SpamDrain started to lock up very frequently. A thread dump taken during such a lock up revealed that all the handler threads were stuck inside a call to java.security.SecureRandom.nextInt(). By reading the source code of the SHA1PRNG SecureRandom implementation I figured out that it uses /dev/random under Linux for its source of random numbers. This was the cause of the lock ups.

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Getting the mic working on a Dell Dimension 5000 running Ubuntu 8.04

I’ve been trying hard to get the microphone working on my wife Jenny’s old Dell Dimension 5000 running Ubuntu 8.04. Google wasn’t much help I’m afraid. I finally figured out, after lots of trial and error, that I had to set the option Surround Jack Mode in the Gnome Mixer to the value Independent to get the mic working. Skype seems to be working fine now. Next challenge will be to find a web cam that works…

For your reference, here’s the full output I get when running amixer: Continue reading