Re: swingbench connection issue

From: De DBA <>
Date: Wed, 14 Nov 2012 15:01:26 +1000
Message-ID: <>


I don't know charbench, or how it uses randomness, but perhaps this may go some way to explaining it:

(quote from )

"...When the entropy pool is empty, reads to /dev/random will block until additional environmental noise is gathered."

( from wikipedia )
"... A counterpart to /dev/random is /dev/urandom ("unlocked"/non-blocking random source[4]) which reuses the internal pool to produce more pseudo-random bits. This means that the call will not block, but the output may contain less entropy than the corresponding read from /dev/random. "

As I understand it, at some point on the one database you could have exhausted the entropy pool and the process blocks until some more entropy is gathered? Perhaps due to better performance on that one database than the other, or different test data settings?

Usn/Martin Klier also has some suggestions on his blog on how to ensure that Oracle JDBC won't exhaust the entropy on a server:


On 13/11/12 4:17 PM, kyle Hailey wrote:
> This seems to have solved it
> *rm /dev/random*
> *ln -s /dev/urandom /dev/random
> *strange that the problem arises with one database on the box but not
> another on the same box
> --

Received on Wed Nov 14 2012 - 06:01:26 CET

Original text of this message