Another possibility to fix it is to install rng-tools which will allow you to increase the amount of entropy in your system. -- Take care, Konstantin (Cos) Boudnik
On Mon, Jan 3, 2011 at 16:48, Jon Lederman <[email protected]> wrote: > Thanks. Will try that. One final question, based on the jstack output I > sent, is it obvious that the system is blocked due to the behavior of > /dev/random? That is, can you enlighten me to the output I sent that > explicitly or implicitly indicates the blocking? I am trying to understand > whether this is in fact the problem or whether there could be some other > issue. > > If I just let the FS command run (i.e., hadoop fs -ls), is there any > guarantee it will eventually return in some relatively finite period of time > such as hours, or could it potentially take days, weeks, years or eternity? > > Thanks in advance. > > -Jon > On Jan 3, 2011, at 4:41 PM, Ted Dunning wrote: > >> try >> >> dd if=/dev/random bs=1 count=100 of=/dev/null >> >> This will likely hang for a long time. >> >> There is no way that I know of to change the behavior of /dev/random except >> by changing the file itself to point to a different minor device. That >> would be very bad form. >> >> One think you may be able do is to pour lots of entropy into the system via >> /dev/urandom. I was not able to demonstrate this, though, when I just tried >> that. It would be nice if there were a config variable to set that would >> change this behavior, but right now, a code change is required (AFAIK). >> >> Another thing to do is replace the use of SecureRandom with a version that >> uses /dev/urandom. That is the point of the code that I linked to. It >> provides a plugin replacement that will not block. >> >> On Mon, Jan 3, 2011 at 4:31 PM, Jon Lederman <[email protected]> wrote: >> >>> >>> Could you give me a bit more information on how I can overcome this issue. >>> I am running Hadoop on an embedded processor and networking is turned off >>> to the embedded processor. Is there a quick way to check whether this is in >>> fact blocking on my system? And, are there some variables or configuration >>> options I can set to avoid any potential blocking behavior? >>> >>> > >
