On 15.07.2011 04:19, Kevan Miller wrote: > From time to time I encounter a problem starting a Geronimo server on a Linux > system (I've always seen it on Ubuntu -- but the problem could exist on other > distributions). The server start seems to hang. However, if you're patient, > which I rarely am, the server will eventually start. If you're inquisitive, > and dump the stack traces of the java process, you'll see something like: > > "main" prio=10 tid=0x0000000040c0d800 nid=0xa79 runnable [0x00007f57a04fb000] > java.lang.Thread.State: RUNNABLE > at java.io.FileInputStream.readBytes(Native Method) > at java.io.FileInputStream.read(FileInputStream.java:220) > at > sun.security.provider.NativePRNG$RandomIO.readFully(NativePRNG.java:185) > at > sun.security.provider.NativePRNG$RandomIO.implGenerateSeed(NativePRNG.java:202) > - locked <0x00000000daad63e0> (a java.lang.Object) > at > sun.security.provider.NativePRNG$RandomIO.access$300(NativePRNG.java:108) > at > sun.security.provider.NativePRNG.engineGenerateSeed(NativePRNG.java:102) > at java.security.SecureRandom.generateSeed(SecureRandom.java:495) > at > com.sun.net.ssl.internal.pkcs12.PKCS12KeyStore.getSalt(PKCS12KeyStore.java:477) > at > com.sun.net.ssl.internal.pkcs12.PKCS12KeyStore.calculateMac(PKCS12KeyStore.java:834) > at > com.sun.net.ssl.internal.pkcs12.PKCS12KeyStore.engineStore(PKCS12KeyStore.java:788) > - locked <0x00000000d3b5a768> (a > com.sun.net.ssl.internal.pkcs12.PKCS12KeyStore) > at java.security.KeyStore.store(KeyStore.java:1117) > ... > > This problem isn't Geronimo specific. But since I see it from time to time, > thought it would be worth passing along to the community... > > The Sun/Oracle-based JVM is attempting to generate a pseudo-random number to > be used as a seed for an SSL server socket. To generate the pseudo-random > number, the JVM is reading from the /dev/random device to obtain some random > information for the seed. The problem is that reads from the /dev/random > device will block if the system does not have a good source of random events. > So, the Geronimo server startup is blocked waiting for enough random > information to be returned from /dev/random. This article may be help > understand the basic issue -- http://en.wikipedia.org/wiki//dev/random#Linux > > I'm no security expert. And I don't know the potential implications, but the > simplest way that I've found to avoid the problem is to use the /dev/urandom > device, instead of /dev/random. Do this by specifying the following java > property '-Djava.security.egd=file:/dev/./urandom'. So, the following should > work well: > > $ GERONIMO_OPTS="-Djava.security.egd=file:/dev/./urandom" ./geronimo run > --long > > Note to self -- would be nice to record this on our Wiki somewhere. Anyway, > hope this is useful...
And note that due to a bug in the JDK you really need to use /dev/./urandom or /dev//urandom and not /dev/urandom. Oracle themselves already internally use "dev/urandom, but later they switch from /dev/urandom to /dev/random if the setting is trsingwise identical to /dev/random. That's why you need to use some different string that's equivalent to /dev/urandom after path normalization. We had the same problem for Tomcat, mostly when starting two instances in parallel. Regards, Rainer
