ZeroMQ Java example hangs on Ubuntu 12

Question

I'm trying to program with ZeroMQ on Ubuntu using the Java examples. I've successfully built ZeroMq core and Java bindings, but trying to run simple example, it just hangs indefinitely.

Here's what I've done so far, btw, I'm using JDK/JRE 1.7, ZeroMQ 3.2.2, and Ubuntu 12.10 64-bit

Build ZeroMQ Core Libraries

I downloaded core ZeroMQ 3.2.2 POSIX tarball from here, extracted and built according to instructions here. Configure, make, and installation all went well, no errors, I also ran ldconfig following make to update the system library cache. A quick look at /usr/local/lib and the core libraries appear to have built correctly...

usr1@ubuntu:/usr/local/lib$ ls -ltr *.so
lrwxrwxrwx 1 root dev 15 Apr  1 19:31 libzmq.so -> libzmq.so.3.0.0
lrwxrwxrwx 1 root dev 16 Apr  1 20:14 libjzmq.so -> libjzmq.so.0.0.0

Build JZMQ Java Bindings

Downloaded Java bindings source from here, configured, ran make; all looks good. This creates zmq.jar and zmq-perf.jar; ran ldconfig again to update library cache; moved jars to /usr/local/share/java...

usr1@ubuntu:/usr/local/share/java$ ls -ltr
-rw-r--r-- 1 usr1 usr1 40507 Apr  1 20:14 zmq.jar
-rw-rw-r-- 1 usr1 usr1  4809 Apr  2 08:41 zmq-perf.jar

Running Example local_lat

I ran the local_lat example detailed here using the following settings for my environment...

java -Djava.library.path=/usr/local/lib -classpath /usr/local/share/java/zmq-perf.jar:/usr/local/share/java/zmq.jar local_lat tcp://127.0.0.1:5555 1 100

Got UnsatisfiedLinkError; fixed that by just logging in and out. Ran again and it just hangs, no errors, nata, zilch. I removed the argument 100 from above and got the usage message from local_lat, so I know it's finding the zmq jar files since local_lat class resides in zmq-perf.jar. Ran again with the above command, and it just hangs; no errors, nothing. A bit of a let down since it was quite a bit of work to get everything built.

UPDATE

See below, turns out this was a problem with how I was testing

Answer 1

Ok, so it turns out everything I did was correct. The core libs and Java bindings were built and installed successfully, the problem was the example...

java -Djava.library.path=/usr/local/lib -classpath /usr/local/share/java/zmq-perf.jar:/usr/local/share/java/zmq.jar local_lat tcp://127.0.0.1:5555 1 100

The local_lat program is not a Hello World test, I thought it was, it's a bit misleading on the jzmq site, the above is a command line example, not an example to test the installation, and that was confirmed by looking at the code for local_lat; it doesn't do anything, and certainly does not output anything which is why it appeared to just hang.

I tested ZeroMq with this code, downloaded and javac'ed it, used the above command to run it.