I installed latest Logstash (2.4) on my linux mint 17. Created a conf file and tried starting it. It gives me a very huge stack trace (1740 lines of stack trace).

LoadError: Could not load FFI Provider: (NotImplementedError) FFI not available: java.lang.UnsatisfiedLinkError: could not locate stub library in jar file.  Tried [jni/x86_64-Linux/libjffi-१.२.so, /jni/x86_64-Linux/libjffi-१.२.so]
        at com.kenai.jffi.internal.StubLoader.getStubLibraryStream(StubLoader.java:396)
        at com.kenai.jffi.internal.StubLoader.loadFromJar(StubLoader.java:345)
        at com.kenai.jffi.internal.StubLoader.load(StubLoader.java:254)
        at com.kenai.jffi.internal.StubLoader.(StubLoader.java:434)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:348)
        at com.kenai.jffi.Init.load(Init.java:68)
        at com.kenai.jffi.Foreign$InstanceHolder.getInstanceHolder(Foreign.java:49)
        at com.kenai.jffi.Foreign$InstanceHolder.(Foreign.java:45)
        at com.kenai.jffi.Foreign.getInstance(Foreign.java:103)
        at com.kenai.jffi.Platform.isSupported(Platform.java:370)

I am reproducing above, first few lines of stack trace.

Some part of the stack trace (added below here) seems to suggest, it got something to do with jruby.

java.lang.UnsatisfiedLinkError: Can't load library: /usr/java/packages/lib/amd64/libjffi-१.२.so
    at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1827)
    at java.lang.Runtime.load0(Runtime.java:809)
    at java.lang.System.load(System.java:1086)
    at com.kenai.jffi.internal.StubLoader.loadFromBootPath(StubLoader.java:316)
    at com.kenai.jffi.internal.StubLoader.load(StubLoader.java:249)
    at com.kenai.jffi.internal.StubLoader.(StubLoader.java:434)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:348)

Any clues or recommendations on how to proceed to fix this..?

As shown in the 2nd stack trace above, my m/c doesn't have a directory /usr/java/..., so its obviously failing. But I don't understand why it will look for /usr/java/... set of folders.

Some other part of stack trace shows it is unable to locate libjffi-1.2.so.

What do all these errors mean, and how to fix ?