Re: OpenCV + Spark : Where to put System.loadLibrary ?

[Tobias Pfeiffer]

Hi,

please see this post:


http://apache-spark-user-list.1001560.n3.nabble.com/Keep-state-inside-map-function-tp10968p11009.html

Where it says "some setup code here", you could add your code to load the
library. Note, however, that this is not once per node, but once per
partition, so it might be called more than once on each node.

If you want to have setup code that is run once per node, put it in a Scala
"object" (as Matei pointed out back then). For example:

    object JvmLocalResource {
      val resource = {
        someInitFunction()
        new SomeResource()
      }
    }

Now if you use JvmLocalResource.resource, the someInitFunction() will be
called exactly once on each node (in each JVM). If the library loading is
synchronous (i.e., doesn't start some fancy background action that is not
finished yet when you want to start processing), that should do it.

Tobias