Signed-off-by: Ahmed Hussein (amahussein) <[email protected]>

Fixes NVIDIA#943

This code change is to reduce the probability of OOME thrown by the core-tools when too many threads are created within the core module.
The problem was that a thread processing the eventlog would need around
4-6 GB to succeed. This PR is aiming at dynamically calculating the number of threads that can fit to the virtual memory of the host.
Note that this does not solve the problem. It is an improvement to dynamically pass JVM resources to the java cmd.
Again, an OOME can be thrown if the batch of eventlogs is too large to
exceed the expected 8 GB scenario.

What has changed:

- Use G1GC as GC algorithm. this is to override the default JDK8 parallel GC. The G1GC which stands for Garbage-First GC could be a better option to target short living objects.
- Pull the Virtual memory information of the host machine to calculate the default heap size. By default the heap size is set to 80% of the total virtual memory.
- Next, calculate the number of threads to be passed to the RAPIDS java cmd. Assuming that a thread needs at least 8GB of heap memory. the number of threads is calculated at (`heap_size / 8`)
- If the CLI is running in concurrent mode (i.e., estimation_model is enabled), then the CLI splits the resources between Profiling and Qualification by the ratio of 2:1 respectively.
- Add `jvm_heap_size` to the `spark_rapids` CLI

Signed-off-by: Ahmed Hussein (amahussein) <[email protected]>

Signed-off-by: Ahmed Hussein (amahussein) <[email protected]>

Signed-off-by: Ahmed Hussein (amahussein) <[email protected]>