Recorder thread blocks when writing to file

[hrosa]

Profiling a load test of recording scenario, with 20 calls per second and 250 concurrent calls, I noticed the scheduler threads tend to block 4-7ms when writing to file.

We should optimize this behaviour and possibly move from blocking FileChannel to https://docs.oracle.com/javase/7/docs/api/java/nio/channels/AsynchronousFileChannel.html

[jaimecasero]

Apart from moing into a non-blocking API, we may consider an integration solution, "rather than code", by using SDD disk, or memory partition.

SDD disks provides much better performance for writes, specially smallChunked/random writes.

If total disk size for recordings is not too high, we may consider a memory partition ( hopefully replicated into disk asynchronously) to speed up the writes...

[jaimecasero]

nice answer on linux disk tuning
http://unix.stackexchange.com/questions/30286/can-i-configure-my-linux-system-for-more-aggressive-file-system-caching

[hrosa]

should have been fixed by #200
Need to redo some tests.