Optimizing performance-critical parameters

Some performance-critical parameters changed to more comfortable
for production environments.

Restoring missing ones from original patch:
Original Change-id: Ibfb81279892303166dbafe9f1cdc87927c0fe9a0

Change-Id: Ie95c6438c01a17b37a9b88d1eb0819f0eee2be02
Merge "Optimizing performance-critical parameters" into stable/5.1