High performance drop in master vs 2.7

Builds under test:

• Apache Ignite from branch master, nightly build at 2019-02-15
• Apache Ignite 2.7

Benchmark:

• atomic put-all (IgnitePutAllBenchmark), batch size: 100

Environment:

• 4 servers, 8 clients (64 threads)
• In-memory mode (the drop is not as high when persistence is enabled)

Results for FULL_SYNC (-16.19% drop in master):

Results for PRIMARY_SYNC (-23.41% drop in master):