The built-in multiprocess mode is new in v7, and mostly replaces the previous gunicorn-based multiprocess mode of v6.1. It has the same kind of features as v6.1's gunicorn settings, as shown by openerp-server --help:

$ ./openerp-server --help

Usage: openerp-server [options]

Options:
  --version             show program's version number and exit
  -h, --help            show this help message and exit

  (...)

  Multiprocessing options:
    --workers=WORKERS   Specify the number of workers, 0 disable prefork mode.
    --limit-memory-soft=LIMIT_MEMORY_SOFT
                        Maximum allowed virtual memory per worker, when
                        reached the worker be reset after the current request
                        (default 671088640 aka 640MB).
    --limit-memory-hard=LIMIT_MEMORY_HARD
                        Maximum allowed virtual memory per worker, when
                        reached, any memory allocation will fail (default
                        805306368 aka 768MB).
    --limit-time-cpu=LIMIT_TIME_CPU
                        Maximum allowed CPU time per request (default 60).
    --limit-time-real=LIMIT_TIME_REAL
                        Maximum allowed Real time per request (default 120).
    --limit-request=LIMIT_REQUEST
                        Maximum number of request to be processed per worker
                        (default 8192).

This new built-in multi-process HTTP Server (nicknamed MultiCorn - pun on Unicorn intended) makes deployment easier while reusing the same design principles as Gunicorn: a WSGI-compliant HTTP server with pre-forked worker processes.

It adds a few niceties on top of what was already possible with Gunicorn in v6.1, such as:

• No need to run and manage separately another OpenERP process for executing background OpenERP jobs (ir.cron). MultiCorn spawns a dedicated CronWorker automatically (controlled by --max-cron-threads)
• The WSGI entry point is now openerp.service.wsgi_server.application (it was openerp.wsgi.application in v6.1), but v7.0 has a new openerp-wsgi.py startup script to make deploying in WSGI containers easier

All the ideas behind the introduction of the multi-process mode in v6.1 still apply.