https://www.odoo.com/documentation/10.0/setup/deploy.html#builtin-server 

Odoo includes built-in HTTP servers, using either multithreading or multiprocessing.

For production use, it is recommended to use the multiprocessing server as it increases stability, makes somewhat better use of computing resources and can be better monitored and resource-restricted.

• Multiprocessing is enabled by configuring a non-zero number of worker processes, the number of workers should be based on the number of cores in the machine (possibly with some room for cron workers depending on how much cron work is predicted)

• Worker limits can be configured based on the hardware configuration to avoid resources exhaustion