Odoo server sizing: how many workers and how much RAM?

Workers, threads and cron

Odoo can run in threaded mode (workers = 0), where one process handles everything, or in multi-process mode, where a number of worker processes handle HTTP requests in parallel. Production servers should always use multi-process mode. Scheduled actions run in separate cron processes, set by max_cron_threads (2 by default).

How many workers?

Odoo's deployment documentation gives two rules of thumb:

• CPU: up to (CPU cores × 2) + 1 workers.
• Users: one worker serves about six concurrent users.

Use the lower of the two. Ten people logged in at once rarely need more than three workers, even on a large server.

How much RAM?

Odoo's documentation estimates that about 80% of requests are light (around 150 MB) and 20% are heavy (around 1 GB). That averages to roughly 325 MB per worker. On top of that, leave room for cron processes, PostgreSQL and the operating system.

Memory and time limits

In multi-process mode, Odoo recycles a worker that grows past limit_memory_soft once its current request finishes, and kills it immediately at limit_memory_hard. Time limits (limit_time_cpu and limit_time_real) stop runaway requests. Set the memory limits so all workers and cron processes together cannot exhaust RAM.

CloudPilot calculates these for you. It shares about 70% of the server's RAM between workers and cron processes, leaving the rest for PostgreSQL and the OS, and clamps the result to Odoo's defaults (2 GB soft, 2.5 GB hard) with a 256 MB floor. The hard limit is 25% above the soft limit.

PostgreSQL on the same server

Most Odoo servers run PostgreSQL on the same machine, so its memory settings should be more modest than on a dedicated database server. CloudPilot's PostgreSQL tuning uses:

• shared_buffers: about 15% of RAM (rather than the usual 25%), between 128 MB and 8 GB
• effective_cache_size: about 50% of RAM
• work_mem: RAM ÷ 256, between 4 MB and 64 MB
• maintenance_work_mem: RAM ÷ 16, up to 2 GB
• random_page_cost = 1.1, suited to SSD storage

Sizing table

Worked numbers using (CPU × 2) + 1 workers, two cron threads and the formulas above. Treat them as a starting point, then adjust using real traffic.

Signs your server is the wrong size

• Requests queue at busy times but CPU is low: add workers, if memory allows.
• Workers are killed for memory in the logs: lower the worker count or add RAM.
• CPU sits at 100%: you have more workers than cores can serve. Move to a bigger server.
• Slow reports and list views with free CPU and RAM: look at PostgreSQL, missing indexes and custom code.

For a step-by-step diagnosis, see why Odoo is slow: 10 causes and fixes.

CloudPilot's monitoring shows CPU, memory and disk per server and alerts you before users notice. Change the worker count on an instance and the memory limits are recalculated automatically.

CloudPilot applies these settings for you on Odoo Community hosting and managed Odoo hosting. The underlying options are described in Odoo's deployment documentation.

Frequently asked questions