Skip to main content
The VM pool is why agents start in seconds, not minutes. The platform maintains pre-booted VMs ready for instant assignment. When you spawn an agent, it claims a warm VM immediately instead of waiting for a cold boot.

How the pool works

The platform continuously maintains a set of warm VMs:
  1. Backfill — when idle VMs drop below the workspace’s min_idle threshold, new ones are booted
  2. Assignment — when you spawn an agent, a warm VM is claimed instantly
  3. Hard cap — total VMs never exceed max_vms (set in pool-config)

Pool configuration

Each tenant has a pool-config resource (singleton, always named default) that sets the tenant-wide max_vms cap. Each workspace has a min_idle field that controls how many warm VMs to keep ready for that workspace. Monitor pool health with murmur pool status. After changing environment config or images, use murmur pool flush to drain warm VMs so fresh ones are created from the new configuration.

Cost management

Warm VMs consume compute even when idle. Tune these parameters to balance speed vs cost:
ParameterTrade-off
Higher min_idleFaster agent startup, higher idle cost
Lower min_idleSlower startup (may need cold boot), lower idle cost
Lower max_vmsHard cost cap, but may queue agent starts during peaks
A min_idle of 1–3 is a good starting point for most teams.
TypePage
Referencepool-config
Referencemurmur pool status
Referencemurmur pool up
Referencemurmur pool flush
ConceptWorkspaces
ConceptEnvironments