Study Lab
local appVango

State Machine Gallery

Every meaningful mutation should have durable stages, gates, and known failure modes.

Deploy Pipeline

Control plane operation

state machine
queuedcloningbuildingvalidatingpreview_readyblockedfailed

Gates

generated artifacts current
Vango state impact classified
DB impact classified
secrets/providers bound

Failure modes

stale artifacts
build digest mismatch
cold deploy needs approval
migration blocks preview

Production Promotion

Promotion operation

state machine
requestedpolicy_checkroute_casedge_propagatinghealthyrolled_backfailed

Gates

preview artifact exactly matches
route epoch predecessor current
approval present if required
runtime services ready

Failure modes

late worker report
route epoch conflict
edge replay gap
DB rollback unsafe

Wake

Regional data plane

state machine
coldwake_requestedstartingreadiness_waithotfailedsleeping

Gates

request class safe to hold
wake budget available
allocation passes readiness
unsafe replay policy exists

Failure modes

payment webhook while cold
wake stampede
readiness timeout
old route epoch

Allocation Lifecycle

Scheduler and runner

state machine
plannedpullingstartingreadydrainingstoppedfailed

Gates

artifact digest verified
env/secrets mounted
health/readiness pass
drain deadline respected

Failure modes

runner crash
secret missing
OOM
session still active at drain deadline

Host Drain / OS Upgrade

Operations

state machine
cordonedevacuatingreplacement_readyupgradingpostcheckuncordoned

Gates

quorum remains healthy
runner headroom exists
active sessions can drain
drift checks pass

Failure modes

no headroom
active sessions pinned
provider outage
runner-agent regression

Region Enablement

Platform topology

state machine
requestedprovisioningbinding_servicesreplicating_artifactseligibledisabled

Gates

data topology ready
runtime services available
secrets present
residency allowed

Failure modes

artifact absent
DB not replicated
session store missing
residency policy violation

Database Migration

Pipeline/data operation

state machine
classifieddry_runlockedapplyingverifiedblockedfailed

Gates

expand/contract safe
backup/PITR posture known
old artifact compatibility checked
rollback plan explicit

Failure modes

destructive migration
old app incompatible
preview mutates production
manual lock timeout