Cluster and workload management
Cluster pools, clusters, and queues are managed through the flyte
CLI and are configured by your platform administrator. The commands on these
pages are administrative operations — most workflow authors only need
task-side queue routing.
flyteplugins-union pluginThe flyte cluster, pool, and queue commands on these pages are provided by the
flyteplugins-union package. Install it with pip install flyteplugins-union.
As a Union.ai deployment grows past a single cluster, you need a way to decide where a workload runs and under what limits. Three primitives work together to make that decision explicit and safe:
- Cluster pool — an org-level isolation boundary. Both the clusters and the queues inside a pool share one data-plane configuration: the same object store, secret store, and container registry. Anything Union.ai uploads for a run (inputs, code bundles, secrets) is reachable from every cluster in the same pool — and from no cluster outside it. Pools do not connect: you cannot move a workload directly from one pool to another (see Crossing a pool boundary).
- Cluster — an execution cluster that lives in exactly one pool.
- Queue — what users actually submit to. A queue lives inside one pool and routes work to one or more clusters in that pool, carrying the concurrency, depth, priority, and fairness limits applied to the work it admits.
How they fit together
flowchart TD
Org["Organization"]
Org --> PD
Org --> PP
subgraph PD["Cluster pool: default"]
direction TB
QD["Queue: default<br/>(any project/domain)"]
CA["Cluster A"]
CB["Cluster B"]
QD --> CA
QD --> CB
end
subgraph PP["Cluster pool: prod"]
direction TB
QP["Queue: prod-queue<br/>(myproj / production)"]
CC["Cluster C"]
CD["Cluster D"]
QP --> CC
QP --> CD
end
A cluster pool is an isolation boundary: both clusters and queues live inside a pool, and everything in it shares one data plane. A queue routes work to one or more clusters in its own pool — the platform picks any healthy cluster in the pool (or the specific clusters you pin it to).
The key invariant: a queue can never reach a cluster outside its pool, because a run’s inputs, code, and secrets are uploaded to that pool’s data plane and no other pool’s clusters can read them. That is what makes a pool an isolation boundary.
Crossing a pool boundary
Because pools don’t share a data plane, they don’t connect. You cannot move a run, a queue, or a cluster from one pool to another in place. Crossing a pool boundary means physically re-landing the workload in the destination pool’s data plane — moving its data, containers (images), code, and secrets into the new pool’s object store, registry, and secret store. This is deliberate friction: it keeps in-flight work from ever pointing at storage it can’t read, and it’s why pool changes are rare and explicit (a queue’s pool change requires a drain).
Every organization is provisioned with a default pool that all clusters join
automatically. If you run a single cluster — or several clusters that share one
bucket, secret store, and registry — you never need to think about pools. Your
cluster lands in default, queues route to default, and you can skip straight
to
Queues. Pools only matter once you have clusters with distinct
data planes (for example, separate dev and prod cloud accounts).
In this section
default pool if you only have one.