Scheduled Events And Queues

A Rewrite Must Restate the Queue

create or modify microflow rebuilds the microflow from the statement, so a binding the script does not restate is gone. mxcli refuses rather than drop it:

Error: microflow Ops.ACT_Caller has 1 call(s) bound to a task queue that this
script does not restate (Ops.MyQueue), and rewriting it would silently drop the
binding.

Add in queue Ops.MyQueue to the call and the rewrite goes through. Without the refusal the binding was written back as null and the project then looked healthier than before — mx check stopped reporting CE1613, because the configuration the error was about had been deleted.

One thing is still refused: a retry policy on a queued call (Queues$QueueFixedRetry / Queues$QueueExponentialRetry). MDL has no syntax for it, so a rewrite cannot preserve it — change that microflow in Studio Pro.

When a Java Action Is the Better Tool

The activity property gives queueing and nothing else. The runtime API, reachable from a Java action, gives queueing and retry, and can queue a Java action directly with no wrapper microflow:

Core.userActionCall("Ops.RefreshData")
    .withParams(url)
    .withExponentialRetry(5, Duration.ofSeconds(2), Duration.ofMinutes(2))
    .executeInBackground(ctx, "Ops.OrderProcessing");

Use Core.microflowCall(...) when the unit of work really is a microflow.

Placing Them in Folders

Both take a folder clause on create, straight after the qualified name:

mdl 1;
create scheduled event Ops.SE_Nightly folder 'Private/Scheduled events'
  ( Microflow: Ops.ACT_Nightly, Repeat: Daily, StartDateTime: '2026-01-01T02:00:00Z' );

create task queue Ops.Q_Imports folder 'Private/Queues' ( Parallelism: 3 );

On create or modify the clause moves an existing document; omitting it leaves placement alone. See organize-project.

Validation Checklist

Before presenting a script:

mxcli check script.mdl                       # catches wrong-repeat fields (MDL-SCHED01)
mxcli check script.mdl -p app.mpr --references

• Every scheduled event has Microflow and Repeat
• Only that repeat's fields are used
• Enabled: true if it is meant to run
• Enum values spelled exactly (Server, DelayNext, Last, Monday)
• The target microflow exists and takes no parameters

Querying and Linting

Both document types are in the catalog after refresh catalog:

-- Anything that fires more often than once a minute
select QualifiedName, RepeatDescription, Microflow
from CATALOG.SCHEDULED_EVENTS
where Enabled = 1 and IntervalSeconds < 60;

select QualifiedName, Parallelism, ClusterWide from CATALOG.QUEUES;

A scheduled event counts as a caller of the microflow it runs, so list callers of Ops.SE_Cleanup lists it and the lint rule for orphaned microflows (QUAL004) does not flag it. IntervalSeconds is derived from the schedule, not from the legacy Interval/IntervalType pair Mendix also stores.

Starlark lint rules can iterate both: scheduled_events() yields repeat, interval_seconds, on_overlap, time_zone, enabled, and microflow_name; queues() yields parallelism (a string) and cluster_wide.

Related

• mxcli syntax scheduled-event, mxcli syntax queue — full syntax reference
• write-microflows — writing the microflow the event calls
• project-settings — after-startup / before-shutdown microflows

Scheduled events — Mendix's cron (LIST/DESCRIBE/CREATE [OR MODIFY]/DROP). Repeat: names one of the eight ScheduledEvents$*Schedule variants and only that variant's fields are accepted; a field from another repeat is refused by mxcli check (MDL-SCHED01) and by exec, which call the same function. The document shape is pinned by re-serializing three whole Studio Pro-authored events (Workflow Commons 4.11.0, OIDC SSO 4.6.0, SAML 4.2.1) element by element — modelsdk/gen is wrong about two properties here

the integers are stored as int64 (gen says int32, the #585 mismatch) and StartDateTime is a BSON datetime (gen says string), so both engines share one raw-BSON codec in mdl/scheduledevents. Interval/IntervalType are legacy siblings of Schedule that Studio Pro writes and does not keep in sync — derived on CREATE, carried through untouched on MODIFY. Only the Day and Hour variants have a Studio Pro reference; the other six are metamodel-derived and verified to load. Both are in the catalog (CATALOG.SCHEDULED_EVENTS, CATALOG.QUEUES) and a scheduled event emits a schedule edge into CATALOG.REFS — without it a microflow run only by a scheduled event was reported as dead by list callers, GRAPH_DEAD_ASSETS and lint rule QUAL004.

Task queues (LIST/DESCRIBE/CREATE [OR MODIFY]/DROP TASK QUEUE). Config.ParallelismExpression is a string and the sibling int32 Parallelism is not written — matching all four Studio Pro queues in Business Events 3.12.1. Binding a call to a queue is not yet authorable, so CREATE OR REPLACE|MODIFY MICROFLOW is refused when the stored microflow has a queued call (guard-don't-drop, ADR-0005)

the rebuild used to write QueueSettings back as null, which made mx check go from CE1613 to 0 errors by deleting the user's configuration