Durable Execution Engine¶

The durable execution engine (dex) handles background task scheduling and execution. This page documents its worker types, task queues, and default configuration.

For tuning guidance, see Scaling.

Workers¶

Workers poll task queues and execute tasks. Each worker has a configurable maximum concurrency that limits how many tasks it processes simultaneously per instance.

Worker concurrency is configured via:

dt.dex-engine.<worker-type>.<worker-name>.max-concurrency=<N>

Where <worker-type> is either workflow-worker or activity-worker.

Worker Type	Worker Name	Queue	Default Concurrency
`workflow-worker`	`default`	`default`	100
`activity-worker`	`default`	`default`	25
`activity-worker`	`vuln-analysis`	`vuln-analyses`	10
`activity-worker`	`artifact-import`	`artifact-imports`	10
`activity-worker`	`package-metadata-resolution`	`package-metadata-resolutions`	10
`activity-worker`	`notification`	`notifications`	5
`activity-worker`	`vuln-analysis-reconciliation`	`vuln-analysis-reconciliations`	5
`activity-worker`	`policy-evaluation`	`policy-evaluations`	5
`activity-worker`	`metrics-update`	`metrics-updates`	5

Task queues¶

Task queue capacity limits how many tasks can be pending across the entire cluster. When a queue reaches capacity, the scheduler stops creating new tasks for that queue, providing backpressure.

Queue capacity is modifiable at runtime in the administrator panel under Workflows -> Task Queues, or via REST API.

Type	Queue	Default Capacity
`workflow`	`default`	1000
`activity`	`default`	1000
`activity`	`artifact-imports`	25
`activity`	`metrics-updates`	25
`activity`	`notifications`	25
`activity`	`package-metadata-resolutions`	25
`activity`	`policy-evaluations`	25
`activity`	`vuln-analyses`	25
`activity`	`vuln-analysis-reconciliations`	25