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Queues

Download and build queue controls — pause/resume, reorder, parallelism, speed limits, and schedules.

OPAL runs long operations through two queues: one for downloads (engines, gems, assets) and one for builds (engine source builds, project builds). They share a common look and feel — add, pause, resume, reorder, cancel — and both surface live status in the status bar at the bottom of the window.

The queues are built to survive interruption: close OPAL mid-operation and reopen later, and the queue is intact.

In this section

  • Downloads — Pause/resume, reorder, cap concurrency, throttle bandwidth, and schedule download windows.
  • Builds — Queue, pause/resume, cancel, reorder, and view build logs.
  • Status bar — The bottom-bar widgets and drawers that show queues at a glance.
← Previous: Assets & Gems Next: Logs →

1 - Downloads

Pause/resume, reorder, cap concurrency, throttle bandwidth, and schedule download windows.

The Downloads queue handles engine installers, gems, and other assets. Each item shows its progress; a backend download manager (written in Rust) does the actual work, so pausing, resuming, and resuming-after-a-crash all behave properly rather than silently restarting.

Per-item controls

  • Pause / Resume an individual download.
  • Cancel a download.
  • Move to Top or drag to reorder the queue. OPAL is careful here: if a non-pausable active item is dragged down it snaps back, and if “move to top” has no pausable item to demote, OPAL tells you rather than doing nothing.
  • Cancel & Requeue — offered for a non-pausable download that’s still running past a scheduled window’s close.

Whole-queue controls

  • Pause All / Resume All toggles the entire download queue.
  • Clear Completed clears finished items from the list.

Concurrency

Set how much runs at once in Settings:

  • Max concurrent downloads — how many downloads run simultaneously (default 3; 0 = unlimited).
  • Max connections per download — parallel connections for a single download (default 3, up to 16).

Speed limits

Enable a global download throttle and set the limit with a unit (Mb/s or Kb/s). Off by default — turn it on when OPAL is competing with a call or a metered connection.

Scheduled windows

Restrict downloads to a time window (for example 22:00–07:00). When the window closes, OPAL pauses the queue; when it opens, OPAL resumes automatically. Windows that cross midnight are handled correctly. Configure the window in Settings.

Credentials

If a download needs git authentication (for a gem source clone or LFS fetch), a secure credential prompt handles it. See Repositories & sources.

See also

2 - Builds

Queue, pause/resume, cancel, reorder, and view build logs.

The Builds queue handles engine source builds and project builds. Like downloads, each build shows progress and can be managed while it runs — and its output is always a click away in the log viewer.

Per-item controls

  • Pause / Resume an individual build.
  • Cancel a build. Cancelling also stops the child build processes it spawned, so nothing is left running in the background.
  • Move to Top or drag to reorder, with the same smart demote / no-victim notifications as the downloads queue.
  • View Log streams the build’s output into the shared Logs viewer.

Whole-queue controls

  • Clear Completed clears finished builds from the list.

Concurrency

Set max concurrent builds in Settings (default 1). O3DE builds are memory-hungry, so 1 is a sensible default on a laptop; workstations can run more. Build parallelism (thread count) is set separately in Build Tools settings.

See also

3 - Status Bar

The bottom-bar widgets and drawers that show queues at a glance.

The status bar runs along the bottom of the OPAL window. It’s driven by a widget registry, so it shows compact, live indicators for background work without you needing to open a full page.

Widgets

Out of the box the status bar carries Downloads and Builds widgets. A widget can show an icon, label, count, and a progress bar, and can be aligned to the left, centre, or right of the bar. The default queue widgets are centre-aligned.

Drawers

Click a queue widget to open a drawer that slides up from the bottom, showing the live queue for that widget without leaving the page you’re on. From the drawer, a button jumps to the full Downloads or Builds page when you want the complete view and controls.

See also