567cdd1a15 feat(playback): balance transcode sessions across multiple GPUs (#425)
* feat(playback): balance transcode sessions across multiple GPUs

playback.hw_device now accepts a comma-separated render-device list (e.g.
"/dev/dri/renderD128,/dev/dri/renderD129"). Each transcode session resolves
the list to one concrete device at spawn — the present device with the
fewest active GPU sessions, ties keeping list order — and holds that device
for its whole lifetime (seek/audio restarts reuse it); the reservation
releases on session shutdown, idempotently, including early spawn-failure
paths. Software-accel sessions never reserve, so they cannot skew the
balance.

A single configured value keeps the historical pass-through contract and an
empty value still auto-detects, so existing deployments are unaffected.
PickRenderDevice is list-aware too, picking least-loaded without reserving,
which lets the non-session consumers (chapter thumbnails, download
artifacts, transcode nodes) spread load best-effort when given a list.

Motivation: hosts with two identical media GPUs (e.g. dual Arc A310)
previously pinned every session to one device while the second sat idle.

* feat(admin): GPU device picker for playback hw_device

The hw-accel detection endpoint now reports render_device_details — each
render device with a human label derived from its sysfs PCI vendor/device
ids ("Intel GPU (0x56a6)") — and the Playback settings page renders them as
per-device toggles instead of requiring a hand-typed device path. No
selection means auto (first available device); one selection pins every
session; multiple selections balance least-loaded. The stored
playback.hw_device value stays the comma-separated list, written in stable
detection order regardless of click order, and a configured-but-undetected
device stays visible so a temporarily missing GPU is not silently dropped
on save.

* fix(playback): make GPU selection and reservation atomic

Review follow-up: resolveSessionHWDevice previously selected the
least-loaded device and incremented its count in two separate critical
sections, so concurrent session starts could all pick the same device
before any reservation landed. Device presence checks now happen outside
the lock and selection + reservation share one critical section; a
concurrency test asserts an exact split across two devices for eight
simultaneous starts, which the two-step version cannot guarantee.

* refactor(playback): one typed GPU acquisition boundary, release on process exit

Replace the CSV-handling spread across resolveSessionHWDevice and
PickRenderDevice with HWDeviceSet + AcquireHWDevice in hwdevice.go: every
GPU workload resolves exactly one device immediately before spawn.
Balancing is explicitly QSV/VAAPI-only — NVENC addresses GPUs by CUDA
index/UUID, so a multi-entry list warns and uses the first entry instead
of collapsing through the path-presence filter. Sessions now release
their reservation only after ffmpeg has been reaped (shutdown waits on
done first), closing the window where a new start could pick a device
the old process still occupied. Render-device sysfs descriptions move to
gpudetect.go so the allocator file owns only selection/reservation.

* fix(downloads): prepared downloads acquire a GPU through the shared pool

PrepareFile resolves the configured hw_device list to one concrete
device via AcquireHWDevice and holds the reservation until ffmpeg exits
(Run is synchronous, so the deferred release is the process-exit
boundary). Download encodes now participate in the same active-load
accounting as streaming sessions instead of best-effort spreading.

* fix(chapterthumbs): resolve hw_device list per extraction via the shared pool

ExtractFrame acquires one concrete device from AcquireHWDevice for the
hardware attempt (released when the attempt finishes) instead of passing
the raw comma-separated value to ffmpeg as a single device path. The
service stops pre-resolving and caching a device at first use — the raw
configured value flows through and each extraction resolves it.

* fix(transcodenode): fresh starts use this node's configured hw_device

/transcode/start constructed TranscodeOpts with an empty HWDevice, so
fresh sessions auto-detected the first GPU and bypassed the configured
list while reconstructed sessions honored it. Both paths now feed the
node-local config value into StartTranscode's shared resolution.

* feat(admin): node-aware GPU inventory on /admin/system/hw-accel

playback.hw_device is one cluster-wide value consumed by every transcode
node, but the endpoint probed only whichever healthy node had the fewest
jobs — an admin could configure devices that don't exist on the other
nodes. The endpoint now probes every healthy node concurrently and
returns a nodes array (URL, name, resolved accel, devices, or probe
error) alongside the backward-compatible flat fields, and the config doc
states the homogeneous-path contract explicitly.

* feat(admin): GPU picker survives empty detection, warns on node divergence

The picker rows are now the union of detected devices and configured
entries, so configured-but-missing devices stay visible (and
deselectable) when detection returns nothing or an older node omits
render_device_details (plain render_devices paths fall back to a generic
label). Per-node inventories from the hw-accel endpoint drive two
warnings: a banner when responding nodes report different device sets,
and a per-row note listing nodes missing that device. The multi-select
is hidden for NVENC — balancing is QSV/VA-API only — with a notice when
a multi-device value is already stored.

* style: gofmt touched files

* fix(playback): release GPU reservations on process exit

---------

Co-authored-by: rxwatcher <rxwatcher@users.noreply.github.com>
Co-authored-by: Quick <31828688+Quick104@users.noreply.github.com>
2026-08-04 11:33:15 -04:00
2026-07-25 18:37:51 +00:00
2026-05-22 23:26:56 -04:00
2026-05-22 23:26:56 -04:00
2026-05-22 23:26:56 -04:00
2026-05-22 23:26:56 -04:00
2026-07-25 18:37:51 +00:00

Silo

Silo is a self-hosted media streaming server for your movies, shows, music, and books. Point it at your media folders and stream to your devices — at home or away — with direct play, remuxing, and hardware-accelerated transcoding handled automatically.

Join the community on Discord. If Silo is useful to you, consider sponsoring the project — see Supporting Silo.

Highlights

  • Plays your media, your way — direct play when the device supports it, remux or hardware-accelerated transcode (including NVENC) when it doesn't.
  • Web app included — a full-featured web client and admin interface ship with the server.
  • Works with apps you already use — optional Jellyfin/Emby-compatible API supports clients such as VidHub, Findroid, and Infuse.
  • Household profiles — multiple profiles per account, with per-profile watch state and parental controls.
  • Plugin-driven metadata — match and enrich your libraries with providers like TMDB and TVDB, installed as plugins.
  • Fast setup — one docker compose up -d brings up the whole stack; everything else is configured in the admin UI.

The easiest way to run Silo is with Docker Compose. The default stack assumes you do not already have PostgreSQL and Redis available, so it bundles PostgreSQL, Redis, FFmpeg, and the application for a one-command start.

  1. Create a .env file

    cp .env.example .env
    
  2. Set your media path

    Edit .env and set:

    MEDIA_ROOT=/path/to/your/media
    

    MEDIA_ROOT is the one value most users need to change. You can also override SILO_DATA_ROOT if you do not want bind mounts under /opt/silo, and change ports if the defaults conflict with something else on the host.

  3. Start the default integrated stack

    docker compose up -d
    

    This starts PostgreSQL, Redis, and the integrated Silo server. The app is available at http://localhost:8090. Jellyfin-compatible app support is disabled until an administrator enables it in onboarding or admin settings.

    If you already have PostgreSQL and Redis available, omit those bundled service examples from compose and point Silo at your existing DATABASE_URL and REDIS_URL instead.

    Optional NVIDIA/NVENC

    GPU support is kept out of the default compose file so hosts without NVIDIA drivers work unchanged.

    Install the NVIDIA Container Toolkit and use a Docker Compose version with GPU reservation support before enabling this override.

    Use the optional override file when you want NVENC:

    docker compose -f docker-compose.yml -f docker-compose.nvidia.yml up -d
    

    If you want this controlled from .env, set COMPOSE_FILE:

    COMPOSE_FILE=docker-compose.yml:docker-compose.nvidia.yml
    NVIDIA_GPU_COUNT=1
    

    Windows uses ; instead of : between compose files.

    Then docker compose up -d will include the NVIDIA override automatically.

  4. Configure through the admin UI

    Add libraries, users, metadata providers, and playback settings from the web interface.

Bind Mount Layout

The deploy-oriented compose files use host folder mappings rather than Docker-managed volumes.

By default, data is stored under /opt/silo:

  • /opt/silo/postgres
  • /opt/silo/redis
  • /opt/silo/transcode
  • /opt/silo/catalog-seeds

Media is mounted into the container at /mnt/media from the host path you set in MEDIA_ROOT.

Optional Profiles

The main compose file is integrated-first. These profiles exist for operators testing distributed mode or mirroring a split deployment shape. Most single-host installs should stay on the default integrated service, because it already includes proxying and transcoding.

Profile Command Description
default docker compose up -d Integrated server plus bundled PostgreSQL and Redis
proxy docker compose --profile proxy up -d Start a standalone proxy service for distributed-mode testing
transcode docker compose --profile transcode up -d Start a standalone transcode service for distributed-mode testing

You can enable both optional examples together:

docker compose --profile proxy --profile transcode up -d

If you are splitting workers across multiple hosts, use the separate remote worker example instead of trying to stretch the main compose file across machines.

Advanced Remote Node Example

For a dedicated remote transcode worker, use docker-compose.remote-transcode.yml. That file is intended for a separate worker host that connects back to an existing Silo deployment using shared PostgreSQL and Redis.

Deployment Notes

The default compose stack intentionally bundles PostgreSQL and Redis for ease of setup and assumes a fresh install without those services already available. If you already operate PostgreSQL and Redis, omit those examples from compose and point Silo at your existing infrastructure instead. For serious installs, PostgreSQL is better on a separate VM or a managed service so upgrades, tuning, and backups are isolated from the app host. Redis can stay local for many installs, but externalizing it is also reasonable if you already operate shared infrastructure.

Silo is externally stateful by default rather than fully stateless. Durable application state lives in PostgreSQL. Redis only stores coordination and cache-style data. Silo still writes transient transcode output locally under /tmp/silo-transcode. If you switch userdb.backend=sqlite, Silo also becomes locally stateful at /var/lib/silo/userdb.

Migrating an existing Continuum Docker install should be done with the preflight helper and cutover guide in docs/continuum-to-silo-docker-migration.md.

Configuration

Silo requires only a DATABASE_URL when running from source or against external infrastructure. In the default Docker Compose path, the stack wires the database and Redis URLs for you. All other settings — libraries, metadata providers, transcoding, users — are managed through the admin UI after first launch.

Server Modes

Mode Description
integrated Full server: API + frontend + scanner + transcode (default)
api API server only, no local transcoding
proxy Stream proxy node that connects to the shared deployment database and Redis
transcode HLS transcode worker node that connects to the shared deployment database and Redis

PostgreSQL Auto-Tuning

The default Docker Compose stack does not require a checked-in postgresql.conf. It enables Silo's pgtune-style OLTP tuning by default:

POSTGRES_TUNE: auto

When enabled, Silo connects with DATABASE_URL and applies recommendations with ALTER SYSTEM, which writes to PostgreSQL's postgresql.auto.conf inside the database data directory. Reloadable settings are applied immediately with pg_reload_conf(). Settings that PostgreSQL marks as restart-only are written too, and Silo logs the setting names so you can restart PostgreSQL once:

docker compose restart postgres

The default Compose database user has the required PostgreSQL permissions. If you use an external PostgreSQL server, make sure the configured DATABASE_URL user can run ALTER SYSTEM, or set POSTGRES_TUNE=off and manage PostgreSQL yourself.

For POSTGRES_TUNE_MEMORY=auto, Silo uses the first trustworthy memory source: a finite Docker cgroup limit, the read-only /host/proc/meminfo mount supplied by the bundled Compose file, then /proc/meminfo with container safety guards. Auto-detected memory is treated as a PostgreSQL budget, defaulting to 75% of detected RAM so Silo, Redis, plugins, transcodes, and the OS retain headroom. POSTGRES_TUNE_DB_SIZE=auto queries pg_database_size(current_database()) and classifies the workload by comparing the database size to that memory budget.

Optional tuning overrides:

Variable Default Description
POSTGRES_TUNE_PROFILE oltp Tuning profile. Only oltp is currently supported.
POSTGRES_TUNE_MEMORY auto Server/container RAM, such as 8GB or 32GB; explicit values are used as-is.
POSTGRES_TUNE_MEMORY_BUDGET_PERCENT 75 Percent of auto-detected RAM used for PostgreSQL recommendations.
POSTGRES_TUNE_CPUS auto CPU count used for worker recommendations.
POSTGRES_TUNE_STORAGE ssd One of hdd, ssd, san, or nvme.
POSTGRES_TUNE_DB_SIZE auto Use less_ram when the database comfortably fits in RAM, mid_ram, or greater_ram for very large databases.
POSTGRES_TUNE_CONNECTIONS 100 PostgreSQL max_connections; automatically raised if Silo's app pool is configured higher.
POSTGRES_SHM_SIZE 8gb Docker /dev/shm size for the bundled PostgreSQL container.

Advanced operators can still supply their own PostgreSQL configuration or override these env vars. Set POSTGRES_TUNE=off when you do not want Silo to change PostgreSQL server settings. Settings already written with ALTER SYSTEM remain in postgresql.auto.conf; reset those PostgreSQL parameters if you later move fully to a custom postgresql.conf.

Build from Source

If you prefer running Silo without Docker:

  1. Install prerequisites: Go 1.24+, Bun 1.0+, PostgreSQL 18+, and FFmpeg.

  2. Start PostgreSQL and Redis (skip if you already have them running)

    docker compose up -d postgres redis
    

    The main compose file still expects MEDIA_ROOT to be set even if you only want the bundled PostgreSQL and Redis services, so set that in .env first.

  3. Configure the database connection

    cp .env.example .env
    

    Edit .env and set DATABASE_URL to point to your PostgreSQL instance.

  4. Build and run

    make build
    ./silo
    

    The server starts at http://localhost:8080 by default. All other settings are configured through the admin UI.

Reporting Issues

Client implementers can use the Canonical Settings API guide for contract discovery, contextual headers, remote scopes, effective reads, and the admin projection.

If you are reporting a bug, install problem, or performance issue, start with the admin workflow and reproduction steps, not Claude/Codex analysis.

Please include:

  • What you were trying to do
  • Exact steps you took
  • What you expected to happen
  • What actually happened
  • What exact action is slow or broken (save, scan, browse, import, playback, etc.)
  • Whether it happens every time or only sometimes
  • The library, media type, filter, setting, or value involved
  • Version, branch, commit, and deployment details if you know them
  • Screenshots, recordings, or log snippets if relevant

If you used Claude/Codex for debugging, put that under Technical notes at the end. Suspected files, SQL output, stack traces, and root-cause theories can be helpful, but only after the workflow and repro steps are clear.

Use this template:

Goal:
Steps:
Expected:
Actual:
What is slow/broken:
Scope:
Version/branch:
Deployment:
Technical notes:

Contributing & Development

Silo is open source and contributions are welcome. See DEVELOPMENT.md for building from source in a dev workflow, running tests, database migrations, and project layout, and CONTRIBUTING.md for contribution expectations, merge request guidance, and the policy for AI-assisted submissions.

Supporting Silo

Silo is an open-source hobby project, developed in spare time and funded out of pocket. If you'd like to support development, you can sponsor via GitHub Sponsors.

Donations go directly toward the costs of building and running the project:

  • AI development tooling subscriptions (Claude, Codex) used to build and maintain Silo
  • Push notification relay infrastructure
  • Future development costs

Sponsoring is entirely optional — Silo is and will remain free and open source. Bug reports, contributions, and feedback are just as valuable.

License & Trademarks

Silo's source code is licensed under the GNU Affero General Public License v3.0 or later (AGPL-3.0-or-later) — see LICENSE.

The Silo name, logo, and wordmark are trademarks of Silo Media L.L.C. and are not covered by the AGPL. You're free to fork and redistribute the code, but forks and redistributions must not use the Silo brand as their identity and must remove or replace the brand assets. Publishing a Silo-branded app to an app store requires written permission. See TRADEMARK.md for what's permitted — including referential use like "compatible with Silo."

S
Description
Self-hosted media streaming server with a Go backend, React web UI, Docker deployment, transcoding, and Jellyfin-compatible APIs.
Readme
340 MiB
Languages
Go 72.6%
TypeScript 26.3%
PLpgSQL 0.4%
CSS 0.3%
Python 0.2%
Other 0.1%