Resources (CPU & memory limits)

On your own server, a container can use the whole machine unless you say otherwise. That's usually what you want: it's your hardware. Resources is where you set a ceiling, so that one project can't take all the memory and push the others out, or so a small box doesn't fall over during a heavy job.

Resources decide how much a project may use. To decide where it runs (dedicated cores, CPU priority, a memory guarantee), see Dedicated CPU cores & reservations.

Where it is

Open the project and choose Resources in the project menu. The Machine Power card is at the top, with CPU & memory placement and Replicas under it. The same Machine Power card is also on the Configuration tab of a single app and on the Apps & Services tab of a project with services.

The card's header shows the target machine's size, for example Machine: 8 vCPU · 16 GB, read from its Docker daemon.

Set a limit

What the limits do

• CPU is a share of processor time. A container limited to 0.5 vCPU gets at most half a core, even on an idle server; it slows down rather than failing.
• Memory is a hard cap. A container that tries to use more is stopped by the kernel (an "out of memory" kill) and restarted according to its restart policy. If an app keeps restarting after you set a memory cap, raise it.
• The value is checked against the machine: Memory limit 8192 MB exceeds the machine's 2048 MB. A non-zero value must be at least 0.25 cores and 128 MB. If Synq can't reach the machine to read its size, it accepts the value without a ceiling.
• The limits are per container. An app running replicas gives each replica the full limit, so three replicas of a 1 GB app can use 3 GB together.

Per-service limits

In a project with services, the project value applies to each container on its own (it's a cap per container, not a budget shared between them).

A service can override it. Synq reads a Compose file's own limits in either spelling and applies them over the project value field by field, so a service that sets only memory keeps the project's CPU value:

services:
  api:
    image: my/api
    mem_limit: 4g          # short form
    cpus: 2
  worker:
    image: my/worker
    deploy:                # long form, also read
      resources:
        limits:
          memory: 8G
          cpus: "1.5"

The same override is available in synq.json under services[].resources.

Build limits

Builds are uncapped too. On a small server, an unbounded production build can take the whole machine for a few minutes; to prevent that, cap the build separately through the API (below). There is no build setting in the panel.

From the API

# Read the current values, the machine's capacity, and whether a limit is required
curl -H "Authorization: Bearer $SYNQ_TOKEN" \
  "$SYNQ_URL/api/projects/$PROJECT_ID/resources"

# Use a tier for the app
curl -X PATCH -H "Authorization: Bearer $SYNQ_TOKEN" -H "Content-Type: application/json" \
  -d '{"production":{"tier":"medium"}}' \
  "$SYNQ_URL/api/projects/$PROJECT_ID/resources"

# Custom values for the app, and a cap for its builds
curl -X PATCH -H "Authorization: Bearer $SYNQ_TOKEN" -H "Content-Type: application/json" \
  -d '{"production":{"cpuCores":1.5,"memoryMb":3072},"build":{"cpuCores":2,"memoryMb":2048}}' \
  "$SYNQ_URL/api/projects/$PROJECT_ID/resources"

# Remove the caps again
curl -X PATCH -H "Authorization: Bearer $SYNQ_TOKEN" -H "Content-Type: application/json" \
  -d '{"production":{"tier":"unlimited"}}' \
  "$SYNQ_URL/api/projects/$PROJECT_ID/resources"

SYNQ_URL is your panel address (for example https://app.example.com). Tiers are unlimited, micro, low, medium, high and xlarge; explicit numbers use cpuCores, memoryMb and diskMb (disk is not enforced on your own servers). Every field is optional.

Sleep mode

Projects also carry a sleep mode setting, auto_sleep (the default) or always_on, which you can set with the CLI or the API:

synq project sleep-mode <project-id> always_on

On your own servers this setting is stored but has no effect: containers run continuously and are never put to sleep when idle, whichever value you choose. There is no idle-stop or wake-on-request on a Synq server. To stop an app, stop it (or disable the project); to take it offline for visitors while it keeps running, use maintenance mode.

Troubleshooting

Related guides