Logs and monitoring

Silo is in active development before 1.0. These guides are updated frequently.

Use Admin > Logs for searchable server logs. Use the container logs when Silo fails before the web app is available.

View logs

From the directory that holds your Compose file:

docker compose logs --tail 100 --timestamps silo

Add --follow to watch new lines while you reproduce a problem. Press Ctrl+C to stop watching; Silo keeps running.

In Admin > Logs, search around the time of the failure by message, component, request ID, or playback session ID. Early database and migration messages can appear only in the container logs, because Silo writes them before the admin log starts collecting.

Log settings

In Admin > Settings > General, under Logging:

Setting	Effect	Takes effect
Log level	Lowest level written to the container log and to OpenTelemetry export	Immediately
Quiet log prefixes (under Advanced)	Drops lines that start with any of these words	Immediately

Set Log level to Debug only while you collect a short sample, then set it back.

Admin > Logs has its own threshold and keeps Info and above by default, so Debug doesn’t add lines there. Two stored settings have no control in the web app. You can change them through the admin API, and both need a restart:

• opslog.capture_level: the lowest level kept in Admin > Logs (debug, info, warn, or error)
• server.log_format: text or json in the container log

Redaction

Silo masks structured fields with secret-like names, such as passwords, tokens, authorization headers, and cookies. It cannot recognize every secret inside free-form message text.

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Retention

Set how long Admin > Logs keeps entries in Admin > Settings > Storage & Database, under Logs: Delete log entries older than, Maximum log entries, and Maximum log size.

Docker keeps container logs separately. For Docker’s json-file driver, a Compose override can cap them:

services:
  silo:
    logging:
      driver: json-file
      options:
        max-size: "50m"
        max-file: "5"

Add this to your existing override if you have one. Applying it recreates the container, which interrupts playback.

Metrics

Prometheus metrics are off on the main server until you set SILO_METRICS_LISTEN to a listen address, for example SILO_METRICS_LISTEN=127.0.0.1:9091. The /metrics route has no authentication, so keep it on a private network and don’t publish or proxy it. Inside Docker, 127.0.0.1 is the container itself, so your collector needs a private route to that address.

Proxy and transcode nodes serve /metrics on their own port without authentication. Keep those ports private too.

For health and readiness checks, see Check server health.

OpenTelemetry export

To send logs to an existing OpenTelemetry collector, add its endpoint and protocol to .env, then recreate the container with docker compose up -d:

OTEL_EXPORTER_OTLP_ENDPOINT=https://collector.example.com
OTEL_EXPORTER_OTLP_PROTOCOL=http/protobuf

Replace the example with your collector’s address and configure the authentication and certificates it needs. Setting OTEL_EXPORTER_OTLP_ENDPOINT turns export on. Setting only the per-signal endpoint variables does not; set SILO_OTEL_ENABLED=true in that case. Inside Docker, localhost does not reach a collector in another container, so use a hostname the Silo container can reach.

Export is best effort. If the collector fails, the container log and Admin > Logs keep working, but buffered export data can be lost. Keep history you need at the collector.