Launching tests

Once you’ve written a test, you’re ready to run it. Antithesis gives you several ways to launch a test:

• from the web app
• with the API
• through your CI
• with the Snouty CLI

Choose a performance tier

Antithesis lets you choose a performance tier when launching a test run. Higher performance tiers explore system states faster through increased parallelism, and so consume core hours faster. You can track your core hour usage in the web app.

Antithesis provides three performance tiers:

• Standard
• Fast
• Turbo

You can configure the performance tier when you launch a test.

Retroactive logging

Retroactive logging lets you keep verbose logging on during a test with minimal performance overhead. Log lines matching a pattern you provide are suppressed while Antithesis fuzzes your system, and they remain fully recoverable in a multiverse debugging session.

Use one or both of these methods to select logging output to suppress:

• filter_logs_matching suppresses individual log lines whose content matches your pattern.
• filter_source_matching suppresses everything from a particular source, which is useful for silencing a chatty component outright rather than picking lines out of it. This method is only available via API or CLI, not the Test Launcher.

Each launch method below details where to set these. Both take an RE2 pattern:

• Matching is unanchored and case-sensitive. Prefix your pattern with (?i) for case-insensitive matching.
• Lookahead, lookbehind and backreferences are not supported.
• Prefer a simple substring or basic pattern over a full-featured regex.

Matching log lines

If your log lines begin with their level, a good starting point is:

(?i)^\s*(TRACE|DEBUG)\b

This suppresses lines whose first non-whitespace token is TRACE or DEBUG, case-insensitive, and leaves your INFO, WARN and ERROR lines untouched.

Anchoring to the start of the line only works if the level is the first thing on it. Structured loggers typically lead with a timestamp, or emit JSON, so match the level field instead:

(?i)"level":"(trace|debug)"

Either way, check your pattern against a handful of real log lines from your system before launching a long test. Because matching is unanchored, a loose pattern like error suppresses every line that merely contains that word.

Matching sources

A source is the emitter of a log line, usually the name of the process that wrote it. The source field on each line in your logs shows you the names available to match against. Use them exactly as they appear there, especially if you intend to anchor your pattern.

This pattern is matched against the source name rather than against the line, so a match suppresses that source’s entire output:

metrics-agent

Matching is unanchored here too, so that pattern also suppresses a source named metrics-agent-v2. Anchor it with ^ and $ when you want to name a source exactly.

Source matching is set with the antithesis.filter_source_matching parameter through the API, or with --param through the Snouty CLI. It cannot be set in a test launcher dialog.

Launch methods

curl -X POST \
  "https://<tenant>.antithesis.com/api/v1/launch/<launcher_name>" \
  -H "Authorization: Bearer $ANTITHESIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "params": {
      "antithesis.description": "nightly test run",
      "antithesis.duration": "30",
      "antithesis.filter_logs_matching": "(?i)^\\s*(TRACE|DEBUG)\\b"
    }
  }'

snouty launch --webhook basic_test --config ./config --duration 30 \
  --filter-logs-matching '(?i)^\s*(TRACE|DEBUG)\b'

snouty launch --webhook basic_test --config ./config --duration 30 \
  --param 'antithesis.filter_source_matching=^metrics-agent$'

What’s next

Once your test is running, Antithesis will set up your system and explore it for the duration that you configured (minimum 15 minutes). Note that this is minutes of test time — the test run itself will last longer because it also includes set up and build time.

During the test run, you can watch the logs stream in with the logs explorer. Once the run is complete, you can view the triage report summarizing the test results.

See Understand your test results for more ways to explore your test run.