RESTBase

RESTBase is an API proxy serving the REST API at /api/rest_v1/. It uses Cassandra as a storage backend.

It is currently running on hosts with the profile::restbase class.

Deployment and config changes

RESTBase is deployed by Scap.

What to check after a deploy

Deploys to do not always go according to plan, and regressions are not always obvious. Here is a list of things you should check after each deploy:

• Does the API documentation still load? Consider exercising some of the endpoints from the UI (perhaps by requesting an html render).
• Check error logs in logstash.
• Have a look at the metrics in Grafana. Have latencies increased, or error rates jumped? Is memory utilization consistent with expectations? What about storage (op rates, exceptions, etc)?
• Consider making an edit to a page using Visual Editor.
• Take a look at some recent Visual Editor-performed changes (French Wikipedia works great for this, as they use VE by default). Do the diffs looks reasonable?
• Keep a close eye on #wikimedia-operations, if someone spots a problem, they're likely to raise the issue there.

Other considerations

Be sure to log all actions ahead of time in #wikimedia-operations. Don't be shy about including details.

Debugging

To temporarily switch to local logging for debugging, you can change the config.yaml log stanza like this:

logging:
  name: restbase
  streams:
    # level can be trace, debug, info, warn, error
    - level: info 
      path: /tmp/debug.log

Alternatively, you can log to stdout by commenting out the streams sub-object. This is useful for debugging startup failures like this:

cd /srv/deployment/restbase/deploy/
sudo -u restbase node restbase/server.js -c /etc/restbase/config.yaml -n 0

The -n 0 parameter avoids forking off any workers, which reduces log noise. Instead, a single worker is started up right in the master process.

Analytics and metrics

• RESTBase grafana dashboard
• API summary dashboard

Hive query for action API & rest API traffic:

use wmf;

SELECT
  SUM(IF (uri_path LIKE '/api/rest_v1/%', 1, 0)) as count_rest,
  SUM(IF (uri_path LIKE '/w/api.php%', 1, 0)) as count_action
FROM wmf.webrequest
WHERE webrequest_source = 'text'
  AND year = 2017
  AND month = 9
  AND (uri_path LIKE '/api/rest_v1/%' OR uri_path LIKE '/w/api.php%');