Tutorial by Examples

Heroku aggregates three categories of logs for your app: App logs - Output from your application. This will include logs generated from within your application, application server and libraries. (Filter: --source app) System logs - Messages about actions taken by the Heroku platform infras...

Each log line is formatted as follows: timestamp source[dyno]: message Timestamp - The date and time recorded at the time the log line was produced by the dyno or component. The timestamp is in the format specified by RFC5424, and includes microsecond precision. Source - All of your app...

To fetch your logs, use the heroku logs command. $ heroku logs The logs command retrieves 100 log lines by default. You can specify the number of log lines to retrieve (up to a maximum of 1,500 lines) by using the --num (or -n) option. $ heroku logs -n 200 Real-time tail Similar to tail -f,...

If you only want to fetch logs with a certain source, a certain dyno, or both, you can use the --source (or -s) and --dyno (or -d) filtering arguments: $ heroku logs --dyno router 2012-02-07T09:43:06.123456+00:00 heroku[router]: at=info method=GET path="/stylesheets/dev-center/library.css&quo...