I am on version 5.2 (latest one) I checked my configuration and loging was disabled. I have enabled it and now I can see the following…
$ sudo -u mattermost ./bin/mattermost
2018-12-31T05:44:40.828Z info utils/i18n.go:78 Loaded system translations for 'en' from '/home/admin/mattermost/i18n/en.json'
2018-12-31T05:44:40.828Z info app/app.go:143 Server is initializing...
2018-12-31T05:44:40.830Z info sqlstore/supplier.go:207 Pinging SQL master database
2018-12-31T05:44:41.287Z info commands/server.go:82 Current version is 5.6.0 (5.6.2/Sat Dec 22 14:58:39 UTC 2018/3aed6efc6bb5a67fdb8237aac38d46fab3266e8d/2c2d33b22b4c2938938eade4b9914748c1be9d3b)
2018-12-31T05:44:41.287Z info commands/server.go:83 Enterprise Enabled: true
2018-12-31T05:44:41.287Z info commands/server.go:84 Current working directory is /home/admin/mattermost
2018-12-31T05:44:41.287Z info commands/server.go:85 Loaded config file from /home/admin/mattermost/config/config.json
2018-12-31T05:44:41.287Z info filesstore/localstore.go:33 Able to write files to local storage.
2018-12-31T05:44:41.288Z info app/license.go:44 License key from https://mattermost.com required to unlock enterprise features.
2018-12-31T05:44:41.289Z info app/plugin.go:130 Starting up plugins
2018-12-31T05:44:42.116Z info app/server.go:168 Starting Server...
2018-12-31T05:44:42.116Z info app/server.go:228 Server is listening on [::]:8065
2018-12-31T05:44:42.124Z info app/web_hub.go:75 Starting 4 websocket hubs
2018-12-31T05:44:42.131Z info sqlstore/post_store.go:1286 Post.Message supports at most 16383 characters (65535 bytes)
2018-12-31T05:44:42.166Z info jobs/workers.go:68 Starting workers
2018-12-31T05:44:42.166Z info jobs/schedulers.go:72 Starting schedulers.
But it just stays there and nothing happens.
Edit
After enabling DB log as well, i can see lots of queries running after starting scheduler… and then it seems mattermost is working now. will check again later when it stops working