Any cause for concerns here?

I know Kong has thrown log messages in the past starting up that are not really to be concerned with, a new one I am seeing now lately:

2018/04/24 14:31:02 [notice] 14#0: using the "epoll" event method
2018/04/24 14:31:02 [notice] 14#0: openresty/1.13.6.1
2018/04/24 14:31:02 [notice] 14#0: built by gcc 6.3.0 (Alpine 6.3.0) 
2018/04/24 14:31:02 [notice] 14#0: OS: Linux 3.10.0-693.11.1.el7.x86_64
2018/04/24 14:31:02 [notice] 14#0: getrlimit(RLIMIT_NOFILE): 1048576:1048576
2018/04/24 14:31:02 [notice] 14#0: start worker processes
2018/04/24 14:31:02 [notice] 14#0: start worker process 52
2018/04/24 14:31:02 [notice] 14#0: start worker process 53
2018/04/24 14:31:02 [notice] 14#0: start worker process 54
2018/04/24 14:31:02 [notice] 14#0: start worker process 55
2018/04/24 14:31:02 [notice] 14#0: start worker process 56
2018/04/24 14:31:02 [notice] 14#0: start worker process 57
2018/04/24 14:31:02 [notice] 14#0: start worker process 58
2018/04/24 14:31:02 [notice] 14#0: start worker process 59
2018/04/24 14:31:09 [error] 53#0: *11 [lua] events.lua:103: errlog(): worker-events: dropping event; waiting for event data timed out, id: 3, context: ngx.timer
2018/04/24 14:31:09 [error] 53#0: *11 [lua] events.lua:103: errlog(): worker-events: dropping event; waiting for event data timed out, id: 4, context: ngx.timer
2018/04/24 14:31:09 [error] 53#0: *11 [lua] events.lua:103: errlog(): worker-events: dropping event; waiting for event data timed out, id: 5, context: ngx.timer
2018/04/24 14:31:09 [error] 53#0: *11 [lua] events.lua:103: errlog(): worker-events: dropping event; waiting for event data timed out, id: 6, context: ngx.timer
2018/04/24 14:31:09 [error] 53#0: *11 [lua] events.lua:103: errlog(): worker-events: dropping event; waiting for event data timed out, id: 7, context: ngx.timer
2018/04/24 14:31:09 [error] 53#0: *11 [lua] events.lua:103: errlog(): worker-events: dropping event; waiting for event data timed out, id: 8, context: ngx.timer
2018/04/24 14:31:09 [error] 52#0: *13 [lua] events.lua:103: errlog(): worker-events: dropping event; waiting for event data timed out, id: 2, context: ngx.timer
2018/04/24 14:31:09 [error] 52#0: *13 [lua] events.lua:103: errlog(): worker-events: dropping event; waiting for event data timed out, id: 3, context: ngx.timer
2018/04/24 14:31:09 [error] 52#0: *13 [lua] events.lua:103: errlog(): worker-events: dropping event; waiting for event data timed out, id: 4, context: ngx.timer
2018/04/24 14:31:09 [error] 52#0: *13 [lua] events.lua:103: errlog(): worker-events: dropping event; waiting for event data timed out, id: 5, context: ngx.timer
2018/04/24 14:31:09 [error] 52#0: *13 [lua] events.lua:103: errlog(): worker-events: dropping event; waiting for event data timed out, id: 6, context: ngx.timer
2018/04/24 14:31:09 [error] 52#0: *13 [lua] events.lua:103: errlog(): worker-events: dropping event; waiting for event data timed out, id: 7, context: ngx.timer
2018/04/24 14:31:09 [error] 52#0: *13 [lua] events.lua:103: errlog(): worker-events: dropping event; waiting for event data timed out, id: 8, context: ngx.timer

Just more startup gibberish to not worry about?

We have seen this once before. It is caused by the initialisation of a worker taking too long. It is harmless in itself, but obviously should not happen.

What database are you using?

also, can you please create a github issue for this? please include relevant info; complete log, database, number of workers (number of cpu cores, or the actual number if configured differently) and any other relevant info.

Sure, I will make an issue. We are using Cassandra. I will start kong up in debug mode to give you some robust logs in a Github issue as requested here shortly!

As promised: https://github.com/Kong/kong/issues/3417