takidelfin

yup, it affects 19w04a too :/ 
It makes the game unplayable for me. I always thought that "vanilla" servers are a lot lighter than Bukkit/Spigot...
4 GB RAM Allocated, Intel i7 4790k, server runs on SSD (520MB/s rw)

This issue still occurs on 19w02

I can confirm that this issue still occurs in 18w50a:

Ubuntu 18.04
Can confirm it for 18w50a on an internal or standalone server.

Standalone server:

Pre-load❓ time, before anything will show up in a console, takes ~ 30 seconds. It takes so long to start a server (usually 58 seconds, the highest time I got was 145 seconds). After some time, server crashes after exceeding 1-minute tick delay (Watchdog)