Issue: traveling through nether portals causes more lag on a server than simply warping between worlds

The suspicion: Nether portal use ignores cached chunks, and forces some sort of refresh on the cache. Waste of a cache, and CPU cycles. Alternatively, Nether-portal animations are being rendered server-side, causing resource spikes on the server.

 

Testing: For each test, nether portal had already been opened and used, to pre-generate the chunks. Essentials warps were created at each end of the portal, then the server was restarted.

 

1) Fresh restart, wait 2 minutes for everything to fully settle, spawn in overworld, wait 1 more minute (I'm being patient, so as not to screw up the timings), start timings, travel through nether portal, wait for cpu to drop below 50%, paste and stop timings. TPS: 14.1

https://timings.spigotmc.org/?url=qoworuneva

 

2) Same as (1) (restart again), only this time /warp nether was used to travel to the nether world. TPS: 19.9

https://timings.spigotmc.org/?url=wokujutehe

 

3) After restart, portal was used to access nether and return to overworld. After 1 minute, timings was started and portal was used again. TPS: 11.2

https://timings.spigotmc.org/?url=simivigihu

 

4) Same as (3), except /warp nether was used for the second travel. TPS: 19.8

https://timings.spigotmc.org/?url=wicafahida

 

5) Same as (4), except /warp was used for both trips to the nether and back. TPS: 19.8

https://timings.spigotmc.org/?url=cadafijeji

 

6) Same as (4), except warp was used for the initial trips, portal was used for second (timing) trip (to rule out using a portal as clearing the cache). TPS: 10.8

https://timings.spigotmc.org/?url=qosurenawi

 

Not 100% sure what is causing the massive TPS lag, but it is definitely there. The real way to fix this issue would be to track down the cause, but a quick fix could be made by simply calling the portal animation, then warping players between portals after a second or so. Unless, of course, the TPS lag is the portal animation... In which case I'll just disable portals on my server and make people use warp signs.

 

Spigot version 1.11.2

Plugins: Essentials, LANBroadcaster