This method dropped my server to about 3 TPS, you can see the WarmRoast report here. Using Thermos 1.7.10 build 58 and HolographicDisplays v2.2.3.

Just cleaned my server and it had 70k horses and 70k wither skulls, I suspect to be HolographicDisplays:

[04:46:23 INFO]: Removed 140941 entities. ( 6 x Botania.botania:spark ,  4 x Zombie ,  6 x Thaumcraft.Wisp ,  1 x Arrow ,  3 x Thaumcraft.GiantBrainyZombie ,  9 x MinecartChest ,  4 x witchery.hellhound ,  3 x Skeleton ,  5 x Creeper ,  7 x Blaze ,  49 x Item ,  70308 x EntityHorse ,  1 x Spider ,  13 x TConstruct.Bolt ,  47 x Natura.Imp ,  1 x WitherBoss ,  7 x Thaumcraft.AspectOrb ,  17 x witchery.goblin ,  18 x XPOrb ,  9 x Cow ,  1 x Thaumcraft.Golem ,  3 x Forestry.butterflyGE ,  13 x Chicken ,  70307 x WitherSkull ,  3 x Natura.FlameSpider ,  42 x Sheep ,  28 x PigZombie ,  19 x Pig ,  1 x DraconicEvolution.CustomArrow ,  1 x Bat ,  1 x Witch ,  4 x null )

The problem is not that method, the problem is that somehow you have 70k holograms. The method just happens to be the most expensive call for hologram entities.

You probably have a plugin constantly spawning holograms through Holographic Displays.

I dont have any other hologram plugins, or plugins that uses Holograms.

I'm pretty sure you do, I should probably add a command to check what plugin is responsible for that. However, can you check if the count is zero when the server starts and gradually increases?

The could is high even on startup. I deleted the database file and it works now, but eventually increases the holograms anyway.

What was the content of that file? Were there 70k holograms?

Nope. My guess is that, in some loop, holograms were re and re-created. The file was right with the right holograms, after removing it, I guess the "duplicated" holograms weren't created again, not sure...

The commit will not fix the issue, you have to search the cause of the 70k holograms that were spawned.

And how can I do it? I see nothing pointing to things other than the lag caused by the holograms...

You can:

• check if any of your plugins uses holograms (maybe it's not mentioned in the documentation, try opening plugin.yml inside the jar file and search for HolographicDisplays)
• remove other plugins until the issue is resolved, but since you told it only happened once you wouldn't be able to tell if it's resolved or not

I have only a few plugins, and they don't use Holograms at all, and the issue will randomly happen, only once the Holograms (entities) started with the server. Most times they will gradually increase as long as the server is running. An restart fixes the problem, but sometimes we can't restart the server 4+ times per day, players will get mad...

It must be one of those plugins, it's not a common problem (in fact, it's the first time I hear it). Try on a test server with only Holographic Displays, and then gradually add all the other plugins until the issue appears.

I'm closing this issue, since I'm not able to reproduce it. The plugin doesn't randomly create holograms. Also, I've improved the performance of that method by ~8 times.

When did you?

Sorry, I forgot to link the commit: 20acd2f I did a quick benchmark before and after the change.

Hmm, hope it will fix my issue 😃