Clear Lag datapack was made with keeping lag out as much in mind. This pack was made to utilize very little resources and keep the lag to minium.
Within this pack you can find the following :
-Automatic Clear Lag For Specific entities.
>This works differently from other clear lag plugins/packs in that it measures the amount of entities and its impact on the server's performance. Whenever a certain threshold is met it clears that specific entity. ie. Threshold For Hostiles : 400, Has been met? = Yes, Thus it clears all hostiles out. These values are modifiable via an command(coming soon - choose which entities are to be cleared and counted)
>Also included is a item counter and a fish counter(for cod) whenever these thresholds are met these mobs are killed.(It is to be noted that fish out of buckets, items that are near you and named mobs are not cleared).
>This DOES not work on a clock So no tick lag.
-Turning off of mob's ai outside a certain radius
>This works only with hostiles and specifically targets them when they're outside a radius of 45 of a gms/gma player ONLY. Mobs with previous NoAi tag will remain so when players enter the needed radius


Installation.
1.Download the datapack(it is highly recommended to run this with hermitcraft's datapacks at xisumavoid.com)
2.Navigate to the datapack folder. Press windows key + r forward by typing in %appdata% and enter. Then navigate to .minecraft and you world)
3.Open the world ingame and run the following function "/function clear_lag:init"
4. Successfully installed!

Admin Commands.
These commands can be manually used to clear lag or modify the threshold values.
>"/function clear_lag:lag/clear_all_lag" - clears all lag
>"/function clear_lag:lag/all_fish" - clears all fish
>"/function clear_lag:lag/kill_cod" - clears all cod
>"/function clear_lag:lag/kill_hostiles" - clears all hostiles
>"/function clear_lag:lag/kill_items" - clears all items

To set the threshold values
"/scoreboard players set AF Threshold <number>"
"/scoreboard players set C Threshold <number>"
"/scoreboard players set AH Threshold <number>"

Additional Info
This pack was made as part of a upcoming hermitcraft revamped pack(discontinued)*
This pack may NOT get updated due to the fact I do not have the time to continue it nor am i getting rewarded for it.
However if this does get popular and people support me, i'll start back updating it and recontinue the hermitcraft revamp pack
Support links will come if it get popular in the form of a discord server

[img=Datapack]blob:www.planetminecraft.com/046def11-67c4-439f-b18b-6f5d0f63c741[/img]

Download Link
http://www.mediafire.com/file/ztrgau22o8vb13c/clear_lag_V.1.0_By_Kirill17.zip/file