Most Minecraft servers are relatively easy to set up and can be a great way to enjoy multiplayer features with others. Minecraft wouldn't be as popular if it didn't have servers.
The biggest problem with Minecraft servers is the fact that vanilla Minecraft server code can be very poorly optimized. This issue is well-documented by the community. It is mostly due to poor CPU thread usage. The majority of Minecraft server operations are done on a single thread.
This means that Minecraft servers are extremely prone to lag in the current state, especially if there are many players on one server.
There are many plugins admins have the ability to install that optimize server functions and make their server lag less in certain cases.
Clearlag is an old-fashioned, tried-and-true solution to clearing entities and limiting the number of entities on a Minecraft server. Clearlag can be very useful as too many entities in one world can cause FPS lag or TPS loss (serverlag).
Clearlag doesn't just allow you to clear useless entities. It also includes a handy feature that allows you to find laggy chunks. This allows players the ability to teleport directly to these chunks to clear the source of lag manually.
Clearlagg available here
LaggRemover, which has many built-in tools that optimize game processes and help to improve server performance, is another great plugin. It was released in 2015 and has been downloaded over eight million times.
This plugin's “RAM reduction” feature may prove useful for players with a small amount of RAM. This feature reduces the number of chunks that are loaded into memory and thus decreases RAM usage.
Get LaggRemover here
Without knowing what is causing the server to slow down, it can be difficult to optimize it. Spark requires some technical knowledge, but literacy with the plugin can be a big plus.
Spark won't fix all problems, but it will allow players to create detailed profiles of their server and identify which subprocesses are slowing them down.
Get Spark here
Large amounts of lag can be caused by entities in Minecraft, especially mobs. Complex A.I. is responsible for this. This is mainly due to complex A.I. that must be constantly calculated on the server's processor.
Mobs in single-player Minecraft are not a problem because only a handful of mobs can be loaded into the world. This is not true for multiplayer. You can have hundreds or even thousands of mobs loaded at once.
StackMob is a solution to this problem. It stacks close-by mobs with similar traits together. The plugin, for example, will combine all the cows in a single entity. This reduces the CPU load and causes less lag.
Many consider Lagassist the best all-in one lag solution for Minecraft servers. It is a fairly recent plugin that combines some of the most common optimization techniques into a single plugin.
LagAssist, for example, covers the majority of the major functionality of the clearlagg and stackmob plugins. LagAssist is not satisfied with this. They have developed new ways to reduce lag on different types of servers.
These methods can optimize hoppers, break laggy Redstone machines and regulate mob spawning. They even clean laggy chunks of the world automatically.