log4j2.yaml

<?xml version="1.0" encoding="UTF-8"?>
<!-- log4j2.xml - Example log4j configuration file

     Place this file in the same directory as your server.jar, edit
     to taste, and add -Dlog4j.configurationFile=log4j2.xml to your
     server startup flags.

     More log4j example configs can be found at
     <http://logging.apache.org/log4j/2.x/manual/appenders.html>.
-->

<Configuration status="WARN" packages="net.minecraft,com.mojang">
	<Appenders>

		<!-- DEFAULT APPENDERS -->

		<!-- console logging - logs to stdout -->
		<Console name="SysOut" target="SYSTEM_OUT">
			<PatternLayout pattern="[%d{HH:mm:ss}] [%t/%level]: %msg%n" />
		</Console>

		<!-- GUI logging - ignored if you use `java -jar server.jar nogui` -->
		<Queue name="ServerGuiConsole">
			<PatternLayout pattern="[%d{HH:mm:ss} %level]: %msg%n" />
		</Queue>

		<!-- file logging - stuff under the logs/ dir -->
		<RollingRandomAccessFile name="File" fileName="logs/latest.log"
			                     filePattern="logs/%d{yyyy-MM-dd}-%i.log.gz">
			<PatternLayout pattern="[%d{HH:mm:ss}] [%t/%level]: %msg%n" />
			<Policies>
				<TimeBasedTriggeringPolicy />
				<OnStartupTriggeringPolicy />
				<!-- <SizeBasedTriggeringPolicy size="250 MB"/> -->
			</Policies>
			<!-- keep up to 20 files before removing them -->
			<!-- <DefaultRolloverStrategy max="20"/> -->
		</RollingRandomAccessFile>

		<!-- EXAMPLE APPENDERS -->

		<!-- legacy logging - logs to server.log -->
		<File name="LegacyServerLog" fileName="server.log">
			<PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss} [%level] %msg%n" />
		</File>

	</Appenders>
	<Loggers>
		<Root level="error">

			<!-- DEFAULT LOGGERS -->

			<filters>
				<MarkerFilter marker="NETWORK_PACKETS" onMatch="DENY"
				              onMismatch="NEUTRAL" />
			</filters>
			<AppenderRef ref="SysOut"/>
			<AppenderRef ref="File"/>
			<AppenderRef ref="ServerGuiConsole"/>

			<!-- EXAMPLE LOGGERS -->

			<!-- <AppenderRef ref="LegacyServerLog"/> -->
		</Root>
	</Loggers>
</Configuration>

fix chunk border lag from using biome datapacks in minecraft by turning off logging.
add this file to your minecraft dir and add

-Dlog4j.configurationFile=log4j2.xml to your launch variables