Can not work well with JDK 9+

[vongosling]

Java 9 introduces overridden methods with covariant return types for the following methods in java.nio.ByteBuffer:

• position​(int newPosition)
• limit​(int newLimit)
• flip​()
• clear​()
• mark​()
• reset​()
• rewind​()

In Java 9 they all now return ByteBuffer, whereas the methods they override return Buffer,
resulting in exceptions like this when executing on Java 8 and lower:
java.lang.NoSuchMethodError: java.nio.ByteBuffer.limit(I)Ljava/nio/ByteBuffer
This is because the generated byte code includes the static return type of the method, which is not found on Java 8 and lower because the overloaded methods with covariant return types don't exist (the issue appears even with source and target 8 or lower in compilation parameters).
The workaroud solution is to cast ByteBuffer instances to Buffer before calling the method. So, If we want to support JDK 11, we need to polish here and keep be compatible.

[Cczzzz]

this is my runbroker.sh .
It can run normally on jdk11 with zgc

#!/bin/sh

# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

#===========================================================================================
# Java Environment Setting
#===========================================================================================
error_exit ()
{
    echo "ERROR: $1 !!"
    exit 1
}

[ ! -e "$JAVA_HOME/bin/java" ] && JAVA_HOME=$HOME/jdk/java
[ ! -e "$JAVA_HOME/bin/java" ] && JAVA_HOME=/usr/java
[ ! -e "$JAVA_HOME/bin/java" ] && error_exit "Please set the JAVA_HOME variable in your environment, We need java(x64)!"

export JAVA_HOME
export JAVA="$JAVA_HOME/bin/java"
export BASE_DIR=$(dirname $0)/..
export CLASSPATH=.:${BASE_DIR}/conf:${CLASSPATH}:${BASE_DIR}/lib/*

#===========================================================================================
# JVM Configuration
#===========================================================================================
# The RAMDisk initializing size in MB on Darwin OS for gc-log
DIR_SIZE_IN_MB=600

choose_gc_log_directory()
{
    case "`uname`" in
        Darwin)
            if [ ! -d "/Volumes/RAMDisk" ]; then
                # create ram disk on Darwin systems as gc-log directory
                DEV=`hdiutil attach -nomount ram://$((2 * 1024 * DIR_SIZE_IN_MB))` > /dev/null
                diskutil eraseVolume HFS+ RAMDisk ${DEV} > /dev/null
                echo "Create RAMDisk /Volumes/RAMDisk for gc logging on Darwin OS."
            fi
            GC_LOG_DIR="/Volumes/RAMDisk"
        ;;
        *)
            # check if /dev/shm exists on other systems
            if [ -d "/dev/shm" ]; then
                GC_LOG_DIR="/dev/shm"
            else
                GC_LOG_DIR=${BASE_DIR}
            fi
        ;;
    esac
}

choose_gc_log_directory

JAVA_OPT="${JAVA_OPT} -server -Xms10g -Xmx10g"
# JAVA_OPT="${JAVA_OPT} -XX:+UseG1GC -XX:G1HeapRegionSize=16m -XX:G1ReservePercent=25 -XX:InitiatingHeapOccupancyPercent=30 -XX:SoftRefLRUPolicyMSPerMB=0"
# JAVA_OPT="${JAVA_OPT} -verbose:gc -Xloggc:${GC_LOG_DIR}/rmq_broker_gc_%p_%t.log -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCApplicationStoppedTime -XX:+PrintAdaptiveSizePolicy"
# JAVA_OPT="${JAVA_OPT} -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=5 -XX:GCLogFileSize=30m"
JAVA_OPT="${JAVA_OPT} -XX:ReservedCodeCacheSize=256m -XX:InitialCodeCacheSize=256m "
JAVA_OPT="${JAVA_OPT} -XX:+UnlockExperimentalVMOptions -XX:+UseZGC "
JAVA_OPT="${JAVA_OPT} -XX:ConcGCThreads=2 -XX:ParallelGCThreads=6 "
JAVA_OPT="${JAVA_OPT} -Xlog:safepoint,classhisto*=trace,age*,gc*=info:${GC_LOG_DIR}/rmq_broker_gc_%p_%t.log:time,tid,tags:filecount=5,filesize=50m "
JAVA_OPT="${JAVA_OPT} --add-exports=java.base/jdk.internal.ref=ALL-UNNAMED"
JAVA_OPT="${JAVA_OPT} -XX:-OmitStackTraceInFastThrow"
JAVA_OPT="${JAVA_OPT} -XX:+AlwaysPreTouch"
JAVA_OPT="${JAVA_OPT} -XX:MaxDirectMemorySize=15g"
JAVA_OPT="${JAVA_OPT} -XX:-UseLargePages -XX:-UseBiasedLocking"
# JAVA_OPT="${JAVA_OPT} -Djava.ext.dirs=${JAVA_HOME}/jre/lib/ext:${BASE_DIR}/lib:${JAVA_HOME}/lib/ext"
#JAVA_OPT="${JAVA_OPT} -Xdebug -Xrunjdwp:transport=dt_socket,address=9555,server=y,suspend=n"
JAVA_OPT="${JAVA_OPT} ${JAVA_OPT_EXT}"
JAVA_OPT="${JAVA_OPT} -cp ${CLASSPATH}"

numactl --interleave=all pwd > /dev/null 2>&1
if [ $? -eq 0 ]
then
	if [ -z "$RMQ_NUMA_NODE" ] ; then
		numactl --interleave=all $JAVA ${JAVA_OPT} $@
	else
		numactl --cpunodebind=$RMQ_NUMA_NODE --membind=$RMQ_NUMA_NODE $JAVA ${JAVA_OPT} $@
	fi
else
	$JAVA ${JAVA_OPT} $@
fi

[Cczzzz]

error_exit ()
{
    echo "ERROR: $1 !!"
    exit 1
}

[ ! -e "$JAVA_HOME/bin/java" ] && JAVA_HOME=$HOME/jdk/java
[ ! -e "$JAVA_HOME/bin/java" ] && JAVA_HOME=/usr/java
[ ! -e "$JAVA_HOME/bin/java" ] && error_exit "Please set the JAVA_HOME variable in your environment, We need java(x64)!"

export JAVA_HOME
export JAVA="$JAVA_HOME/bin/java"
export BASE_DIR=$(dirname $0)/..
export CLASSPATH=.:${BASE_DIR}/conf:${CLASSPATH}:${BASE_DIR}/lib/*

#===========================================================================================
# JVM Configuration
#===========================================================================================
# The RAMDisk initializing size in MB on Darwin OS for gc-log
DIR_SIZE_IN_MB=600

choose_gc_log_directory()
{
    case "`uname`" in
        Darwin)
            if [ ! -d "/Volumes/RAMDisk" ]; then
                # create ram disk on Darwin systems as gc-log directory
                DEV=`hdiutil attach -nomount ram://$((2 * 1024 * DIR_SIZE_IN_MB))` > /dev/null
                diskutil eraseVolume HFS+ RAMDisk ${DEV} > /dev/null
                echo "Create RAMDisk /Volumes/RAMDisk for gc logging on Darwin OS."
            fi
            GC_LOG_DIR="/Volumes/RAMDisk"
        ;;
        *)
            # check if /dev/shm exists on other systems
            if [ -d "/dev/shm" ]; then
                GC_LOG_DIR="/dev/shm"
            else
                GC_LOG_DIR=${BASE_DIR}
            fi
        ;;
    esac
}

choose_gc_log_directory

JAVA_OPT="${JAVA_OPT} -server -Xms8g -Xmx8g"
# JAVA_OPT="${JAVA_OPT} -XX:+UseG1GC -XX:G1HeapRegionSize=16m -XX:G1ReservePercent=25 -XX:InitiatingHeapOccupancyPercent=30 -XX:SoftRefLRUPolicyMSPerMB=0"
# JAVA_OPT="${JAVA_OPT} -verbose:gc -Xloggc:${GC_LOG_DIR}/rmq_broker_gc_%p_%t.log -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCApplicationStoppedTime -XX:+PrintAdaptiveSizePolicy"
# JAVA_OPT="${JAVA_OPT} -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=5 -XX:GCLogFileSize=30m"
JAVA_OPT="${JAVA_OPT} -XX:ReservedCodeCacheSize=256m -XX:InitialCodeCacheSize=256m "
JAVA_OPT="${JAVA_OPT} -XX:+UnlockExperimentalVMOptions -XX:+UseZGC "
JAVA_OPT="${JAVA_OPT} -XX:ConcGCThreads=2 -XX:ParallelGCThreads=6 "
JAVA_OPT="${JAVA_OPT} -Xlog:safepoint,classhisto*=trace,age*,gc*=info:${GC_LOG_DIR}/rmq_broker_gc_%p_%t.log:time,tid,tags:filecount=5,filesize=50m "

JAVA_OPT="${JAVA_OPT} --add-opens java.base/java.nio=ALL-UNNAMED"
JAVA_OPT="${JAVA_OPT} --add-opens java.base/java.lang=ALL-UNNAMED"
JAVA_OPT="${JAVA_OPT} --add-opens java.base/jdk.internal.ref=ALL-UNNAMED"
JAVA_OPT="${JAVA_OPT} --add-opens java.base/sun.nio.ch=ALL-UNNAMED"

#JAVA_OPT="${JAVA_OPT} -Ddledger.disk.ratio.check=0.75"
#JAVA_OPT="${JAVA_OPT} -Ddledger.disk.ratio.clean=0.80"

JAVA_OPT="${JAVA_OPT} -XX:-OmitStackTraceInFastThrow"
JAVA_OPT="${JAVA_OPT} -XX:+AlwaysPreTouch"
JAVA_OPT="${JAVA_OPT} -XX:MaxDirectMemorySize=15g"
JAVA_OPT="${JAVA_OPT} -XX:-UseLargePages"
# JAVA_OPT="${JAVA_OPT} -Djava.ext.dirs=${JAVA_HOME}/jre/lib/ext:${BASE_DIR}/lib:${JAVA_HOME}/lib/ext"
#JAVA_OPT="${JAVA_OPT} -Xdebug -Xrunjdwp:transport=dt_socket,address=9555,server=y,suspend=n"
JAVA_OPT="${JAVA_OPT} ${JAVA_OPT_EXT}"
JAVA_OPT="${JAVA_OPT} -cp ${CLASSPATH}"

numactl --interleave=all pwd > /dev/null 2>&1
if [ $? -eq 0 ]
then
	if [ -z "$RMQ_NUMA_NODE" ] ; then
		numactl --interleave=all $JAVA ${JAVA_OPT} $@
	else
		numactl --cpunodebind=$RMQ_NUMA_NODE --membind=$RMQ_NUMA_NODE $JAVA ${JAVA_OPT} $@
	fi
else
	$JAVA ${JAVA_OPT} $@
fi

use this. you can run on jdk-17 zgc .

[Cczzzz]

Notice：
If you find in the gc log ，
Allocation Stall (xxxxx) 32.729ms similar.

you should increase them.
-XX:ConcGCThreads=2 -XX:ParallelGCThreads=6