登陸mongodb 數據庫:顯示報警信息如下:
2018-09-12T05:41:06.390+0000 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.
2018-09-12T05:41:06.390+0000 I CONTROL [initandlisten] ** We suggest setting it to 'never'
原因:
就是允許hugepage可以動態分配,而不是系統啓動時預先分配,對內存消耗很大的服務都不喜歡它,坑人無數。
這個配置會在多個服務上都是坑 :hdfs 、elasticsearch ,mongodb ,oracle ,推薦默認系統初始化就關掉。
關閉方法:
centos上的關閉方法是
echo never > /sys/kernel/mm/transparent_hugepage/enabled
ubuntu:
echo never > /sys/kernel/mm/transparent_hugepage/enabled
echo never> /sys/kernel/mm/transparent_hugepage/defrag
永久關閉
寫入文件 :/etc/rc.local
if test -f /sys/kernel/mm/transparent_hugepage/enabled; then
echo never > /sys/kernel/mm/transparent_hugepage/enabled
fi
if test -f /sys/kernel/mm/transparent_hugepage/defrag; then
echo never > /sys/kernel/mm/transparent_hugepage/defrag
fi
或者
1: Create the init.d script.
Create the following file at /etc/init.d/disable-transparent-hugepages:
#!/bin/bash
### BEGIN INIT INFO
# Provides: disable-transparent-hugepages
# Required-Start: $local_fs
# Required-Stop:
# X-Start-Before: mongod mongodb-mms-automation-agent
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: Disable Linux transparent huge pages
# Description: Disable Linux transparent huge pages, to improve
# database performance.
### END INIT INFO
case $1 in
start)
if [ -d /sys/kernel/mm/transparent_hugepage ]; then
thp_path=/sys/kernel/mm/transparent_hugepage
elif [ -d /sys/kernel/mm/redhat_transparent_hugepage ]; then
thp_path=/sys/kernel/mm/redhat_transparent_hugepage
else
return 0
fi
echo 'never' > ${thp_path}/enabled
echo 'never' > ${thp_path}/defrag
re='^[0-1]+$'
if [[ $(cat ${thp_path}/khugepaged/defrag) =~ $re ]]
then
# RHEL 7
echo 0 > ${thp_path}/khugepaged/defrag
else
# RHEL 6
echo 'no' > ${thp_path}/khugepaged/defrag
fi
unset re
unset thp_path
;;
esac
2
Make it executable.
Run the following command to ensure that the init script can be used:
sudo chmod 755 /etc/init.d/disable-transparent-hugepages
參考信息:
http://www.mongoing.com/docs/tutorial/transparent-huge-pages.html
https://blog.csdn.net/csfreebird/article/details/49307935