-
設定swap（預設為60, 當系統使用到超過40% memory, 就會嘗試使用swap）
sysctl -w vm.swappiness=0 # from 60 -> 0 -
Huge Page (especially THP)
for mongodb: https://jira.mongodb.org/browse/DOCS-2131
echo never > /sys/kernel/mm/transparent_hugepage/enabled
-
File System flush issues
# vm.dirty_ratio = 80 # from 40 # vm.dirty_background_ratio = 5 # from 10 # vm.dirty_expire_centisecs = 12000 # from 3000 -
For Mongodb Disk Mounting
modify
/etc/fstab/dev/xvdf /mongodb_data ext4 defaults,auto,noatime,noexec 0 0 /dev/xvdg /journal ext4 defaults,auto,noatime,noexec 0 0 /dev/xvdh /log ext4 defaults,auto,noatime,noexec 0 0 -
設定readahead
sudo blockdev --setra 32 /dev/xvdf可以利用
sudo blockdev --report觀看是否設定成功每次開完機自動設定
echo 'ACTION=="add", KERNEL=="xvdf", ATTR{bdi/read_ahead_kb}="16"' | sudo tee -a /etc/udev/rules.d/85-ebs.rulesref: http://docs.mongodb.org/ecosystem/platforms/amazon-ec2/
-
ulimit
$ sudo nano /etc/security/limits.conf * soft nofile 64000 * hard nofile 64000 * soft nproc 32000 * hard nproc 32000 $ sudo nano /etc/security/limits.d/90-nproc.conf * soft nproc 32000 * hard nproc 32000
sudo vim /etc/sysctl.conf
vm.swappiness = 0 # from 60
vm.dirty_ratio = 80 # from 40
vm.dirty_background_ratio = 5 # from 10
vm.dirty_expire_centisecs = 12000 # from 3000
- 設定swap（預設為60, 當系統使用到超過40% memory, 就會嘗試使用swap）
vm.dirty_ratio是如果 dirty page 真的超過多少就強制回寫- 這個參數主要是降低 Linux 寫檔案(dirty page)的 buffer 大小，如果是寫入的量很大的系統建議降低此值
- Ref: http://parseflo.at/post/linux-tuning-for-write-heavy-system/
sudo sysctl -p /etc/sysctl.conf # reload settings
Huge Page (especially THP) for mongodb: https://jira.mongodb.org/browse/DOCS-2131
echo never > /sys/kernel/mm/transparent_hugepage/enabled
change xvdf
echo noop | sudo tee /sys/block/xvdf/queue/scheduler
/sys/block/*/queue/rq_affinity 2
/sys/block/*/queue/scheduler noop
/sys/block/*/queue/nr_requests 256
/sys/block/*/queue/read_ahead_kb 256
mdadm –chunk=64 ...
modify /etc/fstab (using discard to activate TRIM function)
/dev/xvdf /mongodb_data ext4 defaults,auto,discard,noatime,noexec 0 0
/dev/xvdg /journal ext4 defaults,auto,discard,noatime,noexec 0 0
/dev/xvdh /log ext4 defaults,auto,discard,noatime,noexec 0 0
sudo vim /etc/security/limits.conf
* soft nofile 64000
* hard nofile 64000
* soft nproc 32000
* hard nproc 32000
sudo vim /etc/sysctl.conf
net.core.somaxconn = 1000
net.core.netdev_max_backlog = 5000
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_wmem = 4096 12582912 16777216
net.ipv4.tcp_rmem = 4096 12582912 16777216
net.ipv4.tcp_max_syn_backlog = 8096
net.ipv4.tcp_slow_start_after_idle = 0
net.ipv4.tcp_tw_reuse = 1
net.ipv4.ip_local_port_range = 10240 65535
net.ipv4.tcp_abort_on_overflow = 1 # maybe