内存分配策略

# 0， 表示内核将检查是否有足够的可用内存供应用进程使用；如果有足够的可用内存，内存申请允许；否则，内存申请失败，并把错误返回给应用进程。
# 1， 表示内核允许分配所有的物理内存，而不管当前的内存状态如何。
# 2， 表示内核允许分配超过所有物理内存和交换空间总和的内存
# vm.overcommit_memory = 1

net.bridge.bridge-nf-call-ip6tables=1
net.bridge.bridge-nf-call-iptables=1
net.ipv4.ip_forward=1
net.ipv4.conf.all.forwarding=1
net.ipv4.neigh.default.gc_thresh1=4096
net.ipv4.neigh.default.gc_thresh2=6144
net.ipv4.neigh.default.gc_thresh3=8192
net.ipv4.neigh.default.gc_interval=60
# 决定检查过期多久邻居条目
net.ipv4.neigh.default.gc_stale_time=120

# 参考 https://github.com/prometheus/node_exporter#disabled-by-default
kernel.perf_event_paranoid=-1

#sysctls for k8s node config
net.ipv4.tcp_slow_start_after_idle=0
net.core.rmem_max=16777216
fs.inotify.max_user_watches=524288
kernel.softlockup_all_cpu_backtrace=1

kernel.softlockup_panic=0

kernel.watchdog_thresh=30
# 设定最大打开文件句柄数为 2097152
fs.file-max=2097152
fs.inotify.max_user_instances=8192
fs.inotify.max_queued_events=16384
vm.max_map_count=262144
net.core.netdev_max_backlog=16384
net.ipv4.tcp_wmem=4096 12582912 16777216
net.core.wmem_max=16777216
net.core.somaxconn=32768
net.ipv4.ip_forward=1
net.ipv4.tcp_max_syn_backlog=8096
net.ipv4.tcp_rmem=4096 12582912 16777216

# 关闭 ipv6
net.ipv6.conf.all.disable_ipv6=1
net.ipv6.conf.default.disable_ipv6=1
net.ipv6.conf.lo.disable_ipv6=1

vm.swappiness=0

# 可以控制core文件的文件名中是否添加pid作为扩展。
kernel.core_uses_pid=1

# # 处理无源路由的包
net.ipv4.conf.default.accept_source_route=0
net.ipv4.conf.all.accept_source_route=0

# Promote secondary addresses when the primary address is removed
net.ipv4.conf.default.promote_secondaries=1
net.ipv4.conf.all.promote_secondaries=1

# Enable hard and soft link protection
fs.protected_hardlinks=1
fs.protected_symlinks=1

# 源路由验证
# see details in https://help.aliyun.com/knowledge_detail/39428.html
net.ipv4.conf.all.rp_filter=0
net.ipv4.conf.default.rp_filter=0
net.ipv4.conf.default.arp_announce = 2
net.ipv4.conf.lo.arp_announce=2
net.ipv4.conf.all.arp_announce=2

# see details in https://help.aliyun.com/knowledge_detail/41334.html
net.ipv4.tcp_max_tw_buckets=5000
net.ipv4.tcp_syncookies=1
net.ipv4.tcp_fin_timeout=30
net.ipv4.tcp_synack_retries=2
kernel.sysrq=1