## added by samiux for performance and security

# performance tuning
kernel.sem = 250 32000 100 128
kernel.shmall = 2097152
kernel.shmmax = 2147483648
kernel.shmmni = 4096
# If you have more than 512MB RAM, use this setting unless comment it out
fs.file-max = 262140
# If you have 512MB RAM or less, uncomment this setting; otherwise, comment it out
#fs.file-max = 65535
vm.swappiness = 1
vm.vfs_cache_pressure = 50
vm.min_free_kbytes = 65536

net.core.rmem_default = 33554432
net.core.rmem_max = 33554432
net.core.wmem_default = 33554432
net.core.wmem_max = 33554432
net.ipv4.tcp_rmem = 10240 87380 33554432
net.ipv4.tcp_wmem = 10240 87380 33554432
net.ipv4.tcp_no_metrics_save = 1
net.ipv4.tcp_window_scaling = 1
net.ipv4.ip_local_port_range = 1024 65535
net.ipv4.tcp_max_tw_buckets = 360000

net.ipv4.tcp_max_orphans = 3276800
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_syn_retries = 2
net.ipv4.tcp_synack_retries = 2
net.core.somaxconn = 32768
net.core.netdev_max_backlog = 32768
net.ipv4.tcp_max_syn_backlog = 65536
net.ipv4.tcp_mem = 94500000 915000000 927000000

# security setting
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_fin_timeout = 15
net.ipv4.tcp_orphan_retries = 2
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.accept_redirects = 0
net.ipv4.conf.all.secure_redirects = 0
net.ipv4.conf.default.secure_redirects = 0
net.ipv4.conf.all.log_martians = 1
net.ipv4.conf.default.log_martians = 1
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.default.accept_source_route = 0
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.default.rp_filter = 1
net.ipv4.tcp_syncookies = 1
net.ipv4.icmp_echo_ignore_broadcasts = 1
net.ipv4.icmp_ignore_bogus_error_responses = 1

# network traffic congestion control
net.ipv4.tcp_congestion_control=htcp

# I/O tuning
vm.dirty_background_ratio = 0
vm.dirty_background_bytes = 209715200
vm.dirty_ratio = 40
vm.dirty_bytes = 0
vm.dirty_writeback_centisecs = 100
vm.dirty_expire_centisecs = 200

# Buffer Overflow Protection in Ubuntu only
# Enable "No Execute (NX)" or "Execute Disable (XD)" in BIOS/UEFI
# Then run : sudo dmesg | grep --color '[NX|XD]*protection'
# If you see "NX (Execute Disable) protection: active" or similar, your
# kernel is protected from Buffer Overflow.

# Buffer Overflow Protection in RedHat/CentOS/Fedora only
#kernel.exec-shield = 1

# Enable ASLR
# 0 - Do not randomize stack and vdso page.
# 1 - Turn on protection and randomize stack, vdso page and mmap.
# 2 - Turn on protection and randomize stack, vdso page and mmap +
#     randomize brk base address.
kernel.randomize_va_space = 2