====== Kernel Tuning ======

This tuning i have used for dedicated DB server.\\
You can use it, as it is on any modern server, but please make sure to read note once.\\

==== ###### Optimization Dec. 22 2011 ###### ====

 
=== ## Reduce Swapping ===
<code bash>
vm.swappiness = 30
vm.dirty_ratio = 50
vm.dirty_background_ratio = 5
</code>
=== ## Prevent Syn Attack ===
<code bash>
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_syn_retries = 5
net.ipv4.tcp_synack_retries = 2
net.ipv4.tcp_max_syn_backlog = 4096
</code>
=== ## Enable IP Spoofing Protection ===
<code bash>
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.default.rp_filter = 1
</code>
=== ## Decrease tcp fin timeout ===
<code bash>
net.ipv4.tcp_fin_timeout = 15
</code>
=== ## Decrease the time default value for keep alive ===
<code bash>
net.ipv4.tcp_keepalive_time = 300
net.ipv4.tcp_keepalive_probes = 5
net.ipv4.tcp_keepalive_intvl = 15
</code>
=== ## Enable Fix for RFC1337 ===
 <code bash>
net.ipv4.tcp_rfc1337 = 1
</code>

<note warning>
## Not for Low memory system
</note>

=== ## Increase Read Buffer ===
<code bash>
net.ipv4.tcp_rmem = 8192 87380 16777216
net.ipv4.udp_rmem_min = 16384
net.core.rmem_default = 131072
net.core.rmem_max = 16777216
</code>
=== ## Increase Write Buffer ===
<code bash>
net.ipv4.tcp_wmem = 8192 65536 16777216
net.ipv4.udp_wmem_min = 16384
net.core.wmem_default = 131072
net.core.wmem_max = 16777216
</code>
=== ## Increase Number of incocimng connections ===
<code bash>
net.core.somaxconn = 32768
</code>
=== ## Increase max buffer for con. ===
<code bash>
net.core.optmem_max = 65536
</code>
=== ## Increase TCP queue lenght ===
<code bash>
net.ipv4.neigh.default.proxy_qlen = 96
net.ipv4.neigh.default.unres_qlen = 6
</code>
=== ## increase slots for tcp / udp ===
<code bash>
sunrpc.tcp_slot_table_entries = 32
sunrpc.udp_slot_table_entries = 32
</code>
=== ## increase uRPC datagram queue lenght ===
<code bash>
net.unix.max_dgram_qlen = 50
</code>