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tcptuning
====== Differences ====== This shows you the differences between two versions of the page.
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tcptuning [2011/04/23 00:36] sbwood |
tcptuning [2011/06/11 00:14] (current) sbwood |
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| ====== TCP Tuning ====== | ====== TCP Tuning ====== | ||
| - | |||
| By default, Centos used the following TCP parameters: | By default, Centos used the following TCP parameters: | ||
| Line 6: | Line 5: | ||
| Click [[http://www.frozentux.net/ipsysctl-tutorial/ipsysctl-tutorial.html#AEN454|here]] for a description of all of these parameters. | Click [[http://www.frozentux.net/ipsysctl-tutorial/ipsysctl-tutorial.html#AEN454|here]] for a description of all of these parameters. | ||
| - | <code> | + | |
| + | Other helpful sites: | ||
| + | [[http://www.speedguide.net/articles/linux-tweaking-121 | SpeedGuide.net]] | ||
| + | |||
| + | [[http://www.psc.edu/networking/projects/tcptune/ | PSC High Performance]] | ||
| + | |||
| + | <code> | ||
| + | |||
| $ sysctl -a | $ sysctl -a | ||
| Line 94: | Line 100: | ||
| sysctl -w net.core.netdev_max_backlog=30000 | sysctl -w net.core.netdev_max_backlog=30000 | ||
| sysctl -w net.ipv4.tcp_congestion_control=htcp | sysctl -w net.ipv4.tcp_congestion_control=htcp | ||
| + | </code> | ||
| + | |||
| + | [[http://www.speedguide.net/articles/linux-tweaking-121|SpeedGuide]] also recommends the following settings: | ||
| + | <code> | ||
| + | sysctl -w net.ipv4.tcp_sack = 1 | ||
| + | sysctl -w net.ipv4.tcp_window_scaling = 1 | ||
| + | sysctl -w net.ipv4.tcp_timestamps = 0 | ||
| + | </code> | ||
| + | Although setting the tcp_timestamps = 0 is controversial (and we chose to leave it enabled): FasterData points out that some alternative congestion control protocols require accurate timestamps. | ||
| + | |||
| + | The Ethernet cards we are testing with are: | ||
| + | <code> | ||
| + | eth1: Tigon3 [partno(BCM95704A7) rev 2003 PHY(5704)] (PCI:66MHz:64-bit) 10/100/1000Base-T Ethernet 00:e0:81:2c:5e:bd | ||
| + | eth1: RXcsums[1] LinkChgREG[0] MIirq[0] ASF[0] WireSpeed[1] TSOcap[1] | ||
| + | eth1: dma_rwctrl[763f0000] dma_mask[64-bit] | ||
| + | </code> | ||
| + | |||
| + | Also, we will experiment with the MTU (using Jumbo frames of size 9000): | ||
| + | |||
| + | <code> | ||
| + | ifconfig eth1 mtu 9000 | ||
| + | </code> | ||
| + | |||
| + | And to test: | ||
| + | <code> | ||
| + | ping -M do -s 8992 192.168.0.3 | ||
| </code> | </code> | ||
tcptuning.1303518962.txt.gz · Last modified: 2011/04/23 00:36 by sbwood
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