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10 Tips For Boosting Network Performance
snydeq writes "InfoWorld's Paul Venezia and Matt Prigge provide hands-on insights for increasing the efficiency of your organization's network. From losing the leased lines, to building a monster IT test lab on the cheap, to knowing how best to accelerate backups, each tip targets a typical, often overlooked IT bottleneck."
Unplug wires in network closet.
I learned from the BOFH that the fastest backups are written to /dev/null.
"This post contains words, known to the State of California to cause thought. Wash brain thoroughly after reading."
Plug wires in again in a more colorful way.
Stop your IT Department from visitting Slashdot
Seriously, does anyone backup to tape anymore?
I Am My Own Worst Enemy
Just give Eric Schmidt a call, tell him you have nothing to hide from his company or the government and they will replace all your machines with shiny new Google Chrome OS based "Net tops", put all your data on their servers, give you a brand new direct fibre optic connection to their nearest office and all they want in return is the ability to meticulously sift through your data in order to find the best way to bombard you with text-based ads.
Everything is more shiny with Google.
What reason is there to run T1/T3 anymore? I know, by definition, the regulation over T1/T3 guarantees reliability. I have dumped T1's and switch to 2Base-TL (aka Metro Ethernet) and it is extremely reliable. For me, the "more reliable" argument doesn't hold much. The latency is very, very good -- often below 10ms. Even if the network goes down, I can afford some sort of backup link. I'm paying under $1,000/month for 10mbit (symmetrical). The footprint for 2Base-TL is pretty good because it is based on DSL technology. It doesn't have the reach that T1's have, but it isn't bad. The big difference is that is spreads the signal over multiple pairs of wire (in my case, 8 pairs) instead of a single pair.
If your company has T1's, shed yourself of the "regulated" links and check out 2Base-TL. You will be glad you did.
Get rid of fat clients, that will do wonders to reduce your network bandwidth needs out to the customer. Then beef up the datacenter network.
---- Booth was a patriot ----
Slow down your internet connection to a single 56k line... then people will stop trying to use it to look for porn and all the useless crap searches they do on google... You'll also save some money with the monthly bills!
once I told a coworker about emule. He downloaded and installed it. The next morning the CFO comes to me.... "Have you ever heard about emule"...the infastructure was screwed up, but instead of fix it they waited for p2p to bring the network to it's knees. The best way to test a network is to see how many simultaneous p2p connections it can handle before crapping out. Needless to say there were some consequenced for that employee.
i think you misunderstood.
Know your apps means knowing their bottlenecks and how to alleviate them.
Some apps have high sustained disk reads, some writes.
Some have high amounts of random reads, some randoms writes, some both.
Some apps are I/O bound, some memory bound, some CPU bound.
The source of the app has nothing to do with your ability to monitor the operation of the app and determine its infrastructure needs.
It frightens me to think that there are people getting paid to take care of enterprise systems that would not already know everything in this article. Mostly, it reads like a thinly veiled ad for VMWare products.
Ask Slashdot: Where bad ideas meet poor googling skills.
It depends, we have some sites that have done very well with cable providers on business class accounts (I assume those that have separate channels for business class), and less so with others. Our biggest problem has been the lack of any teeth to an SLA when we did have problems, which is why I would never move our HQ which has nearly half our people and which hosts remote access for the rest. For a remote office where they can always fall back to 3G tethering if they have an outage for a day or two and use our Citrix farm it's a great way to get bandwidth on the cheap.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
Run remote desktops. Bandwidth consumption to the desktop drops dramatically.
Run your heavy network I/O over the switch stacking fabric, where you've got shit loads of bandwidth. Channel bond.
Separate access ports/switches and storage network ports/switches. Use jumbo frames on the storage network, but don't route them.
Prefer shared memory first, then unix domain sockets over TCP/IP/LAN over WAN. Microsecond (or better) latency vs milliseconds or seconds.
Dedicate servers to applications, take advantage of copy on write & modern memory management.
Let your VM management hold a significant proportion of dirty pages. WTF is the point of loads of RAM if you insist on running at disk speed? But do use a logged filesystem.
Use a load management system. Grid Engine, Condor etc.
Deleted
... and if you think it is about latency you are mildly retarded, as are the writers of this general knowledge article.
Leased lines in general have better SLAs but that isn't even much of a point anymore as they cheaper products "claim" to have similar ones. The difference here is how good is that business class dsl/fiber support at 2am? What are the odds they are actually going to be willing to send someone out to the telco closet right away if there is an issue? You buy leased lines because you need *real* support of the SLAs... not this, "well we were down for 5 hours, so how about we credit you a day off!" bullshit.
It's really scary for what passes for "good advice" these days.
--- I do not moderate.
That is almost exactly five 9's of up-time. Sounds like they met the standard guarantee.
Learning about brewing beer, by brewing beer.
Interrupt Moderation = Disable
Here's a real tip, disable Interrupt Moderation on your Network Adapter Cards to achieve greater bandwidth, as much as 100%+, and lower latency (the two measures of network performance) at the expense of processor utilization due to more hardware interrupts that have to be handled.
Instructions: In Windows open up Control Panel, Network and Sharing Center, click on Change Adapter Settings, open Properties on your Local Area Connection (sometimes #2, #3, or something if you have more network cards), click on the Configure button, then the Advanced tab, select Interrupt Moderation, change the value to Disabled, while there look for any settings with the word Offload and enable them all, and then click the OK button to make the changes. This will restart your network card driver and make the settings effective.
Most network cards from popular manufacturers such as Intel, Broadcom, Realtek, etc. hold network packets in a buffer until enough time goes by before raising a hardware interrupt and telling the processor, operating system, and network driver that there are packets waiting to be serviced. By disabling Interrupt Moderation you instruct the network driver and card to raise the interrupt every single time a packet comes in, thus making your processor service the network card much faster thus decreasing latency on the packets held in the buffer and also increasing bandwidth by allowing more packets to flow through faster. This increases your processor utilization by a significant amount 10-30% but if you have a recent dual, quad, hex, octo-core processor and recent network drivers that are multi-threaded with multi-core support and have Receive Side Scaling support then the increased processor utilization is negligible to your computer and if you are running a network server then network performance should be a priority anyway.
I have personally seen and tested corporate and home LAN environments using Fast Ethernet 100 Mbit/s (~11 MByte/s) go from slow 6-7 MByte/s to 10-11 MByte/s throughput, and Gigabit 1,000 Mbit/s (~100 MByte/s) go from ~30 MByte/s to 95-98 MByte/s speeds due to these changes. No other network driver setting had as much performance impact as Interrupt Moderation.
IEEE 802.1AX (aka 802.3ad, Cisco EtherChannel)
For advanced network performance improvement look at link aggregation (channel trunking, link bonding, etc.) using the IEEE 802.1AX (aka 802.3ad, Cisco EtherChannel) protocol support in your Intel and Broadcom network adapters using their Advanced Configuration Utilities on your servers to bundle from 2-8 Ethernet network adapters into one trunk to increase your performance. Just tell your network administrators to enable those features on your ports and find out if they are able to do it if your links are going to the same switch or if they have virtual switching enabled in case your links span switches. Just think about 4 x Gigabit performance if you bundle all 4 NICs on most servers.
NetCPS
You can test your own network performance with this simple but great utility called NetCPS. Just be sure to disable Interrupt Moderation on both of the computers on your LAN that you will be using for the performance testing otherwise you won't be able to achieve these numbers if one of the computers can't handle the data as fast as the other one. Try it with your laptop and desktop for example.
NetCPS - is a handy utility to measure the effective performance on a TCP/IP network.
Just execute "netcps.exe -s" on the listening system and then do "netcps.exe computername " on the other computer to use the utility to test the throughput bandwidth. For Gigabit you can use the "-m1000" switch to increase the transferred amount to 1,000 MBytes instead of the default 100. Below is an example.
Indeed. Take it from someone running a web site on a "Business Cable" connection, it sucks ass. It runs over the exact same system as residential traffic. The only difference... I pay more (a lot more) but get almost exactly the same service. Sure, it says 1M up on paper but they (TW) start dropping traffic at half that -- and that's how they have the network configured.
We switched to a T1 from Speakeasy (resold Covad.) It's 1.5M in both directions all the time; no traffic ever gets dropped. It doesn't drop everytime the power flickers (TW's too cheap and lazy to put(replace) batteries out in the field.) I'll agree it's slow by modern standards, and it's about 3x as expensive, but it works all the time -- and when it doesn't people move their ass to fix it.
When /dev/null starts giving access to all the files it has gobbled up over the years I imagine would be like the gates of hell opening. Dennis Ritchie as pestilence will ride a black horse made of swarming bits astride with other famous Unix dudes (imagine your own!). Sysadmins who have been practicing the arcane arts of administrating access to Hell's one and only 9600 BAUD BBS running Minix will rise hungry for bandwidth, porn access and hot pockets.
An Education is the Font of All Liberty
RFC 1925
Cheers,
Dave
They that can give up essential liberty to obtain a little temporary safety deserve neither safety nor liberty.
Ben
insmod e1000.ko InterruptThrottleRate=1 (Mode 1)
insmod e1000.ko InterruptThrottleRate=0 (ITR off)
insmod e1000.ko InterruptThrottleRate=8000 (Fixed value for all I/O patterns)
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http://download.intel.com/design/network/applnots/ap450.pdf
Nice informative post, interrupt moderation sure sounds interesting. Link aggregation, however, is not as useful as it sounds for the following reasons:
1. Hardware link aggregation (link aggregation supported in silicon) works by hashing, not by distributing packets evenly across all links that are aggregated. If you can spare some time to ponder about this for a moment, you will be able to see why hashing is used. In real life situations, 4 x 1Gbps links aggregated together never equals 4Gbps throughput.
2. If link aggregation is handled by the software (which is most likely the case if aggregating multiple NICs on a server) then all it really provides is redundancy. It is very difficult for an average server to process 1Gbps of incoming traffic, let alone generate 1Gbps of worths of traffic. Not to mention the read/write speed of the storage device(s) used in the server.
(Unless it's using PCIE SSDs in RAID configuration, which would be very interesting and I am dying to find out the throughput of such a configuration!)
For once I actually know what I am talking about, so maybe I should have created an account before posting this one.