Latency is the time period between a signal being sent and a signal being received

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Another benefit of Lighttpd in front of Apache

I have read in a site that another benefit of having Lighttpd in front of Apache is lower number of child processes. Lighttpd will handle keep-alive and client requests while child processes of Apache ...
2
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3answers
672 views

TCP handshake latency

I have 2 machines on a 100 Gb/s LAN which talk to each other over TCP. When I do a tracert or a ping from the client to the server, even a large ping, I get an answer in less then 1 ms. However, when ...
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5answers
5k views

OpenVPN over TCP, terrible latency but only on Win7 x64

I know TCP encapsulated over TCP is a terrible idea in general, but I can deal with the occasional decreased performance and MTU issues, and the snowball effect TCP within TCP provides where error ...
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2answers
8k views

Internet latency map

I would like to see a latency map, showing the lowest latencies achieved between various destinations around the world. What is for example the lowest latencies achieved between Denmark and India. ...
2
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2answers
199 views

How remote warfare works when even my satellite TV and remote server has latency? [closed]

This question is after reading this article. My title asks it all. How the connection for this remote warfare works with a absolutely low network latency (which i believe is essential to achieve a ...
0
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2answers
3k views

Network latency — how long does it take for a packet to travel halfway around the world? [duplicate]

Possible Duplicates: How does geography affect network latency? How much network latency is “typical” for east - west coast USA? If I'm hosting an app in NY, what kind of delay ...
76
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8answers
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How much network latency is “typical” for east - west coast USA?

At the moment we're trying to decide whether to move our datacenter from the west coast to the east coast. However, I am seeing some disturbing latency numbers from my west coast location to the east ...
0
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2answers
24 views

Why same HTTP operation's connections number difference under the same surrouding?

Under the same pc to operation one HTTP operation. Lan operation has less connections number than wan's (or add network latency). Why is it so like as I said? What determines how many connections ...
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2answers
2k views

use of tcp_delack_min on redhat linux (kernel 2.6.18)

we're moving from Solaris to Redhat Linux, and trying to duplicate our low-latency setup, that, on solaris, includes the ndd settings related to TCP NO DELAY, and NAGLE ALGORITHM. I got the impression ...
0
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1answer
667 views

fast way to find network user computer on domain hogging all wan bandwidth

i have a network of about 40 domain users and i have huge latency wan issues, like 1400ms for google.com pings. I have noticed that the problem goes away after everyone goes home for the day. I would ...
2
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3answers
3k views

Terminal server performance over high latency links

Our datacenter and head office is currently in Brisbane, Australia, and we have a branch office in the UK. We have a private WAN with a 768k link to our UK office and the latency is at about 350ms. ...
0
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1answer
623 views

IRP_MJ_WRITE latency up to 15 seconds

We have written an application that performs small (22kB) writes to multiple files at once (one thread performing asynchronous queued writes to multiple locations on behalf of other threads) on the ...
0
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1answer
92 views

Benchmark of provisionning delays of various cloud providers

Cloud computing supposedly lets you instantiate on-demand processing power through additional VMs. The allocation process is frequently advertised as fast without further details. My personal ...
3
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1answer
397 views

Can Linux RAID 1 account for high latency?

Scenario: we're running a large (3TB total in cluster) Solr installation in EC2. I'm only concerned about disk performance on the read side of things. We suspect that we are limited by disk I/O and ...
0
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4answers
195 views

Is asymmetric latency common in practice?

This is a follow-on to a question posted on stack overflow about whether it is possible to determine the one-way latency of a point to point connection without using externally synchronized clocks - ...
0
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6answers
3k views

Why am I getting long TCP connect latency on connect in a LAN (over a cross!)?

I am measuring a time of about 100-150 milliseconds from sending TCP SYN to getting SYN/ACK, between two linux computers connected to the same Cisco switch. Consider: The machines are very powerful, ...
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1answer
2k views

Can't stream media on network

Long story short, at our office network, we can't really certain things. Last.fm downloads an entire song before playing it, and YouTube loads and then all of a sudden the entire video is loaded and ...
2
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2answers
3k views

Should I be concerned about my iSCSI SAN traffic?

I have a meeting with DELL today to discuss some of our SAN setup and I want to be able to talk about what I am seeing. We have an average Latency of 20ms. I'm attaching a screenshot of what it is ...
2
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3answers
1k views

Route traffic to node with lowest latency in HAproxy

Is it possible to route requests via HAproxy to a server that has the lowest latency from the source IP? This seems like a much needed requirement but I can't seem to find anything. My problem is ...
2
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2answers
488 views

How much overhead does the Chinese firewall add to a network conversation?

Does anyone have any stats on this? I'm mainly asking from a private network perspective (assuming that they are affected by the firewall as well). That is, all of my apps that are in use in China ...
2
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6answers
6k views

MySQL performance over a (local) network much slower than I would expect

MySQL queries in my production environment are taking much longer than I would expect them too. The site in question is a fairly large Drupal site, with many modules installed. The webserver (Nginx) ...
42
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8answers
111k views

Why is the response on localhost so slow?

I am working on a tiny little PHP project for a friend of mine, and I have a WAMP environment setup for local development. I remember the days when the response from my local Apache 2.2 was immediate. ...
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3answers
2k views

Does routing distance affect performance significantly?

When I say routing distance, I mean on a global scale. For instance, if my target audience is in China, do I look for a host within China?
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6answers
19k views

How does geography affect network latency?

I have the option of hosting our database/web server at a managed hosting company on the East Coast (US) or one on the West Coast (US). Our company is based out of New York City, and both hosting ...
2
votes
2answers
837 views

Configuring Squid to choose a peer cache based on latency to destination website?

Is there any way to configure Squid to choose a peer cache based on the latency in communication to the http port on the destination webserver? For example, let's say we have two Squid caches - ...
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4answers
398 views

Bandwidth throttling software

I need to be able to simulate high bandwidth/high latency/high packet loss on my pc for the purpose of testing the software that I'm writing. I've seen some software that you can install on a ...
0
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2answers
256 views

How can I determine the fastest memory based on latency and bandwidth?

I've got some older hardware that needs a memory upgrade, and I was trying to determine what RAM would be the fastest on the platform. My platform takes DDR2 667MHz which is (slightly) more ...
4
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3answers
219 views

run local MySQL instance for fast mysql_real_escape_string calls

Currently all MySQL data/API calls are handled by a remote DB cluster (i.e. network latency is a factor in total script execution time). To reduce execution time in this context, would it be sensible ...
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4answers
795 views

What latency can I expect with SDSL?

My company is considering moving some internal infrastructure to my location, that will be accessed, over vpn, from other company locations. Currently we are reluctant to do this because of the ...
2
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9answers
3k views

Measure data transfer throughput?

How can I benchmark the network transfer speed of my servers? We already have an existing file server, but it is fairly old. We recently got a donation of a (relatively) newer P4 box, and I wanted to ...
0
votes
1answer
358 views

SONET ADM Latency

Is there published documentation on best-case and worst-case latency added by SONET ADM equipment? Specifically I'm looking for the latency I could expect to be added to an OC-3 piped through these ...
2
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4answers
6k views

Level 3 Communications Monitoring

Does Level 3 Communications offer any type of map of current network status? It seems our connection here is getting high latency through their network. Also what is the experience asking them ...
2
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11answers
3k views

VPN drops (DPC latency issue)

I am using VPN to connect to work. I am used to listening to streaming music when I am in the office, but when i do that over the VPN, the connect drops. So, no big deal, I just won't use the ...
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2answers
2k views

How much latency does raid 5 add to transfers?

Your bandwidth/throughput should go up with raid 5, but you will take a bit of hit in latency after you over run the cache, since you need to calculate the parity. Has anybody done a latency test ...
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8answers
7k views

How can I control the network latency?

My company is developing a network software and its network stability is very important. So my supervisor want me to set up the testing environment for our QA team. I can take care of almost ...
8
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4answers
14k views

Tuning NFS for minimum latency

How can I achieve low latency for NFS exports in order to e.g. have developers work nicely in Eclipse/Visual Studio with their workspaces mounted over NFS?
5
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8answers
7k views

Latency in Internet connections from Europe to USA

I'm looking for a (cheap) Web hoster. Basically all the hosting providers that I can find, and match my requirements are located in the USA. But my target audience is in (Western-)Europe, I know for ...