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Questions tagged [latency]

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

Latency is the time period between a signal being sent and a signal being received. In computer networking this can be the time between a sending of a packet and receiving of a packet.

To illustrate we can use the ping command:

PING google.be (173.194.66.94) 56(84) bytes of data.
64 bytes from google.be (173.194.66.94): icmp_req=1 ttl=47 time=76.6 ms
64 bytes from google.be (173.194.66.94): icmp_req=2 ttl=47 time=74.8 ms
64 bytes from google.be (173.194.66.94): icmp_req=3 ttl=47 time=79.6 ms

The latency here is 76.6 ms.

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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 that our data center is on the West Coast of the…
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How do I test my internet connection speed via a Microsoft Windows Terminal?

I currently have two production servers. One running Windows Server 2003 and the other Windows Server 2008. When I open the Reliability and Performance Monitor I see a Network section that only goes up to 56Kbps see the image below. It concerns…
nu everest
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Why the time taken to fetch results of a query for 10,000 times from a RDS is so uneven? (experiment)

tl;dr : Why the time taken to fetch results of a SELECT statement for 10,000 times from a RDS when requested from an EC2 is so uneven? Updated the question with results of small and medium RDS servers While experimenting with AWS for checking time…
Sumit Sinha
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what is acceptable datastore latency on VMware ESXi host?

Looking at our performance figures on our existing VMware ESXi 4.1 host at the Datastore/Real-time performance data Write Latency Avg 14 ms Max 41 ms Read Latency Avg 4.5 ms Max 12 ms People don't seem to be complaining too much about it…
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Amazon EC2 and Amazon RDS in Same Network

We have deployed our application in EC2 instance and our database is in RDS which is db.m2.2xlarge. I see some minor slowness in our application when compare to our QA environment where has both application and our DB server. Though Prod server has…
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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 to run a local MySQL instance on each app server…
Andy
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Tool to test MySQL latency

I want to compare the latency of my web application against two different MySQL servers: one a local machine and one hosted via Amazon RDS. What would be a good, free, and (preferably) easy tool to use to test MySQL latency? I have both Windows and…
user35042
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Combining Heroku with custom external services (e. g. Varnish or Postgres on EC2)

I'm planning to set up a Django site on Heroku. It will run on Heroku's Cedar stack, which allows Python apps, but doesn't include or support HTTP upstream caching with Varnish like the other stacks do. It will be a very read-heavy site and I'd like…
mkai
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How to find the lowest latency midpoint between two geographic locations?

I'm looking for a geographic location (not service) to host internet services that will give me the lowest latency on connections from two other locations. How would I best determine the most ideal midpoint?
Ehtyar
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Hyper-V guests: intermittent latency

I am seeing latency on a Hyper-V host and its guests lately. When I run ping -f from a Linux prompt, I see the dots "pulsate" like a heartbeat indicating 2 successive latency spikes within 1 second followed by about 1-1.5 seconds of "normal"…
the-wabbit
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Diagnose cause of long running requests in IIS 7.0

We are running an ASP.NET web application on IIS 7.0, Windows Server 2008 R2, with SQL Server 2008 R2 for DB. On weekends, when the traffic is high, the request queue length in the IIS servers increase (up to 800 requests) and then drops, every…
Shlomi Fruchter
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Networking Hardware Suggestions For Low-Latency Networking

We've come to the stage of our project where we want to take the software to the next level, generally response times of 20µs or less. Software wise its as good as it gets (though there's room for a little more improvement), however now we're…
Seminar
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low latency TCP settings on windows 2008 R2

I am running a third party software on a W2008 server. This client connects to a server via TCP. The average ping times between the two are 1ms. However, when I check the tcp connection in resource monitor for the app it shows the latency as 20ms. I…
user70303
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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 everything to set it up except the network latency test. I…
Sam
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Network latency -- how long does it take for a packet to travel halfway around the world?

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 can I expect for a user to get a single packet if they're in…
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