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

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1answer
16 views

TCP retransmission delays - lost acks

Maybe somebody will be able to help me out with this. I'm trying to find out if there is anything that can be optimized server-side to reduce delays in case of packet loss. Environment: Windows 2012 ...
0
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0answers
4 views

What could be the cause of this latency on IIS7 web cluster MVC?

Specs: Windows Server 2012 R2 IIS 7 .NET 4.0 MVC 3 application 2 servers in a cluster with load balancing enabled Oracle back end We have dozens of MVC3 apps hosted on this server, but only two of ...
0
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0answers
3 views

Super Slow (latency + speed) Wireless AP's, Suggestions? [migrated]

Looking for some advice, we have: Router: Asus RT-N66U, 2.4ghz wireless is disabled 2 Engenius ECB350 Access Points configured on Channel 6, 20mhz HT mode, 1 on each floor (900 sq ft each) Home is ...
-4
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0answers
19 views

Content download time always larger than connection time [closed]

I've tweaked nginx settings for a while, and just realized that the content download time probably always is larger than the connection time. Am I correct in that assumption? Thank you.
0
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1answer
34 views

Can high server's CPU usage cause high ping for clients? [closed]

Some users have high ping and they cannot play my multiplayer game due to it. My server application is causing CPU to always rise little by little and when I restart it, it drops. I am working on ...
8
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2answers
11k views

Limit incoming and outgoing bandwidth and latency in linux

I realise many similar questions have already been asked, but so far I've yet to find a solution to my problem. I have a virtual linux server (running Debian Squeeze) that I use for testing of ...
-1
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0answers
27 views

Amazon ec2 micro very high latency

I just set up an instance(nothing extra installed,no services running) on linux ami on a t1 micro. From india to singapore , the latency is 560+ ms. A few months back it used to be much less (<...
0
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0answers
35 views

How do I reduce private network latency below 0.5ms?

We are migrating from one host to another. Our cluster consists of 10 dedicated linux servers which must communicate on a private network. At the old host we observed latencies below 0.2ms between our ...
2
votes
1answer
161 views

SSH Client sporadically hangs for few seconds

On Ubuntu 14.04 LTS when I use SSH client, it hangs sporadically for few seconds every minute or so. no input is lost is just delayed. SSH -V OpenSSH_6.6.1p1 Ubuntu-2ubuntu2, OpenSSL 1.0.1f 6 Jan ...
1
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1answer
38 views

Why does SSHFS I/O latency test much faster than local RAID & NFS?

SSHFS tests for server I/O latency using dd returns very surprising results, so much so that I'm worried this might be some problem either with the test method or configuration. Test 1 on local RAID ...
0
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0answers
49 views

Is it Possible to Configure Receive-Side Scaling on an EC2 Instance Running Windows Server 2012 R2

Currently, I am experiencing some problems on getting a server to run efficiently on an EC2 instance. On my local machine everything runs as expected, but on AWS the servers experience some latency, ...
0
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0answers
25 views

How do I investigate latency between my app server and web server?

I have a Rails application running on Thin behind an Nginx instance. When I first start the application, requests are served in a reasonable time but after a few (identical) requests, this suddenly ...
0
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0answers
13 views

Find closest (in round-trip time) hosting to a particular serivce behind CDN

I'm using some service which is located behind CloudFlare CDN, and I need to achieve the lowest latency possible in two tasks: receive lots of messages out of WebSocket WAMP subscription with few ...
14
votes
4answers
25k views

Intermittently high ping times to router via Wi-Fi

On my local network there are (among others) 5 machines (running Debian Jessie or Arch) wirelessly connected to a Netgear WNDR4000 router. Below is a graph of the ping times to the router from each of ...
1
vote
1answer
19 views

Layout for aws services across regions

Looking for a method to evaluate best layout for services across AWS regions. My setup is compromised from 2 endpoint, a server in NY4 and client in Asia. Between them are 2 api hops and a web server....
0
votes
1answer
30 views

Is connect time all because of latency issue?

Server Question: I have been working on to increase speed of website of https://www.winni.in and I have came across a very strange phenomena. If anyone could, please explain about this. I was ...
20
votes
4answers
15k views

Why do mobile networks have high latencies? How can they be reduced?

I'm increasingly seeing mobile networking technologies being used to get internet access in areas where it is otherwise not available. While mobile networking is usually not yet viable as the primary ...
2
votes
1answer
43 views

How to debug linux latency issues under network load

I have 12 mixed Ubuntu 12/14 database Cassandra nodes. All nodes are baremetal nodes with SSDs, 1Gb network cards and are all colocated in the same DC (managed colo). Under light operation, the ...
0
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0answers
10 views

Latency on Rails App on Heroku

Images linked are screenshots of new relic status on my app. My app takes up to 12 seconds to first byte of render. In my understanding, the graph means rackspace is the reason for the application ...
3
votes
0answers
30 views

Monitor latency by IP on a bridge-enabled host

Is there a tool which captures packets, measure latency in realtime and display it with some IP filtering options for Windows ? My particular setup : Internet -> Router -> Host Master -> Host Slave ...
0
votes
3answers
110 views

use a offside proxy server to optimize site delivery?

Actually we have following setup for our website that gets traffic around the world: All JS, Images, Photos are stored on a CDN: Cloud Files ("Akamai light" powered). The WebApp server who send the ...
3
votes
0answers
170 views

Latency (wait ttfb) on EC2

My application is crawling a website. I use this crawler : https://github.com/rfussien/leboncoin-crawler On my dev environment, the latency is acceptable (3-4 sec) but on my prod server (ec2 T2....
0
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0answers
49 views

High latency from clients accessing SQL Anywhere backed application

Apparent high latency from clients accessing SQL Anywhere backed application The setup: Server: Running Windows Server 2012 R2 Standard /w Hyper-V role VMs on this server: -2 DCs -1 terminal server -...
0
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0answers
33 views

What is an efficient means to serve a dynamic website globally, in terms of latency? [duplicate]

We're using Amazon's AWS infrastructure. At one time, we did have a load-balanced setup across geographic regions, and our database cluster was divided between those regions. To reduce costs for the ...
0
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0answers
20 views

high ping6 latancy for cisco C3750

I have one cisco router with IOS software ( IOS Software, C3750 Software (C3750-IPSERVICESK9-M), Version 12.2(55)SE1). Recently, there is big ping latency, when I ping from one HP Gen6 SERVER which ...
42
votes
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. ...
6
votes
3answers
10k views

sssd and ldap authentication cache

On our box running OpenSUSE 12.2 we have installed OpenLDAP and sssd daemon. We are using these two services for user authentication. Recently we created a script which creates new web-users for our ...
0
votes
1answer
92 views

Long latency on Windows/IIS virtual hosts

We have a development server on which we have about 10 identical virtual sites. Whenever we pull up one of the sites, it is very slow (up to 30 seconds for the login page to show up). Once logged in, ...
0
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0answers
32 views

Network issues or tcp stack load

I am running a NoSQL (aerospike) cluster on a set of identical hosts (ec2). Once in a while one of them would start timing out on queries and connections, and pings to it would go from < 1ms to 20-...
2
votes
1answer
1k views

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 ...
15
votes
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 ...
0
votes
1answer
40 views

monitor and log speed of a program working with network files

We are using a CAD program on multiple computers in a network. All files and projects are stored on a network storage. The users moan about long waiting times while opening from and saving to the ...
8
votes
3answers
2k views

Do changes in SPF records take time to propagate?

I'm setting up SPF records for my domain, and am not getting the results that I expect. It's quite possible I'm making some sort of mistake, but first I'd like to ask: does it take time for the ...
1
vote
1answer
326 views

Amazon's ELB + Instances = High Latency?

I have a single instance running which is sitting behind their load balancer. When I use apache's benchmark utility and point it at the instance the response time is more often than not, under 50ms. ...
0
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0answers
353 views

Sometimes unable to tune Linux TCP stack for improved high-latency performance

I have been unsuccessfully trying to apply the TCP Tuning techniques discussed at http://fasterdata.es.net/host-tuning/ As you'll see when you read through the entire question, sometimes the es.net ...
2
votes
0answers
60 views

Azure Web App Latency

I have a simple Azure Web App setup using a single Standard Small Instance type in Central US region. The site itself is running a node.js website. I noticed google crawl was reporting average ...
1
vote
1answer
551 views

What could this extra 50ms latency be on my unbound DNS resolving server (Fedora)?

I have a discrepancy in query latency. It's not a problem, it's just strange enough to worry me. Client machine (Fedora 18) runs unbound-1.4.19-1.fc18.x86_64. Server machine (Debian 7 testing) runs ...
0
votes
0answers
80 views

ping timeouts with light http traffic on T1 connection

I have a T1 over copper connection and started to notice that if I run ping while loading an http page (http://google.com) I get intermittent timeouts in ping. Is this normal? I expected some ...
2
votes
1answer
113 views

Windows 2012 Shared Drives Odd Latency Issue

I have a Dell T110 II running ESXi 5.5 with a Windows 2012 R2 instance running with the following roles: ADDS DHCP DNS File/Storage Svcs WSUS I have two shared folders -- Scans and Data -- which ...
0
votes
1answer
436 views

Ubuntu Trusty: virt-manager performance over WAN… 40+ secs freezes

I'm using the virt-manager GUI 0.9.5-1ubuntu3 on my laptop running Ubuntu 14.04 against a server located some distance away (same OS) and getting rather unpleasant performance. Laptop-server pings ...
7
votes
1answer
21k views

How to troubleshoot latency between 2 linux hosts

The latency between 2 linux hosts is about .23ms. They are connected by one switch. Ping & Wireshark confirm the latency number. But, i dont have any visibility into what is causing this latency. ...
-1
votes
1answer
115 views

Why the latency increases on highload? [closed]

We have a system built on AWS. We use Beanstalk, we have autoscaling, our database (mysql) is hosted on RDS. We use apache and php. We wanted to test our system on highload. So, we chose large ...
-1
votes
1answer
80 views

How to reduce latency? [closed]

I am looking to build something where you can have a workstation/server in one location, and access it remotely using a video stream of the screen to do as you wish. My reason for wanting low latency ...
3
votes
1answer
277 views

Brocade DCX 8510 inter DC latency - understanding OIDs to find L1 issues

Trying to determine if there is some intermittent inter DC latency on the FC links, but only have access to the OID counters for the DCX 8510. Since it is a L1 link over DWDM there are no stats from ...
0
votes
0answers
350 views

Getting chunks of high ms when pinging local / external IP addresses?

I am having difficulty identifying what a specific problem with one of your vlaned networks. They have a voip phone which regularly cuts out during long phone calls. I have done several ping tests ...
0
votes
1answer
405 views

OpenVPN + Scrambled patch on Amazon EC2

Yesterday I deployed a regular OpenVPN installation on Debian Squeeze / Amazon EC2. The VPN server is in Singapore and I connect to it from China Mainland. Later on, after some tests I had to start ...
3
votes
1answer
1k views

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 ...
1
vote
1answer
319 views

My redis' fork time is slow and impact query performance a little. What should I do to check?

I used redis with RDB option only. It used 2GB of memory. When it forked, it used about 10 seconds to completely save the file. When I check up with redis.io site, I found this latency stat: - Linux ...
0
votes
2answers
461 views

extreme ping latency in WDS network

I have setup a wireless network at work office with the following config: 192.168.1.1: TP-Link 941 Router, Root AP, connected to internet 192.168.1.2: TP-Link 901 AP, WDS Repeater, connected to 192....
5
votes
3answers
4k views

Akamai vs smaller CDN for small/medium-size ecommerce traffic? (caching, latency, NetStorage)

The small/medium sized online retail company I work for uses Akamai as our CDN for static images, but I'm wondering whether it might be hurting rather than helping and, if it's suboptimal, what we ...