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

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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
19 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
12 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
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4answers
22k 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 ...
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1answer
17 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 ...
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1answer
25 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 ...
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4answers
14k 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
30 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 ...
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0answers
8 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
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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 ...
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3answers
109 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
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0answers
119 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 ...
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36 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 ...
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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 ...
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0answers
18 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
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8answers
106k 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
9k 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
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1answer
73 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, ...
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0answers
30 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 ...
2
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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 ...
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6answers
18k 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
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1answer
38 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 ...
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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 ...
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1answer
318 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. ...
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0answers
292 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
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0answers
55 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 ...
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1answer
544 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
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0answers
73 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
103 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 ...
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0answers
78 views

Ping RTTs vs UDP Ping Pong RTTs

Network Topology (wired): ServerA - 1Gb - Switch - 10Gb - Firewall - 10Gb - ServerB Pinging ServerB from ServerA shows round trip times (RTTs) of ~1.2 milliseconds. UDP packet 'ping pong' between ...
2
votes
0answers
128 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 ...
0
votes
1answer
388 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
19k 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. ...
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1answer
106 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 ...
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votes
1answer
73 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 ...
8
votes
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 ...
3
votes
1answer
258 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 ...
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0answers
308 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
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1answer
368 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
953 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
305 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
404 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 ...
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 ...
2
votes
1answer
903 views

ELB - High latency when enabling cross-zone balancing

I'm working on improve our infrastructure reliability in AWS and one of my tasks is enabling cross-zone balancing on our ELBs. Our ELBs receives around 20K request by second on rush hours as well as ...
0
votes
1answer
723 views

Lotus Notes Error - “Specified Network name no longer available”

I work for a bank who is using Lotus Notes email and during the transition from Windows XP to Windows 7 the Lotus Notes client was upgraded from Client 8.0.2 to 8.5.3. Given that these were the only ...
3
votes
1answer
2k views

difference between taskset and cpuset

I'm trying to reduce the latency of my linux network application. I've learned that there are two tools for "binding" a program to particular CPU core: taskset and cpuset. Which one should I prefer? ...
1
vote
1answer
875 views

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 ...
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2answers
446 views

Performance Tuning Linux [closed]

Performance Tuning/ Monitoring/Latency keeping in mind I see following 4 items & in each item they are lot of tools. CPU Memory IO Network What I see following tools we do use. vmstat mpstat ...
3
votes
2answers
1k views

Need ultra-low latency, how to minimize?

I have several Windows Server 2008 R2 machines that act as clients and are connected to another server in the same datacenter. I don't have access to teh server. I need to minimize latency between ...
1
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2answers
309 views

SMB Latency Issue with Multiple Users

We have a program that works by being shared over the network as a normal Windows Mapped Drive. You run the program from the mapped drive and it stores its files in flat file databases in that mapped ...