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

learn more… | top users | synonyms

0
votes
0answers
188 views

Unexplained Packets being dropped

I have two servers one sending large amounts of data to the other, we are noticing that one server is sending data to the other but the receiving server is missing some of the data or packets. I am ...
1
vote
0answers
59 views

Latency on intermediate network

For the past week I have noticed that most of the times pages running on my server are very slow. Sometimes they load quickly, but only about 15% of the time. Using an online traceroute tool I have ...
2
votes
2answers
2k views

Disk latency within a virtual machine

I've been looking at some performance issues on a clustered virtual machine in our organisation. Actually this problem seems to affect most of the virtual machines I have looked at. Both host and VM ...
0
votes
1answer
213 views

Unicorn rails server with Apache

I'm looking for the best setup to use in conjunction with Unicorn. Are there clear advantages or disadvantages to using Unicorn rails server with Apache? Should I consider using NGINX? I'm concerned ...
2
votes
0answers
443 views

High latency on domain with CDN

High latency on domain with CDN I have problems with latency on my server, these are the tests I made with blitz.io Latency album http://imgur.com/a/bCmwo I would uploaded images here but it ...
2
votes
1answer
291 views

Hosted Network Latency

Background I have a new hosted, dedicated database server behind a dedicated firewall (Cisco ASA 5505 Sec+). The plan is to have a virtual (aka "cloud") web server or two on the other side of the ...
1
vote
1answer
745 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 ...
3
votes
2answers
264 views

Appropriate network monitoring tool(s) for logging hiccups [closed]

I have a customer who has problems with our software crashing from time to time. Unfortunately, if you unplug the network cable in the middle of a transaction our software will crash every time and ...
-2
votes
1answer
174 views

Is it bad for latency to have ping running 24/7? [closed]

I want to display my avg latency time for whatever connection I currently have to the internet in a widget. Would having ping run continuously make my connection suffer?
0
votes
0answers
57 views

2 cisco 1941's, high latency during low network load

We have a point to point connection between 2 cisco 1941, the weird thing is that during low bandwith usage we experience high latency (peaks of 200+ ms, when 8-20 is normal) we currently use a ...
1
vote
0answers
368 views

how to disable MSI on tg3 driver?

got some new HP DL380p G8 for Centos. What's the correct options to disable MSI for the onboard Broadcom NICs? I tried disable_msi in modprobe.conf.local and it doesn't work. Thanks Will
1
vote
1answer
437 views

Latency, Nginx & PHP-FPM

I have a high load dynamic PHP web service which I have recently moved from Apache2 to Nginx and PHP-FPM. I am finding that the average request latency has increased from 0.5s to 1s since the move. ...
0
votes
1answer
190 views

35 times increased latency between data send rate of 1 millisecond vs 100 microseconds. WHY?

Experiment hping -S --data 100 -c 100 10.56.1.2 -i u100 round-trip min/avg/max = 0.5/14.0/15.8 ms hping -S --data 100 -c 100 10.56.1.2 -i u1000 round-trip min/avg/max = 0.3/0.4/4.8 ms Observation: ...
7
votes
2answers
5k 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 ...
0
votes
0answers
89 views

how to determine whether network switching equipment latency is OK for VDI delivery?

Is there a good (proper) way to test whether network switching in place is good enough for VDI delivery? I read a Cisco UCS whitepaper that stated that they observed 3.2 ms latency across their test ...
1
vote
0answers
330 views

FTP Transfers Slow Between 2 Servers

Between 2 dedicated servers, hosted in 2 different DCs (different companies), the FTP upload speeds are always much slower than the max connection speed. Specs: Windows 2008 on both. Quad core/8 GB ...
7
votes
1answer
4k views

High latency/drops between Cisco switches in two locations. How to troubleshoot?

I'm receiving user complaints about poor network application performance between two parts of a large warehouse facility. The software is a curses-based terminal application running on a Linux server. ...
3
votes
2answers
4k 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 ...
2
votes
3answers
1k views

Measuring network latency

I want to measure performance of the network, especially latency. We are performing stress tests of a system that sends live audio / video data over the network. When there are multiple simultaneous ...
0
votes
1answer
155 views

Best practices on lowering latency between two endpoints [duplicate]

I would like to know what tools or what kind of calculation should be made in order to find the lower latency possible between two points physically distant. For example: Ping time from Europe to ...
0
votes
0answers
37 views

reduce initial SSH communication messages

The situation: we have some manager servers in Japan which connects to servers in Amsterdam. Since the latency between JP and EU could reach 300ms, the initial login can take up to 6 seconds. Although ...
0
votes
1answer
65 views

Effect of latency on page load

What effect can a latency of 100 ms have on a page load time? If a 100 KB file is served from two locations with latencies of 100ms and 200ms respectively, will the difference in load time be just ...
5
votes
2answers
103 views

Trans-atlantic VOIP

We're a Canadian business on the east coast and will soon be opening up a new call centre in Australia. This new call centre will be handling our graveyard shift and will be overlapping with the ...
0
votes
1answer
156 views

Low Latency for Google compared to servers located with in my country [closed]

When i ping google.co.in its showing 11.1 ms as average ping www.google.co.in PING www.google.co.in (173.194.36.63) 56(84) bytes of data. 64 bytes from bom04s02-in-f31.1e100.net ...
1
vote
0answers
257 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. ...
-2
votes
2answers
514 views

Remote Desktop Software with low latency for thin clients [closed]

I'm currently using a thin client with the following specification: I am searching for Remote Desktop software that will allow me to have a very low latency for audio quality on my thin clients. ...
-1
votes
2answers
3k views

Can VPNs reduce latency? [duplicate]

I've found a common subject in forums asking about using VPNs to reduce latencies between the gamers and the game servers. I've even found some blog posts confirming this. From my understanding, ...
-1
votes
3answers
656 views

How to compare RDP latency?

For a remote Windows desktop solution, accessed from Las Palmas de Gran Canaria, I want to evaluate various options. What currently comes into my mind: EC2, Ireland Azure Virtual Machine, Ireland ...
0
votes
2answers
437 views

Why my server request takes 28 Second to get response?

I have a Wordpress website on a Godaddy server having at http://kerala.letmeshare.org. When I request to get this website this takes almost 28 sec to get reply. Because of this I made a complete ...
0
votes
1answer
433 views

Extremely high apache 2 initial response time, no system load

I've noticed recently that a VPS that I administrate has some strange Apache behaviour. Essentially, any HTTP request hangs for about a second before it is actually served. Output from ab shows ...
0
votes
2answers
380 views

Raid 1 and Latency

I am aware that RAID comes with certain write penalties, etc and that varies at different levels. I am trying to figure out how latency is affected in RAID 1. From my SAN, I can look at the number of ...
1
vote
1answer
457 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
1answer
183 views

How do I calculate the ethernet NIC-to-NIC time to send a MTU packet (1500 bytes)? (OS-excluded) [closed]

I understand it will depend on the speed of the ethernet 10 Mbit to 100 Gbit. Given an ethernet speed, how do I calculate the time spend in the wire from NIC-to-NIC? I am assuming here that the ...
1
vote
1answer
489 views

Exchange Database Write Latency and ActiveSync - correlation?

We have an increasing number of ActiveSync devices connecting to our Exchange 2010 infrastructure (one primary mailbox server with about 920 accounts and counting; plus a cas/hub in the primary site). ...
0
votes
1answer
57 views

Adjust drive latency/lag on Server 2008 server with an array?

Got a 2008 server in production , which currently has "one" disc. (Actually a SAS array, presented as a single disc to the OS.) This "disc" is partitioned into a few sections, with some free space ...
1
vote
0answers
293 views

Network latency in Ubuntu 12.04 LTS

Until recently, my internet connection on my Ubuntu machine was working fine. Then, seemingly out of nowhere, I'm finding severe latency problems. For instance, in my web browser, I'll attempt to ...
0
votes
1answer
395 views

What is a “Latency Outage”? [closed]

I'm one of many customers of Windstream, the only internet provider in my area, and just after having hit the 1-year mark of being a customer, my 10M internet connection became about a 512k ...
-1
votes
1answer
419 views

Ultra Low Latency Linux Distribution or Kernel [closed]

I'd like to know if there are any linux distributions that are focused on low latency networking. The area I'm working in is algorithmic trading, and extremely low latency comms between machines is a ...
0
votes
1answer
370 views

Why do these ipfw delayed pipes have no effect?

I'm on OSX 10.7.5 and am attempting to add some latency to the connection to my personal domain with ipfw, using this article as a guide. Normal latency: > ping -c5 troutwine.us ...
1
vote
2answers
1k views

Should I enable “Intel NIC DMA Channels”?

I have HP DL360p Gen8 646902-xx1 I'm trying to optimize my config for low latency trading. Should I enable "Intel NIC DMA Channels"? Will that help/affect my system? From HP doc: Added a new ROM ...
3
votes
1answer
564 views

Apache Benchmark is slow from public network, magnitudes faster locally. What are some things I do to speed this up?

I am testing my Linode Ubuntu 14 64bit server out, it's the most basic server available from them. I am using Apache Benchmark to test the server, as well as a multithreaded script I wrote in Python, ...
1
vote
0answers
119 views

Website latency and bad tcp packets

I have multiple websites hosted on a Linode VPS and I'm having an issue with one of them: every page that I try to load has about 10 seconds latency. Apache logs are clean and the other websites on ...
0
votes
2answers
761 views

High latency issue for web service call from amazon aws ec2 to local server

We have a legacy web application that is running in our data center on premises located in Houston. We have a developed a new .net 4 based web application in order to provide new features to ...
7
votes
1answer
10k 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. ...
0
votes
1answer
354 views

What exactly is cut-through latency?

This switch datasheet specifies that the "cut-through latency" is 300ns. What exactly does "cut-through latency" mean? Is it: The difference in time between a packet's head entry and that packet's ...
7
votes
3answers
581 views

TCP Window Scaling for Satellite Connections

A satellite connection generally has a RTT around 500ms. Connections generally suffer sub-optimal transfer speeds, in spite of large amounts of bandwidth because TCP acknowledgements take too long to ...
7
votes
2answers
5k views

Data obtained from ping: is it round trip or one way?

I have 2 servers, each in two separate locations. I need to host an application on one, and the database server on the other. From the app server, if I ping the database server, on average I get ...
2
votes
2answers
271 views

Diagnosing network latency issues

I have two servers both with gigabit network cards that were experiencing severe latency issues communicating with one another. The culprit eventually turned out to be that one of the servers was ...
2
votes
1answer
110 views

Performance issue in using Amazon S3 for run-time updates

I have a web application hosted in Amazon EC2 as well as in Rackspace. Users can upload files through this application and also modify them. Those files are stored in local storage in each of these ...
0
votes
3answers
203 views

Is this a latency issue or something else?

I have what I think may be a latency problem. I have a magento installation on a shared host. I know it's best to run magento on a dedicated server but it's early days and it's a good host. When I ...