2
votes
2answers
188 views

Is there anything I can do to decrease waiting time for my static http requests (in chrome's network panel)?

I am running amazon aws ec2 micro instance on Ubuntu 14.04 with apache 2.4.9. The reason for having this instance is just to test and to solve some bugs before rolling up the project. Currently there ...
3
votes
1answer
5k views

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 ...
2
votes
2answers
547 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 ...
1
vote
3answers
484 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 ...
1
vote
1answer
296 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
2answers
663 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 ...
2
votes
1answer
106 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 ...
3
votes
2answers
826 views

LatencyTop on Centos 6.2

What do I need to do to get LatencyTop working on Centos 6.2? Does it involve compiling a debug kernel with some extra flags? Both the man page and the website are very short of information. ...
11
votes
3answers
1k views

Determining a realistic measure of requests per second for a web server

I'm setting up a nginx stack and optimizing the configuration before going live. Running ab to stress test the machine, I was disappointed to see things topping out at 150 requests per second with a ...
0
votes
2answers
1k views

What is the internal latency of a Cisco 3560?

Our trading network is very latency sensitive. We use Arista switches for the latency sensitive parts, and we know that the latency there is 600 ns. However, we have a Cisco 3560 in part of the ...
2
votes
2answers
158 views

Set up server far away from target audience? [closed]

I live in Canada, and I want to move out of online web hosting and host stuff on my own server. The problem is, my website caters to a huge amount of US traffic, about 90 percent of traffic is US. ...
1
vote
3answers
942 views

How to optimize Windows Server 2008 TCP Latency?

I 'm designing a distributed system and I deploy it on 1Gb cluster of Windows Server 2008 R2 But I have issue with the latency, the normal Ping takes 0.270ms and I believe this is too much, since all ...
1
vote
3answers
2k views

What kind of latency numbers are reasonable for a corporate network?

I am a software developer and I sometimes want to work from home but to write code over on a VPN is just tortuously slow. I have tried several different things to try and make it more reasonable. On ...
3
votes
1answer
252 views

different ACK behaviors (slowing down throughput?)

I'm running netio (http://freshmeat.net/projects/netio/) on one machine (opensolaris) and contacting two different Linux machines (both on 2.6.18-128.el5 ), machine A and machine B. Machine A has a ...
0
votes
3answers
444 views

howto measure network bandwidth/perf

we have a corporate LAN of approx 200 nodes behind a firewall and recently upgraded bandwidth of ISP. Now we want to measure the performance / bandwidth (internet as well file copy perf on local ...
3
votes
2answers
430 views

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 ...
1
vote
2answers
1k 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 ...
2
votes
3answers
2k 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
votes
1answer
525 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
votes
4answers
166 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 - ...
2
votes
2answers
361 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 ...
1
vote
5answers
4k 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) ...