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Questions tagged [bottleneck]

A bottleneck is the place where transmission is the slowest.

A bottleneck can best be described as the slowest working component in a machine. Suggest you have a computer with 100 super fast CPUs, a bit of memory and an old IDE drive. When we start a process that needs to do parse something from a giant file, our bottleneck will be the I/O. Our CPUs will be able to handle the parsing, but not all of them will be used on max capacity because the I/O will not be able to provide the file fast enough.

This is called a bottleneck. The analogy comes from whenever you try to empty a bottle. There is only so much liquid that can get through the bottle opening (bottleneck).

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How to find the bottleneck while transferring huge files between 2 hosts

We frequently need to transfer huge files (upwards of 50 GB) between two hosts, and the transfer rate never seems to reach the expected throughput for the network. There are several points which could be the bottleneck, but each of their theorical…
Fred
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Why is Postgres sitting 95% idle, with no file I/O?

I have a TileMill/PostGIS stack running on an 8 core Ubuntu 12.04 VM on an OpenStack cloud. It's a rebuild of a very similar system which was running nicely on very similar hardware (same cloud, but different physical hardware, I believe) last week.…
Steve Bennett
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Flush-0:n processes causing massive bottleneck

I have a LAMP cluster that shares files via NFS and occasionally one of them will be stricken for a while when mysterious flush processes start appearing. Can anyone help me? The only way to resolve this is to reboot - killing the processes only…
Tom
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Linux I/O bottleneck with data-movers

I have a 24 core machine with 94.6GiB RAM running Ubuntu server 10.04. The box is experiencing high %iowait, unlike another server we have (4 cores) running the same types and amounts of processes. Both machines are connected to a VNX Raid…
Benjamin
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Find the bottleneck: disk I/O on Windows XP

One of our development boxes has developed a problem wherein performance will occasionally drop through the floor. When this happens, you can hear the hard drive thrashing, but I don't know what's causing it. This happens during periods of high…
Ben Blank
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How to troubleshoot slow performance on AWS EC2/RDS?

We recently moved our web servers from some 10 year old boxes to AWS EC2. Usage of the site is currently higher now (it's our busy season) and the site has become much slower, which is unexpected because our instance sizes are much higher than what…
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Steps to diagnose performance bottlenecks on Mac OS X

If you wanted to track down performance issues on a machine running Mac OS X and find out what was causing slowdowns, which command-line or graphical tools would you use, and how would you use them? I'm interested in advice on the best tools, and…
Dave Cahill
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MySQL high CPU usage on small website

I have a small website hosted on a dedicated server (FreeBSD 9.2, MySQL 5.6.1 and php 5.5.5). The problem is that MySQL eats a lot of cpu resources even if the website have a few visitors. The database is small (the biggest table is about ~12k…
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How to determine bottlenecks on Ubuntu LAMP environment

What kind of tests should I run to determine bottlenecks on my server? I'm trying to optimize so I can maintain heavy load spikes when they occur. I'm running Ubuntu in a LAMP environment.
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Recommended SSD Setup

I'm building a new server which will be running a text search service for our online web services. This service requires fast IO so I am trying to further reduce any potential bottlenecks. I would love to hear some recommendations on SSD's (or…
JohnyD
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Performance monitoring on Linux/Unix

I run a few Windows servers and (Debian and Ubuntu) Linux and AIX servers. I would like to continously monitor performance on these systems in order to easily identify bottlenecks as well as to have an overview of the general activity on the…
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Tangible benefits of keeping web applications and web server separate?

We develop and maintain web applications; and in our current setup; we are using a three-tier system of database server, application server, and web server. So far, so good. The problem we are facing is that while in theory this setup is designed to…
Williham Totland
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Identifying saturated disks on CentOS 8

A quick background; I have a 10Gbit file server with six data SSDs running CentOS 8 and I'm struggling to saturate the line. Everything's fine if I cap bandwidth at 5 or 6Gbps. Here's some charts from Cockpit showing all is well (~850 concurrent…
Vimm
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Disk or Network Bottleneck and Perfmon?

I'm trying to see if we're choking our NAS server with RAID 5 on a PERC RAID card. I've been playing with Perfmon and have been looking at various ways to try narrowing down the performance counting but am hitting things like, for example, finding…
Bart Silverstrim
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Estimate if the network throughput is reached

I have 2 processes communicating over TCP/IP as following: process A sends 20 KB of data to process B and after some calculations process B sends the response (2KB) back to A. When I run both processes in the same computer 100 times in a loop…
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