Questions tagged [bottleneck]
A bottleneck is the place where transmission is the slowest.
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questions
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1answer
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Limitations to using many SSDs in computing server [closed]
This is a beginner's question:
We have a powerful computing server for roughly 10 users which will be increasingly used for data processing. In the past the main bottleneck was I/O.
I was wondering ...
0
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1answer
33 views
How can I predict whether or not memory will bottleneck a CPU
My question is general, though I have a specific example. My question is this: How can I predict whether a powerful CPU will be fully exploited in a scenario with memory that is (relatively) low?
My ...
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1answer
86 views
How to determine the bottleneck of a given network
Consider an Access Point with a packet queue that can hold up to 50 packets and a network whose bottleneck is a link with a datarate of 50 Mbit/s.
There are quite a few nodes connecting wirelessly ...
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3answers
233 views
find bottleneck of a slow server centos [duplicate]
I have a virtual machine host running Centos 6. It is serving an android application with apache/php/mysql.
When online users gets high in number , the server responds very slowly. Even ssh ...
0
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1answer
720 views
hardisk or network bottleneck?
Im trying to determine which hardware causing the bottleneck of the server, the server is mainly used for serving video files on a heavy traffic site.
i have dstat output look like below (will get up ...
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1answer
45 views
What constant throughput and linear respone time tells about the system?
What does it mean when throughput in the system is constant and only response time changes (linearly)?
Does it mean that I have to have a bottleneck?
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2answers
407 views
Is Quality of Service my ISP's responsibility? [closed]
One person on my network does a massive download, not caring too much about how long it takes. Someone else on my network doesn't want his incessant video streaming interrupted. My understanding is ...
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1answer
1k views
How to tune Nginx + MySQL + PHP-FPM bottleneck to resolve high server load?
My server, Ubuntu 14.04.4 LTS, is running at high load, currently running a single site with Nginx + Wordpress + W3 Total Cache + Memcached.
I'm not sure if mysql is causing the workload issue.
Here ...
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0answers
401 views
How to find the bottleneck for slow rsync
I want to find the bottleneck for a slow rsync.
I see these parts (on byte flow order):
IO on source
CPU on source
Network
CPU on destination
IO on destination
How can I debug this?
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2answers
296 views
Can a VLAN traffic affect other VLANS?
Consider 2 vlans
VLAN-1
VLAN-2
VLAN-1 gets an abnormally large traffic spike from outside world.
Will this affect the other VLAN and will the applications in VLAN-2 have packet loss and high ...
0
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1answer
475 views
Bottleneck PHP/MySQL server
The server is getting slow on peak hours, and I don't really know how to find out the bottleneck. I can upgrade ram and cpu. Currently 2gb and 2x2.4ghz
Linux CENTOS
Around 60.000 pageviews per day
...
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1answer
39 views
Do routers and networks have have a “max threads” configuration? [closed]
I've been stress testing my application now and I've identified a high average network connection time. This is odd because I haven't gone over the max bandwith at all.
What can this be caused by? ...
4
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1answer
11k views
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 ...
5
votes
1answer
17k views
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 ...
2
votes
2answers
74 views
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 ...
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4answers
562 views
Does using all cores reduce efficiency?
I have a program (well, php script) which does some pretty heavy text searching - it loads a 2mb and 40mb file and searches through them to find where each word that appears in the first is present in ...
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1answer
315 views
Network card capable of capturing a tonne of packets and not dropping them?
Edit:
Our server is trying to capture packets at between 500-600Mb/s, but is dropping packets 'due to kernel'.
Data is being written to SSDs, and isn't bottleneck there.
What things should I look ...
0
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1answer
705 views
How can I find the bottle neck? [duplicate]
I have a EC2 m1.large Ubuntu 13.04 Instance runs PHP 5.5, PHP-FPM and NGINX. Cache is handled by Elastic Cache using Redis and the database connects to a separate m1.large MongoDB server. The content ...
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2answers
4k views
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 ...
2
votes
1answer
94 views
May a low DRAM router be a bottleneck for a LAN?
I need to install a LAN that is a hybrid between a star LAN and a cascade LAN. There are two levels (I mean that the maximum number of link to go from the central switch to the most external switch is ...
6
votes
4answers
19k views
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 ...
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6answers
1k views
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. ...
0
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1answer
211 views
Server hard disk read speed and client download speed, is there a connection? [closed]
Ok so a client's download speed is only as fast as a server's upload speed, and vice versa. Based on the answers to this post:
Does upload speed depend upon download speed of the server?
In other ...
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0answers
125 views
Good Perfmon Counters for Initial Troubleshooting
I increasingly deal with users who complain there "computer is slow" or that "it takes forever to load" on the laptops we provide (fairly standard build of Windows 7 32-bit with Office 2010 and a few ...
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5answers
7k views
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 ...
2
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1answer
591 views
Solaris/UNIX: Does snoop have the potential to slow down network traffic?
This is the way I see it.
A copy of the network activity is written to a buffer, and snoop reads from the buffer. As long as snoop is able to get the data out fast enough (writing directly to a file ...
1
vote
1answer
387 views
Server freeze (Disk I/O possibly)
I have a Windows Server 2008 machine that is resyncing disks after a powerloss. The issue is that the system becomes unresponsive after about 10 minutes. We've checked with resource monitor and found ...
1
vote
1answer
2k views
Mysql hangs up the server. How to avoid this?
Sometimes my website 'goes down' due to Mysql consuming all the resources, but I think it does not stop creating more httpd processes. Is that possible? If I restart apache, these processes disappear ...
2
votes
2answers
7k views
What iowait values are ok?
I am trying to find the bottleneck of a server running a fairly busy php/mysql site. My first culprit was io but iostat shows that on average iowait consumes only %3.60 of cpu time. here is the ...
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1answer
2k views
Diagnosing the slow performance of my NAS?
I recently built a NAS box on top of ubuntu server. I have an average transfer of about 10mb/sec over gigabit wire to my computer. I was hoping you guys could give recommendations on how to pinpoint ...
2
votes
2answers
116 views
web app reaching emailing limits - what is the next step up?
Recently i have been working on a popular web app that currently has around 70k members and a lot of traffic, i migrated the site to a new extra large EC2 instance and it seems to be a massive ...
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2answers
2k views
Should I use nginx exclusively, or have it as a proxy to Tomcat (performance related)?
I've planned to create a website that'll be pretty heavy on dynamic content, and want to know what would be the wisest choice for part of my webstack.
Right now I'm trying to decide whether I should ...
3
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1answer
1k views
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 ...
0
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3answers
432 views
Where to look for the bottleneck when download slows down?
Image downloading from our site slows down every evening. Compared to daytime we get %50 more traffic over the evening. In exact figures, during daytime hours, hourly pageview count is around 20k, ...
5
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2answers
4k views
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?
...
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3answers
1k views
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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3answers
405 views
Identifying the bottleneck
So I've got nginx and php-fpm on a cloud server. Using apache benchmark with these settings:
ab -n 300 -c 5 http://example.com/
So the cloud server (from rackspace) was a 256mb one. I ran htop while ...
1
vote
1answer
485 views
How to Build a High Performance Network Traffic Recorder With no Bottlenecks (20Gbps)
I need to build a server which is capable of capturing 20 Gigabit/second network traffic (2 x 10g network adapters - 99% utilization) and store them on a disk with zero packet-lose. The requirements ...
0
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1answer
826 views
Looking for a bottleneck in MySQL server
I have two Ubuntu servers with very similar, if not identical, configuration: both have 16 cores (4 E5540 Xeons), 16GB RAM, HP Smart Array P212 controllers with 2 HDDs in RAID1. I/O scheduler used is ...
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2answers
153 views
Hypervisor load on local disks
What is the I/O load on the local disk system for the host OS in XenServer? I can't find this info anywhere. As we have a SAN for the VMs themselves, can we get away with cheap controller / SATA disk ...
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vote
3answers
2k views
Very slow harddisk performance
Today I was trying to execute a long-running (but highly optimized) query on a server in our company. I've run the same query on the same data on my home computer (5400rpm harddisk) and it took about ...
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1answer
3k views
Bandwidth bottleneck on VMWare ESX Virtual Machine
I have 2 loadbalanced apache virtual servers that handle a couple thousand requests per minute, and I am trying to diagnose the bottleneck that is slowing them down.
My webservers each have one ...
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4answers
16k views
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 ...
0
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2answers
156 views
mySQL Database Performing Extremely Poor on INSERT, DESTROY, but fine on FIND and UPDATE
I believe I've encountered a database scaling issue. I have a table with nearly a million rows in it now and our rails application appears to be hanging whenever we try to create a new instance. I ...
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2answers
839 views
How to tell whats making this server slow
Hello I have an HP server configured for RAID 1+0 using 2 SATA disks. I'm pretty new to handling servers also.
The server has had the same OS(Windows Server 2003) on it for a while so I'm not sure ...
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1answer
1k views
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 ...
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4answers
797 views
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 ...
0
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2answers
250 views
How do I know when server “runs at speed limit”?
Basically I'd like to know if it's possible to speed up my server or not by using caching like squid, checking for possible errors in configuration, optimizing various server software parameters, etc.
...
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6answers
8k views
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 ...
