Tagged Questions

0
votes
0answers
18 views

Mysql Server Performance Hit from Triggers

I have 50 databases on a reasonably spec'd Debian MySQL Server v5.1.63 The size of these database vary from about 3MB -> 7GB each. Each database has a history database and most( but not all) tables ...
0
votes
1answer
29 views

epoll timeout configuration in lighttpd

Is there a configuration option to tune epoll timeout in lighttpd? I'm developing an embedded Linux (2.6) device, with lighttpd 1.4.30. And I'm observing the following issue: even when the system is ...
0
votes
0answers
28 views

Distributed Ehcache Performance vs StandAlone

i am fairly new to Terracotta and EhCache. I am actaully using the Bigmemory Max version (EhCache 2.7.0 ang TSA 4.0.0) to my project. I managed to successfully deploy a Terracotta Cluster with two ...
0
votes
1answer
59 views

Too much I/O generated by postgres stats collector process

I am using XenServer with several virtual machines having local postgres databases. Even when all applications are unused and the databases are idle, each vm causes constant storage network traffic ...
3
votes
0answers
82 views

TCP tunning for ssh port forwarding [closed]

I am using an ubuntu openssh server to allow users to connect to and do dynamic port forwarding. the performance is good until about 100 users are connected. beyond that the performance is dropped too ...
2
votes
2answers
189 views

Changing memory allocator to Jemalloc Centos 6

After reading this blog post about the impact of memory allocators like jemalloc on highly threaded applications, I wanted to test things on a larger scale on some of our cluster of servers. We run ...
0
votes
0answers
55 views

Varnish: Exclude section of page

Is there any way to exclude some webpage parts from cache? For example, I have Recent Additions block on my homepage which gets refreshed after every 15mins. I know there is something like ESI ...
0
votes
0answers
48 views

Apache Settings for a site with multiple concurrent file download [closed]

I have site that allows users to download media file (mp3 mp4). The files range from 10mb to 90mb in size. There are anywhere from 150-300 users signed in and downloading files at one time. Right now ...
0
votes
0answers
142 views

RAID10 (4x SSD) system is super slow for 'dd' and 'find' commands

I have configured two servers each with 32 GByte RAM, 2x Xeon 2.4 GHz, 4x 480 GByte Intel SSD on a LSI MegaRAID SAS 9261-8i controller. They should be identical, however one of them has a very poor ...
2
votes
3answers
192 views

Disk write speed much slower than read speed

I have a VPS server (WiredTree), running CentOS. After experiencing some performance issues I created a simple benchmark for disk read/write speed using the following script: echo Write to disk dd ...
0
votes
6answers
528 views

How to know if my nginx is in good health?

I am running a nginx on EC2 (m1.small) for SSL termination. I am using 2 workers on Ubuntu, with latest nginx (stable), the network throughput is around 2Mbps and system load average is around 2 to ...
-2
votes
1answer
139 views

Which will give more free RAM to linux? [closed]

Trying to avoid some issues so I've been trying to learn vm. in kernel tuning but still a little confused even after googling. The lower background_ratio is the sooner the flushes? the lower ...
1
vote
1answer
200 views

VM Tuning to enhance performance

vm.bdflush = 100 1200 128 512 15 5000 500 1884 2 vm.dirty_ratio = 20 vm.dirty_background_ratio = 10 vm.swappiness = 10 vm.min_free_kbytes = 300000 That means that the MOST dirty data that can be in ...
1
vote
0answers
51 views

Getting the virtual memory address for (major) page faults

On a Linux (Cent OS 5) system, I have a process that accesses a large amount of memory mapped files. The process is generating a large amount of page faults because the aggregated size of the mapped ...
-5
votes
1answer
143 views

CFQ vs Deadline - performance benefits [closed]

Running CPanel and wondering what would be the best for web hosting? deadline is more balanced over CFQ right so would allow for more I/O activities right
3
votes
1answer
418 views

Disabling CPU management

If I add the following processor.max_cstate=0 to the kernel command line for boot up, does that disable all CPU power management and throttling? I also found: ...
-1
votes
1answer
217 views

MySQL runs at >=100% CPU, heavy disk I/O?

Recently my Debian Linux server has been experiencing slow web server response times. I've investigated and it seems that MySQL is the culprit, yet there are no slow queries indicated by the slow ...
6
votes
1answer
104 views

How to prevent IO Load under Linux for Video serving?

I'm currently serving videos of conferences via Nginx on 3 servers; 4 cores, enough memory (no swap used) and RAID-10 with 8 drives per server. Unfortunately iostat -xd 1 gives me 100% on all 3 ...
-7
votes
4answers
5k views

How to achieve 500K requests per second on my webserver? [closed]

I recently gifted myself a new dedicated server and I am trying to squeeze maximum performance out of it, for fun and learning. I am trying to achieve maximum possible requests per second this server ...
0
votes
2answers
55 views

How can I decide up the nature of performed IO?

I am using Linux (3.2.12-3.2.4). I have few "syncer" processes which updates lots and lots SQLite db files in a loop. The database sizes vary from 1 MB to few GB. I have a "searcher" process which ...
1
vote
2answers
263 views

Apache2 on linux - how to track down performance trouble

I am stuck on this topic for a while now: How can I get more details on where response time burns. My Problem is the extreme variance in response times. Sometimes it takes the server 5 or 10 seconds ...
-2
votes
1answer
46 views

Ideal number of server, setup and management [closed]

Have read how large scale sites use different servers for different purpose. Here's what I have in mind: Main app - 1 server Database - 1 server Static files - Cloud hosting (e.g. AWS) Backup - 1 ...
3
votes
2answers
136 views

Measuring I/O Performance Paradox

I'm trying to figure out the correct way to get the 'real world' write performance of my NFS cluster. The NFS export is mount on a XEN hypervisor, and I'm running 'dd' from within a VM. What I ...
2
votes
2answers
175 views

How does one 'qualify a server'

Here is the scenario. Say you are going to be a purchasing great deal of servers, but first are trying out hardware from a vendor, and you need to qualify it. Also, say that the custom software that ...
1
vote
4answers
703 views

Windows Server 2008 R2 poor CPU performance

We have two identical servers with the following specs: 4 sockets containing AMD Opteron 6172 at 2.10 GHz each of which have 12 cores 64 GB RAM One runs Windows Server 2008 R2 Standard, which ...
2
votes
1answer
367 views

ApacheTop like tool for Nginx for measuring hit contents?

Are there ApacheTop like tool for Nginx for measuring hit contents? I want to find out the most popular URL from the web server log (Nginx)
0
votes
2answers
1k views

How can I configure Apache to use more of my CPU?

Apache threads are stacking up on one of my web servers (300-500 simultaneous requests, some taking 3-8s to process!), but CPU usage is very low (~10%). Page load time is slowing way down as a ...
1
vote
1answer
2k views

Memcached Cluster - better to have 3 smaller instances or 2 mediums ones?

Currently I have 2 small servers in an memcached cluster. We are approaching out limits with them and need to grow. What are the pros/cons or going adding another small instance compared with having 2 ...
0
votes
1answer
516 views

Oracle Application Server Performance Monitoring and Tuning (CPU load high)

Oracle Application Server Performance Monitoring and Tuning (CPU load high) i have just hired by a company and my boss give me a performance issue to solve as soon as possible. I don't have any ...
3
votes
2answers
242 views

Tuning MySQL and Linux to reduce maximum response time specifically

We have a MySQL-based application that is very response time sensitive. A MySQL stored procedure needs to respond on average in less than 10 milliseconds and the maximum acceptable response time is 50 ...
4
votes
1answer
420 views

Ubuntu HTTP latency falling into strange quantiles

I have an Ubuntu 10.10 server with plenty of RAM, bandwidth and CPU. I'm seeing a strange, repeatable pattern in the distribution of latencies when serving static files from both Apache and nginx. ...
-1
votes
2answers
116 views

How to perform Server Performance Audit [closed]

Here is the situation. I am the CIO in my work place. The guy on the management team that get to take decision regarding Techy things. I dont do actual development, but we have an IT service provider ...
1
vote
1answer
539 views

Windows Server 2008 File Server Performance Tuning

I am running a Microsoft Windows Server 2008 R2 File Server on our network. It seems that there are many times where accessing the data from the server is really slow, sluggish, or non-responsive. ...
0
votes
3answers
660 views

Increasing Postfix Performance for Outbound Mail

We're trying to optimize a Dell PowerEdge 1850, Dual 3GHz procs, 3072MB RAM, running Postfix 2.8.4 and signing mail with OpenDKIM 2.4.1. iostat -x output is: avg-cpu: %user %nice %system %iowait ...
1
vote
2answers
148 views

SQL performance, how to exactly measure bottlenecks

Yesterday me (programmer) and one of my coworkers from our Hosting department started series of tests to address performance issues with our websites. We are running a server with Windows Server 2008 ...
0
votes
4answers
296 views

Increase application performance on Amazon AWS

I've got a client with an MVC v1 (.NET) application running on a micro instance. On this instance, I've got .NET, IIS 7.5, and MS SQL Server 2008 running to handle the application. The client has ...
1
vote
2answers
421 views

Troubling AB benchmarking result?

I'm a real noob when it comes to sys admin. I'm running an app on an EC2 MicroInstance. Before I launch publicly, I want to make sure that I hit a minimum level of performance. I'm trying out some ...
2
votes
5answers
248 views

Figuring out what's causing a server to slow down

I have a potential client that has a php site that performs fine most of the time. However, every week or so, it will experience lag (slow page loading). I am sure there are a myriad of things that ...
2
votes
5answers
357 views

Does Overclocking Anything Shorten It's Life? [closed]

From a business standpoint... If intel could take a 3.0 GHz CPU, and overclock it to 4.0 GHz - whilst still covering their warranty they would do so. It's absolutely free and makes the chip perceived ...
1
vote
3answers
289 views

Config MySQL to maximum speed and memory

I have a server, 8 cores, 12 GB RAM. This server is only used to run MySQL. So, help me config /etc/my.cnf to maximum speed, memory for MySQL.
3
votes
3answers
944 views

Linux's best filesystem to work with 10000's of files without overloading the system I/O

It is known that certain AMD64 Linuxes are subject of being unresponsive under heavy disk I/O (see Gentoo forums: AMD64 system slow/unresponsive during disk access (Part 2)), unfortunately have such ...
0
votes
0answers
122 views

Where to start fixing an IO Bottle neck in SQL Server?

I recently came across an interesting article that went over using IO statistics to identify the causes of performance issues. After examining my statistics i came to the determination that i had a ...
1
vote
5answers
2k views

VPS hosting is very slow. What's the bottleneck?

I've setup a new VPS hosting, to run a Drupal website but it is extremely slow. It is Ubuntu 10, Apache, php5.2 I've enabled Multi-Processing Module (MPM) module and configured it as follows: ...
3
votes
1answer
226 views

What are some current and relevant benchmark tools for Linux?

I'm specifically interested in benchmarks that approximate or target real in the wild usage scenarios. My main areas of focus are latency, network performance (incoming data over sockets). ...
1
vote
3answers
2k views

How-to manage a MySQL table with over 2 million records

I have an InnoDB table running on MySQL 5.0.45 in CentOS. To make matters worse it is all running in a virtual machine. There are multiple tables that have the probability of exceeding 2 million ...
1
vote
2answers
699 views

Can tail slow down log writing speed on Linux (ext3)?

I'm wondering if tailf can generate blocking I/O which will slow down server responsiveness due to logging. For ex. assuming the following setup: Debian 5.1 linux server (foo) which is managed via ...
2
votes
1answer
83 views

Profiling windows performance

I am used to using profilers for software development. I have had multiple windows pcs which all have slowed down over time, as well as had work PCs become slower. I understand this is probably the ...
3
votes
3answers
332 views

It is possible move a specific file to the beginning of the disk?

It is possible move a specific file to the beginning of the disk? I want to move my virtual machine disk files (virtual disk) to the beginning of the disk to improve disk access performance. I believe ...
3
votes
1answer
547 views

What is the best TCP congest algorithm to use for a mobile device?

Given the multitude of TCP algorithms available now and the rise of Linux based mobile devices, what are ideal algorithm(s) to consider? From reading of the various implementations, Veno and ...
3
votes
2answers
1k views

How can I tell which page is creating a high-CPU-load httpd process?

I have a LAMP server (CentOS-based MediaTemple (DV) Extreme with 2GB RAM) running a customized Wordpress+bbPress combination . At about 30k pageviews per day the server is starting to groan. It ...

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