Performance tuning is the process of modifying a system to improve its efficiency. This is also known as optimizing.

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IRQ not handled by all CPUs

I have a problem about balancing irq. I took irq numbers from /etc/interrupts and assigned each irq to each of 24 CPUs as this tutorial says for i in {143..166};do cat /proc/irq/${i}/smp_affinity; ...
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455 views

KVM Slow performance on XP Guest

The system is very slow to do anything, even browse a local folder, and CPU sits at 100% frequently. Guest is XP 32 bit. Host is Scientific Linux 6.2, Libvirt 0.10, Guest XP OS shows ACPI ...
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1answer
375 views

TCP RWIN, MSS and MTU [closed]

I have been doing some reading into TCP Receive Window (RWIN), Maximum Segment Size (MSS) and Maximum Transmission Unit (MTU). Right off the bat I have some questions and I need a power user's help! ...
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1answer
550 views

Copying cause big iowait

I have dedicated server with 3 HDD. System disk, backup disk (same as system disk) and data disk. When I copy lot of data with cp (say, between backup disk and data disk) load average goes sky high. ...
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101 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 ...
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275 views

Can I tune my Debian KVM server to benefit my Windows guest?

Debian Squeeze KVM server with Win2k8 server guest. The server has 16GBs of RAM and the guest only runs MS SQL, with a 15GB database on it. I am wondering if there is anything I can tune from the ...
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1answer
1k views

NGinx vs Varnish as a reverse proxy in front of Apache w/php [closed]

I am using apache with mod_php to serve content. Mostly the content is fetched form memcache over the network. All of my images, css and js are already on a cdn What are the pros and cons of putting ...
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1k views

Improving TCP performance over a network with small packet loss

I’m trying to improve my TCP throughput over a “high delay network”, with some packet drops, between Linux machines. I set tcp_mem, tcp_wmem and tcp_rmem to “8192 20530752 20530752”. I set rmem_max, ...
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457 views

server benchmarking with apache benchmark

We are testing one of our production server with ab and what we found is apr_socket_recv: Connection timed out (110) Total of 176 requests completed after some time above output.That means the ...
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2answers
639 views

Solaris: Increase TCP's Initial Congestion Window to 10 segments (tcp slow-start)

How can the Initial Congestion Window be increased to 10? It seems it can be done with TCP_INIT_CWND, but I don't know how to do that.
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511 views

Why is MySQL table_cache full but never used

I have been using the tuning-primer.sh script to tune my my.cnf settings. I have most things working well but the part about TABLE CACHE makes no sense: TABLE CACHE Current table_cache value = 900 ...
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3k views

AIX network parameters to close TCP sockets of unplugged devices

We have an AIX box, running what we call in banking "ATM Switch" not the ATM networking switch, but the bank ATM driver. where we have some ATM machines connected to two server processes. The problem ...
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315 views

Tuning Linux TCP for large number of TIME_WAIT

It looks like we have a bunch of tcp connections hanging around on a busy webserver, this is the output from ss -s: Total: 366 (kernel 1037) TCP: 72108 (estab 130, closed 71964, orphaned 0, synrecv ...
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1answer
297 views

4096 and 8192 block size read slower than write? by using lsi 9361-8i RAID10

is it possible that 1024 and 2048 block size read speed is faster than 4096 and 8192 block? I'm using lsi 9361-8i with RAID 10 , with 8 x Kingston E50 250G. result: 1024 = Write: 2,251 MB/s ...
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4answers
32k 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 ...
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4answers
343 views

Trying to scale my dedicated server for high traffic

I have a quad core xeon, 8GB ram, and only 2 x 1TB SATA drives right now. I am trying to figure out how to scale my application to handle as much load and traffic per day as possible. I have an ...
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4answers
2k views

Faster Option: Redirect via PHP to PHP or Apache mod rewrite redirect to PHP?

I want to determine if using Apache's .htaccess mod rewrite is a faster way to redirect to a PHP file, compared to redirecting from one PHP file to another, using the header redirect core function of ...
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4answers
275 views

Exchange 2003 I/O Troubles

We have some internal processes that send email to our Exchange 2003 system (on Win2K3 R2 32bit). Recently they have been intermittently failing with various errors -- boiled down they report "...
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1answer
415 views

PCIe SSD vs SSD vs SAS - which is best for Database?

Since I am going on shipping soon I wonder which generally will mostly boost the database performance ? The bridge question is - which will boost mostly a database which having a lot of random block ...
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4answers
620 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 ...
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3answers
1k views

Increase the performance of sort command on a multi-processor Sun Solaris box

I have a bunch of (rather large i.e. >100MB) comma separated files which needs sorting on 4 processor box with SunOS 5.10 Sort appears to run rather slow (minutes) I am wondering if there is any way ...
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1answer
35 views

Before buying it, how can I tell if a storage array makes certain performance counters available over SNMP?

I've noticed that documentation for SNMP reporting that is built-in to devices (i.e. doesn't need an agent running in an OS) usually doesn't include a list of performance counters that are available ...
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1answer
170 views

Trade reliability for speed in a slow filesystem

On my box running Ubuntu Server 11.10 I have a rather slow soft RAID6 array on four USB sticks (and no other means for persistent storage). I want a faster filesystem on that box. I'm OK if I'd lose ...
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2answers
55 views

how to find the highest IO consumer on a disk? [closed]

Can some one help to find highest IO consumer on each individual disks? i.e Which process consumes the most IO on /dev/sda, the highest IO consumer on /dev/sdb etc.
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1k views

How to turn linux to keep 'cache' high?

We are running a heavy service on Debian. Our service generates lots of file i/o and its performance relies on how well Linux kernel caches files. Our system has 64GB memory. Total file size is 500GB ...
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2answers
5k 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 result....
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102 views

Server configurations for hosting MySQL database

I have a web application which uses a MySQL database hosted on a virtual server. I've been using this server when I started the application and when the database was really small. Now it has grown and ...
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2answers
252 views

How do I increas MySQL Performance by throwing Memory at it?

I have a machine with 1 GB of RAM and have set apache to use STARTSERVER OF 150, and MAXCLIENTS of 150, only half is used so I still have about 500 MB more of spare RAM. I want MySQL to use this up as ...
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1answer
48 views

Current Number of Requests per Second with Apache 2.4

I know how to test the maximum number of requests per second with tools like apache bench and httperf. But is there a way to see the average number of requests per second a live server is currently ...
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2answers
103 views

nginx can't execute many requests

I have a question about nginx tune. I have an application which I want execute 200 times every second. I created bash file and used wget with bqO switch for execute. But it has a problem. When the ...
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1answer
118 views

Seeking advice on performance metrics based on NewRelic dashboard

Some background: I have been given access to our newrelic dashboard for the production servers running a django app on an AWS account, and tasked to come up with some gatling.io (performance testing ...
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2answers
171 views

How to tune a web server and prep it for lots simultaneous visitors?

I have another related question but I'm deviating from it since I'm changing my server to use nginx instead of Apache. Related: Server problems, running out of RAM, really high load average I'm ...
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2answers
1k views

virtual memory optimization on exchange server 2010

Hi I did some Google searching but came up blank I know mycomputer/computer > Properties > advance System settings > Advance[tab] > Settings[Performance] > Advance [Tab] > Change > customsige ...
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1answer
403 views

Linux kernel 3 TCP IP tuning

I found several resources about tuning linux TCP/IP stack parameters in /etc/sysctl.conf for high bandwidth connections, but all refer to kernel 2.6. Does anyone have suggestions about how to tune ...
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2answers
58 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 ...
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1answer
448 views

Trim out useless apache modules

I'm running a shared hosting environment with about 100 sites - I just took a peek at all the modules apache is loading/using, some of these I don't know what they are or do or if they are useful at ...
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1answer
1k views

MySQL hosting: What are the recommended specs and w

I have two specific cases of MySQL hosting. 1) I have a case where I have 2000 plus concurrent users to a single MySQL Database. They are not simple web users, but actual business users who need to ...
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3answers
678 views

Extreme fine tuning MySQL performance wise on a Linux server

I would like to know all of the key points where MySQL can be fine tuned performance wise on a Linux server through my.cnf or through other methods, libraries and tools. Tips and tricks and shady ...
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2answers
184 views

How do I calculate the amount of tuning needed for my server?

I have a server which is running a few discrete Python, Java application which most of the time imports data into a PostGreSQL database. I would like to know from people out there who have experience ...
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2answers
158 views

What to seek/avoid in a hosted server monitoring service?

I'm looking for hosted monitoring solution (CPU, memory, disk, loads, mysql, replication network etc..) for a group of servers on Amazon EC2 /Scalr (app, mysql, load balancer). So far I found http:/...
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2answers
516 views

DB2 insert performance - How to measure

[From stackoverflow] Im trying to find a way to speedup my inserts to a DB2 9.7.1 (ubuntu linux) Im watching vmstat and trying to gather some statistics via the db2 get snapshot commands but im not ...
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1answer
1k views

How to raise max no of file descriptors for daemons running on Debian Jessie?

I'm playing with pgBouncer as a connection pooling system for PostgreSQL. My system is a 12-core with 64GB RAM and 1Gbps network interface running Debian 8.1. Now I want to raise the limit for open ...
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1answer
90 views

Does Apache mod_status give any insight to tuning Apache config?

Does the Apache mod_status output give any insight to tuning Apache prefork config? For example, using Apache's mod_status, I figured out that My server gets 3 requests/sec average, the range is 2-...
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2answers
396 views

increase nginx active connection more than 65535

currently I'm doing setup for nginx to accept C1M, I do in my Virtual BOX with Centos 7.0 and RAM 10G. Here my sysctl.conf configuration. fs.file-max = 9999999 fs.nr_open ...
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2answers
1k views

Linux : SSD performance tweaking queue

I've allready applied well known mountpoint options for ssd, enabled stuff in LVM for ssd optimisation as well. Now i've ran into a possible challenge. Would it be possible to gather information on ...
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1answer
1k views

rmem_max more than rmem_default

I just installed centos 6.3 freshly and noticed the following: [root@localhost user1]# cat /etc/redhat-release CentOS release 6.3 (Final) [root@localhost user1]# [root@localhost user1]# cat /proc/...
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1answer
27 views

One Slower/Larger VS Two Faster/Smaller RAM [closed]

Generally speaking, performance-wise, which one is the best (putting brands aside)? 1x 8GB 1333MHz RAM or 2x 4GB 2400MHz RAM Both DDR3.
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2answers
2k views

LAMP -> CPU usage of Apache processes too high

I have a LAMP system with CentOS 6.4, Apache 2.2.15, MySQL 5.5.32 and PHP 5.3.26 with APC 3.1.10 using a Drupal CMS (https) on a virtual machine with 4 CPUs and 6 GB RAM. My problem is the CPU usage ...
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1answer
279 views

How do I go about finding the bottleneck in a slow web based chat application

I am working on a one-to-one chat application running in production. It uses StropheJS to connect to Ejabberd server over BOSH (using ejabberd's default connection manager). The main problem we are ...
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1answer
1k 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 ...