Questions about server hardware and software performance, or network performance.

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8
votes
3answers
261 views

Adding CPUs puts MySQL 5.5 (Debian) performance down

I am about to setup a database server (MySQL) in OpenVZ container and I've been wondering how many CPUs I should assign to it. I decided to benchmark it. I compared two OS/MySQL distributions and ...
10
votes
2answers
320 views

Do unused application pools in IIS affect performance?

Due to a major update in our architecture, we now have a few unused application pools under IIS (there are no web sites mapped to them). I understand how it can a good idea to remove them just to ...
-1
votes
4answers
763 views

How to explain to users the difference between Xeon and i7/Consumer CPU [closed]

I know that these 2 CPUs, given the same clock speed are still different due to many different factors, but realized I didn't really have enough knowledge to explain it clearly. I assume caching and ...
5
votes
1answer
707 views

Is it bad practice to run a web application server directly on port 80/443

I am hosting a web app on amazon aws, using an ec2 instance. On that instance i will be running only one application. using glassfish v3.0.1 I do not want to run the app using : ...
3
votes
3answers
9k views

How to create a RAM Drive (RAM Disk) in Windows 2008 R2?

There are lots of tools for creating RAM drives. None of them seem to work for windows 2008 R2. Does anyone know if this is possible and if so how. Does anyone know of a tool that does work? I've ...
0
votes
2answers
105 views

How can I find my peak bandwidth usage over a period of time?

I am about to change Dedicated Server providers. My current provider says the uplink is 500M. The (potential) new host offers by default a 100M uplink and charges an extra $100/Month for a Gigabit ...
0
votes
1answer
81 views

Ignore utm_* values with varnish?

Can I 'ignore' query string variables before pulling matching objects from the cache, but not actually remove them from the URL to the end-user? For example, all the marketing utm_source, ...
-1
votes
1answer
2k views

GlusterFs - high load 90-107% CPU

I try and try and try to performance and fix problem with gluster, i try all. I served on gluster webpages, php files, images etc. I have problem after update from 3.3.0 to 3.3.1. I try 3.4 when i ...
-2
votes
1answer
81 views

Streaming Server Network Performance [duplicate]

I have server Linux based on centos 6.5 final 64bit , ram 128 G.B dual E5-2650 processor Hard disk : 4 SSD Hard disk RAID-5 Network Speed 1/Gbps Bandwidth Speed 500/Mbps up to 3/Gbps My ...
1
vote
4answers
387 views

Heavy production MySQL/Percona Database in openvz container

So I'm currently running a MySQL 5.1 database, with the following specs: Proc: Intel(R) Xeon(R) CPU E5-1620 0 @ 3.60GHz RAM: 64 Go disks: 2x 100 Go SSD (RaidSoft) I'm planning to migrate my ...
3
votes
1answer
7k 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 ...
0
votes
0answers
179 views

On a system with 64GB mem the Linux Buffer run full while copying with dd to dev null and io stops till manual drop_caches

I am running a server with linux software raid 10. It is a dual CPU system with 64GB Ram. 2x16GB dimms related to each of the CPUs. I want to use dd to backup kvm virtual machines and run into a ...
2
votes
2answers
356 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 ...
2
votes
2answers
857 views

Windows Server 2003 r2 vs 2008 r2 - Performance for SQL Server [closed]

First off, I'm not a sys admin, just a programmer frustrated by poor server performance… We’re currently running a VM (I believe the host is Win Server 2008) on a newer E5-2650 CPU, 24 GB RAM, at ...
0
votes
0answers
16 views

How to compare and state performance on virtual server instance?

I want to report performance statistics about an algorithm that runs on a virtual server instance with Ubuntu on it. I measured runtime and maximum memory usage but I want to give a statement about ...
2
votes
2answers
245 views

Azure IO performance

We have a number of Windows Server virtual machines that we use for .NET and Java development and QA. I find Azure attractive for the obvious reasons but mainly for the opportunity to reduce ...
1
vote
2answers
480 views

NFS Over OpenVPN: Top Performance Boosters

I have two VPS's - One is running 2008 Server R2 and the other is a Ubuntu 12.04 installation. I am using the Windows VPS for RD sessions for Quickbooks and a couple other apps and using the Ubuntu ...
0
votes
1answer
2k views

Upgrading a PERC h310 to a PERC H710 mini RAID controller on a Dell R620

I have an ESXi 5.0 Free license host using an internal Datastore (RAID 5, 5 Disk) that was configured with a Dell PERC h310 RAID controller. The disk performance was very poor, so I upgraded to the ...
7
votes
4answers
4k views

Using SSD as disk cache

Is there software for Linux to use an SSD as disk cache? I believe that Sun does something like this with ZFS, though not sure. A quick search provides nothing suitable. The goal would be to put ...
1
vote
4answers
521 views

TCPing reports 20ms latency between Web Farm and DB

We have a IIS web farm sitting in a DMZ connecting to a MSSQL DB(Windows Cluster). After troubleshooting some performance problems we stumbled upon strange network behavior. We wanted to test network ...
1
vote
0answers
47 views

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; ...
3
votes
1answer
170 views

Filesystem performance degraded during RAID rebuilding

So quick question - our RAID6 array is currently rebuilding and there is a VERY noticeable filesystem performance hit (home directories are NFS mounted on the array). I'd sort of expect that, given ...
0
votes
3answers
121 views

Is it possible to use curl to accurately stress test a site that has lots of javascript?

I have a web site that has lots of javascript but simple html. I want to try simple stress tests with curl. Is that possible? If I just curl the site I get HTML. So making tons of curl requests won't ...
4
votes
1answer
225 views

Mail Server Storage Backend: Filesystem VS Database

I am trying to compare mail server software to decide which to use at the ISP where I work. I'm confused mainly about which storage backend is better for such use (again, at an ISP, i.e expected large ...
4
votes
6answers
433 views

When is it time to add more cores to your virtual server? [closed]

I have a Linux (RHEL 5.8) server with Java 7 and Tomcat 7. The performance is poor, and I am pretty sure it's the DB queries that are slow. We have 2 cores right now, and load average never exceeds ...
2
votes
2answers
2k views

What performance degradation to expect with Nginx over raw Gunicorn+Gevent?

I'm trying to get a very high performing webserver setup for handling long-polling, websockets etc. I have a VM running (Rackspace) with 1GB RAM / 4 cores. I've setup a very simple gunicorn 'hello ...
3
votes
1answer
143 views

iozone: 5 concurrent threads random read of 300K blocks does more ops/s than using only one thread, what could be the underlying reason?

The partition is in RAID1 using software RAID. Command line used: iozone -s 190g -r 300k -O -b test_file OPS Mode. Output is in operations per second. ...
0
votes
1answer
210 views

Abnormal CPU usage during Disk Write Operations

I have a decent CentOS 6.5 dedicated host (CentOS 6.5/E3-1230 3.2Ghz Quad Core + HT/16GB/Software Raid 1 SATA II/WD2503ABYX/ext4) with the default CentOS kernel and "elevator=deadline" in grub. I/O ...
0
votes
3answers
139 views

Linux: Get information/stats about storage network

I want to know as much info as possible about the SAN a linux server is connected to. What commands will give me the most comprehensive view? Simply knowing the WWN of LUNS doesn't do much for me. ...
0
votes
2answers
31 views

Distributed LAMP vs DB and Web Server same box

We have a very read heavy semantic web (RDF) application which is RHEL 5/Apache 2.2.3/Tomcat 6/Java 6 on one Server, and MySQL 5.1 on another. Apache and MySQL are backported Red Hat repo stuff, so ...
3
votes
2answers
134 views

Intel Xeon E7-4807 vs Intel Xeon X5690

We replaced our main line of business server with a new one. The old server had dual Xeon X5690s in it (2 generation old chip), the new server has quad Xeon E7-4807s. We expect processor performance ...
1
vote
0answers
268 views

apache performance static file

I have a fairly low-budget VPS (1GB RAM + 2 CPU's) to run a few (5 - 10) different small websites (both static and dynamic). These websites have (very) low traffic (average of 500 unique visits for ...
11
votes
4answers
3k views

Why is 1 of my 24 CPUs Pegged at 100%?

I have an HP ProLiant DL380 G7 system using 2 6-core CPUs, with Hyper-threading enabled, for a total of 24 logical CPUs (as seen by Windows). When running our application, total system CPU ...
0
votes
2answers
125 views

Logging detailed network activity on Windows Server 2008

One of my clients is experiencing internet delays and outages within their small network. They've verified with their cable company that the issue is not related to any cable company outages. The ...
2
votes
2answers
100 views

Guaranteeing Shell Responsiveness on Pegged System

So my system is getting DOS'd, or I've just opened a kind-of-huge file (openstreetmaps planet.osm). The system goes totally unresponsive... so unresponsive that it'll take about 10 minutes to get into ...
2
votes
3answers
1k views

CPU/JVM/JBoss 7 slows down over time

I'm experiencing performance slow down on JBoss 7.1.1 Final. I wrote simple program that demostrates this behavior. I generate an array of 100,000 of random integers and run bubble sort on it. ...
0
votes
0answers
324 views

Optimizing disk performance on KVM VM configuration

I have a KVM host server running Ubuntu 12.04 LTS, bare bones installation with only KVM installed. The server has an 8 Core Intel(R) Xeon(R) CPU E3-1230 V2 @ 3.30GHz CPU with 32GB of RAM and SATA ...
3
votes
3answers
203 views

Can a Hyper-V machine be made slower and/or emulate a slow network connection?

I need to reproduce an issue with a client-server asynchronous communication (a bunch of JavaScript AJAX vs. an OData api), seemingly caused by some race condition in the calculations when the server ...
0
votes
1answer
875 views

openvpn TCP/UDP slow SSH/SMB performance

I have question about strange behavior of my openVPN configuration on Debian lenny. I have 2 server configs (one proto tcp-server based and one proto udp based). ISP bandwidth is 7Mbit/7Mbit. When I ...
1
vote
1answer
78 views

can Iowait cause significant RAM consumption increase

I have a node.js process running continuously on a linux EC2 instance, it extracts data and stores it in mysql. Some reads are also performed on the database. The process can run well during hours or ...
0
votes
0answers
62 views

when and how to appropriately use /proc/sys/vm/drop_caches

You can clear page cache with /proc/sys/vm/drop_caches. Can someone provide a practical explanation of how this works, when as a sysadmin you would want to do this, how to determine if your system ...
74
votes
4answers
12k views

Why is TCP accept() performance so bad under Xen?

The rate at which my server can accept() new incoming TCP connections is really bad under Xen. The same test on bare metal hardware shows 3-5x speed ups. How come this is so bad under Xen? Can you ...
1
vote
1answer
757 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 ...
0
votes
0answers
96 views

Block requests based on hostname

Has anyone used this module in their Nginx setup? If yes, I would like to know about it's performance. How much would it affect the response time etc. https://github.com/flant/nginx-http-rdns The ...
0
votes
1answer
467 views

htcacheclean doesn't seem to be cleaning the cache

I'm running mod_cache with apache 2 on a fairly high traffic'd site. I've set the htcacheclean to run in demon mode every 10 minutes to keep the cache at 4GB. It's currently at 15GB and doesn't seem ...
0
votes
1answer
62 views

size of extent on LVM2

in LVM1 there was a limit of 65k extends. So size of extent had to been chosen carefully between wasted space on partitions (to big extent) and maximal possible size of logical volume (too small ...
2
votes
2answers
199 views

performance tuning vs understanding a memory leak?

I've read just about every blog post and serverfault answer relating to this, but have seen absolutely zero improvements to the server's CPU or Memory usage so I feel like I'm missing something. At ...
0
votes
1answer
74 views

Best way to optimize site speed for a large traffic website? [closed]

I'm currently managing a Website for a client of mine who gets about about 500-1000 visits minimum a day, and this includes Members uploading videos, photos, blog posts and other content. The site ...
1
vote
1answer
429 views

please explain my fio results - is O_SYNC|O_DIRECT misbehaving on linux?

I'm going mad over figuring out what the problem could be with one of our storage boxes. With a simple fio script I'm testing random writes using bs=1M and direct=1. The SSD is a Samsung 840pro ...
0
votes
0answers
136 views

mod_pagespeed own js and css render blocking

My mod_pagespeed gives a lower score because it's own js and css are render blocking. Given that the tool is designed to speed up, not slow down, I don't think this is desired behavior by design. Has ...