Tagged Questions

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

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-5
votes
0answers
44 views

Slow site, most time spent Blocking/Connecting [on hold]

My site is based on user-submitted content, meaning that users can upload images, etc. The problem is, my website loads extremely slowly on first load (before it caches). For example, here is the ...
1
vote
2answers
26 views

What is the difference between truss -D and truss -E?

I am currently analyzing a command on Solaris that reads from a file and has very low performance. The truss -D commands shows me read system calls taking up to 0.03 seconds, but when I use truss -E, ...
0
votes
0answers
26 views

Good Internet connection, but websites load slowly or not at all and internal web server presents same issue to outside users

Lately, users in my organization have been having problem accessing web pages. The browser status bar will say "Waiting for [site]" or "Downloading...", but pages never load, or only load partially ...
1
vote
1answer
25 views

Ubuntu Server 14.04LTS Swappiness for server with 16GB memory

(don't worry I'm not asking what my setting should be, asking for the theory behind some conflicting advice I've read) My application is one that is lightweight and not under much load, but needs to ...
-2
votes
2answers
60 views

fastest way to transfer small files (faster than scp) [on hold]

Scp is quite slow for transferring individual files. What is the quickest way to do this? The reason I need speed is not because I have a large number of files to transfer. I just want the individual ...
0
votes
1answer
21 views

What is the counter type for Linux's /sys/block/$DEVICE/stat

What are the counter types for /sys/block/$DEVICE/stat? $ cat /sys/block/sda/stat 8323741 42381356 464031898 19207478 1940738 49062039 408122282 79935459 0 22315734 99172579 Specifically, ...
1
vote
1answer
45 views

Website performance sluggish - High CPU and Disk Usage

Over the past couple of days my website's performance has been very sluggish, with queries taking a lot of time to execute. My CPU usage hit around 100% 4 times this week. Here is the output of top at ...
1
vote
0answers
61 views

Is it normal for uploads on ADSL to make the connection unusable (> 4000ms latency)? [migrated]

I have an ongoing saga with my internet connection; where the latency periodically goes through the roof. In most cases, this seems to coincide with something uploading data. I'm not having a lot of ...
0
votes
1answer
25 views

PostgreSQL queries slower than before?

I am using PostgreSQL 9.3 server on my production server. Everything had been working fine for the past couple of months. But since the past week or so, PostgreSQL seems to have becomes very slow with ...
0
votes
1answer
48 views

Measure Dedicated Server Performance

I run an online video streaming site and keep getting more and more dedicated servers. Our business traffic fluctuates on an annual cycle which allows us to scale back our dedicated servers during the ...
0
votes
0answers
31 views

What happens on an SQL Server when a snapshot is taken by VMWare?

Recently I saw in our SQL Server logs that a snapshot could not be taken at the specific time and he retried it later on. During that timespan we had a huge performance problem. Besides the SQL Server ...
0
votes
1answer
66 views

How to solve performance problems with VMware ESXi 5.5 on old Dell PowerEdge 2900 hardware [closed]

I have a couple of old Dell PowerEdge 2900 servers that have come free and I would like to use them to host a mail server cluster. They are a bit old, but have been running workhorses for a while, ...
0
votes
0answers
26 views

Capacity planning of messenger server [duplicate]

This is regarding a messenger server being developed. This will have thousands of users connected and will be able exchange messages. Users will also be able to send messages intended for multiple ...
0
votes
0answers
81 views

Troubleshooting poor Windows Server performance

I have two Windows Servers. One is used as the Gated Check-In build server and the other is planned to replace it. However, the second server demonstrates poor performance despite having superior ...
2
votes
0answers
70 views

Cannot set 1G speed on 10G nic using ethtool

I have a linux server with 10G fibre nics: xyz@xyz48:~$ sudo ethtool p1p1 Settings for p1p1: Supported ports: [ FIBRE ] Supported link modes: 10000baseT/Full Supported pause frame use: ...
0
votes
1answer
45 views

Is it safe and efficient to install HHVM on top Apache server with nginx as reversed proxy?

I've been trying to optimize my VPS for WordPress performance, and today, I decided to take it to a new level: I'm thinking about installing HHVM. Server status: My server runs Apache, and I have ...
0
votes
0answers
15 views

Tuning and configuring Django Application with Apache & Mod Wsgi

We are running Django Application using Apache+mod-wsgi. application is taking too long to load. even a single list view page load takes 6-15 seconds. Can you suggest improvements? Provided are my ...
4
votes
1answer
56 views

Multiple websites on multiple servers - seperate mysql or not

I currently have 2 Debain boxes (VPS - 4Gb memory) and am hosting a variety of websites of different importance, some ore production sites, others are demo/staging/test sites. Approximately 15-20 ...
0
votes
0answers
9 views

Ubuntu Server 14.04 in VirtualBox: disk performance drops with more than 1 CPU [migrated]

I'm running VirtualBox 4.3.18 on OSX 10.9.5 . I install Ubuntu Server 14.04 64bit and performed this basic disk write test: dd if=/dev/zero of=bigfile bs=1024 count=5000000 The result with 14.04 / ...
6
votes
2answers
111 views

Calling sync/fsync slows IO after 30 minutes uptime

After 30 minutes of uptime using Ubuntu 14.04 with an ext4 hybrid SSD I see many processes blocking IO using iotop. The root cause of this slowdown has been traced back to the Unix system call sync. ...
0
votes
0answers
36 views

nginx load balance not increasing request per minute

I have a flask app deployed on a gunicorn server and another server with nginx as reverse proxy. The issue is when I add one or more servers running gunicorn and use nginx to load balance, the ...
0
votes
0answers
56 views

Unexplicable extreme slowness on Dell PowerEdge R320, fixed only by cold reboot

At this customer's site, there are two new Dell PowerEdge R320 servers with the following configuration: A single 6-core CPU 16 GB of RAM 2x500 GB SATA disks in a RAID 1 array The O.S. is Windows ...
2
votes
2answers
66 views

Linux virtual memory tuning to workaround disk I/O issue

I am having a problem with a Linux server that it is writing to much to disk, thus I am having a slow response time due to a big IO wait. I already check smart values for the disks and are OK. This is ...
0
votes
1answer
31 views

Squid proxy performing extremely slow and sometimes doesn't work at all

I recently installed Squid on my desktop machine for testing purposes. I didn't edit the config whatsoever, and just pointed firefox at the proxy to see if it was working. Pages take an insanely long ...
-2
votes
1answer
35 views

Amazon G2 not giving a much better computing performance than my laptop CPU [closed]

I have a Java console application that performs Reed-Solomon error correction on large volumes of data (~700 MB at a time), just to test performance. The application is multithreaded, I can see it ...
0
votes
1answer
34 views

Negative effects of setting nginx workers too high

I've seen numerous posts advising how to set nginx's worker_processes, but very few detailing what happens when this is set too high. I'm about to run some benchmarks, but I'd appreciate advice on ...
-2
votes
1answer
34 views

How to check my site speed? [closed]

im the developer and in charge of a company's Wordpress based site our site started to run a lot slower recently and i am trying to figure it out for two weeks now! My main problem is that every ...
3
votes
0answers
56 views

Odd performance fluctation with php-fpm and nginx

I'm running a load test against a web service. It's a php application running on php-fpm and nginx, with fastcgi. There is a MySQL backend being used for small reads only. Invariably, I'm seeing a ...
-5
votes
1answer
54 views

Distance between DHCP server and remote pc effect performance? [closed]

Hey guys im doing a project where i have to create a WAN network however i was curious whether the distance of the DHCP server will bring down the performance loads if it was held from a different ...
1
vote
1answer
106 views

IPSec Site-to-site VPN speed between Germany and China very poor

we have successfully setup a Site-to-site IPSec VPN connection between our two offices in Germany and China. Below are the characteristics of both sites, VPN and current speeds: Germany VPN Router ...
0
votes
0answers
40 views

Why does chrome show a very long 'blocking' time (sometimes) when loading static files from Jetty 9

I'm seeing some strange behavior from Chrome when loading web resources from a Jetty 9.2.3 instance I'm setting up. In particular, I see some requests returning quickly, while others take a very long ...
0
votes
0answers
54 views

Azure disk performance

I am running on-demand, research D14 instance in Azure South Central US region, with a 4-disk RAID0. Recently the disk performance has become unusably slow, particularly the RAID performance, which is ...
1
vote
1answer
24 views

API and main page as two separated processes

SITUATION I created an REST API for my mobile application and now I want to create a website. API so far is very very simple, just for a couple requests like 'get list of contents', 'update some ...
1
vote
1answer
36 views

VMware VMFS5 Local Storage LUN Sizing

We have a VM ESXi 5.x host using local storage (DAS). It has 2 relatively large Logical Drives in RAID10 (10 HDD x1TB each). So, 2 LUNs of 5TB each. We are considering creating just two ...
3
votes
0answers
40 views

Windows Server 2003 terminal server extreme logon times

For the past week my users have been experiencing extreme logon times. They are generally in the 20 minute range or more. I will lay out my research below to see if anyone may know how to find the ...
0
votes
1answer
93 views

Performance issue HYPER-V : VM shows very high CPU use, but the Physical machine shows very small CPU use

My Hyper-V VM(Server2008R2, SP1) shows very high (almost 100%) CPU use when fully under heavy load (6cores from total physical 8cores, 25Gb RAM from total 32GB) - used as TS, Picture TOP right corner ...
0
votes
0answers
88 views

MongoDB high CPU usage

Running MongoDB 2.4.11 on Ubuntu 14.04.1 LTS In top, this mongod thread is constantly using ~195% CPU: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 24524 mongodb 20 ...
0
votes
1answer
52 views

Website slowing down when many users access simultaneously [closed]

I'm new to web development. I have hosted my website through a free web hosting service providing free subdomain. The free hosting service says that they provide 100 GB bandwidth. I just upload files ...
0
votes
2answers
91 views

Are there any performace gains to using Varnish along php-fpm and nginx? [closed]

PHP-FPM 5.6 and Nginx 1.6.2 would no doubt give maximum performance, at-least speed wise. So, I would like to know if there are any pros/cons to adding varnish cache to gain probably few more speed. I ...
1
vote
0answers
66 views

Appropriate fan speed for a Dell PowerEdge T710

We have a DELL PowerEdge T710 in our office and it is really really noisy, the fans sound like vacuum cleaners! The discussion is whether the server is malconfigured and can be made more silent or if ...
1
vote
3answers
63 views

distributing tables over multiple harddrives

Is there a performance improvement when I distribute database tables over different harddrives? I need to access many different schemas at the same time and I was wondering if adding more harddrives ...
1
vote
0answers
46 views

Why is my server using swap even though there is lots of RAM available? [duplicate]

My server has 24 cores, 16 GB RAM, and 8 SSDs on raid 0 (I think). I've noticed it is now using a low of swap space, even though there is plenty of RAM available. load average: 2.70, 2.54, 2.50 Mem: ...
-1
votes
1answer
50 views

Long Apache Wait times

Thanks for reading my question. I've been having a strange problem with Apache 2.4 on my dedicated Windows Server 2008 machine (8 gigs of RAM, Intel Xeon E3-1220 3.1GHz, 1 gig link). For some reason ...
0
votes
0answers
52 views

Dual core CPUs stall with Docker on Ubuntu Linux

I have seen performance degradation after half an hour to one hour with machines running Celery (Django/Python), or Storm under Docker containers with Ubuntu base on Dual-core CPUs on AWS. I see ...
2
votes
1answer
128 views

iostat - dm-0 device shows much higher latencies than sdX

We are running linux (Centos 5.x) VM's on top of vmware vsphere 5.5. I am monitoring disk latency using iostat, specifically the await column, but I am noticing strange results with the device ...
1
vote
3answers
90 views

Increasing nginx performance past 1k req/s

I am trying to scale an nginx installation to the best of it's ability. I am running one nginx instance with 6 worker_processes (6 cores) and 5 backend servers consisting af a uwsgi setup with 10 ...
0
votes
0answers
52 views

RAID0 : best chunk size for fileserver with average 650KB files

I found out that my server(linux Ubuntu Server 14.04) has probably a to high chunk size for the RAID0, or atleast I think this is an performance issue... The current chunk size is 512K with 4 disk of ...
-3
votes
1answer
56 views

Nginx can't serve more than 40 concurrent users

I'm testing my Nginx web server (configured with CentminMod) with https://www.blitz.io/ and the server returns timeouts when the connected users are about 40. I can't understand why! It's Nginx, not ...
1
vote
0answers
87 views

Server RAID0: one hdd is more %busy then the others?

I'm testing 3 servers with RAID0 with 4 disks. During my test I noticed on all 3 servers that one of the hdd's is more %busy and has much higher averige IO wait (almost 4x higher then the other ...
1
vote
1answer
96 views

Cisco 2901 - IPSec VPN Maxing CPU

We have a Cisco 2901 on the edge of a 100Mbps/100Mbps WAN link which is providing an endpoint for an IPSec VPN to a Juniper SSG 550M. The problem is that we are seeing a max of 'only' 40Mbps over the ...