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

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0answers
22 views

is a VM of 512MB enough to host a PostgreSQL server? [duplicate]

Is a VM of 512MB enough to host a PostgreSQL server? I know it depends on what I will do with it but I am having a hard time to see what a PostgreSQL Server could do on a 512MB machine before it ...
-2
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0answers
27 views

SSD performing slow in my desktop but fast in my laptop [on hold]

I'm having some troubles with the performance of my SSD in my new desktop computer. A couple of months ago I assembled my own desktop with all new and last generation hardware. I include here the ...
0
votes
0answers
21 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
44 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
73 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
37 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
61 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
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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: ...
0
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0answers
38 views

Linux: getting detailed stats for a single HTTP request? [migrated]

I'm writing a script to determine the performance of a service from a client's point of view. To that effect, I need to be able to determine a few stats for each HTTP request like: DNS lookup time ...
-1
votes
1answer
43 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
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0answers
30 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
75 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
73 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
43 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
44 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
81 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
47 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 ...
1
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0answers
29 views

How to troubleshoot an unresponsive server

I'm performance testing my Java based web application (Grails) that is deployed on Tomcat. The server has the below services running on it: Apache HTTPD Apache Tomcat MySql RabbitMQ Even though I ...
0
votes
1answer
96 views

Slow disk performance on Azure Virtual Machine

Okay, so first of all, allow me to say that I'm not an operations person, but a developer. So I'm going into a bit of unknown land here, so please bear with me. I would like to use a Azure Virtual ...
0
votes
1answer
70 views

Slow Upload Speed - CentOS 6

I've been having an issue with my servers upload speed slowing down for the last week. When it first occurred restarting the network service would resolve the slow speeds. The speed would then be okay ...
0
votes
2answers
31 views

SQL Server 2012 which user is using Memory and CPU

For sql server 2012 I am looking for a way to see which active user logins are using how much memory and cpu. I have done a search but it seems there is only a way to see aggregates or how much each ...
0
votes
0answers
14 views

IIS Performance Counters recorded extremely large requests per second value

While I've been monitoring a production IIS server receiving around 1000 - 5000 requests per second almost steadily, I've encountered a few spikes in the performance counter "Requests/sec" and "GET ...
0
votes
0answers
36 views

Slow ext4 read performance on 24-drive hardware RAID6

I have a RAID6 configuration spanned over 24 drives (12x directly attached to the RAID card, 12x via external SAS) running on an ARECA ARC-1880IX-12 (fw V1.51 2012-07-04). The RAID makes up one single ...
0
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0answers
20 views

Why first-time reading file from hdd is slower then next ones? [migrated]

I am measuring my HDD speed with a self-written program. (This is a sort of homework, so I don't need recommendations about existing tools to do that). I do it with the following piece of code: ...
0
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0answers
31 views

Commands taking very long time to execute on ssh

Strangely on few on my linux servers, intermittently, when i try to login through ssh and run commands, they take about 15-30 secs to execute every command. Every commands is executed very slow. But ...
0
votes
0answers
15 views

Dynamics CRM 2013 on premise workflow performance

We are speaking of the time it takes for the workflow state machine to notice that task A is complete, thus satisfying a wait condition in a workflow definition, which then creates task B. User1 ...
0
votes
1answer
62 views

Strange CPU spikes with MySQL

On my server (ubuntu 12.04) mysqld started to show some strange CPU spikes. I've logged some of it as a sample: http://pastebin.com/4MwKUVwL The value after the triple dash '---' is the cpu usage ...
0
votes
1answer
45 views

RAID6 generates quite a IO wait at relatively low TPS

I have a RAID6 array made of 9 SATA3 disks @7200 RPM, 4TB in size. I have them partitioned with Gparted Live as GPT partitions, starting at the first megabyte. I am concerned about the read speed. ...
0
votes
1answer
52 views

Sql Server 2012 Disk I/O Too high

I am running SQL Server 2012 on windows azure VM Windows server 2012. This is a live Database, about 250GB, with high usage. I applied some best practice articles for the temp-db long ago, and also ...
1
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0answers
60 views

Random server load spikes, number of tasks doubles, CPU/Memory consistent

We run a vBulletin forum with 6,000 visitors per day on an SSD VPS with 5GB RAM and 24 CPU Cores. On a typical day we see 30-50 concurrent users at any given moment. On busy mornings, it'll go up to ...
2
votes
0answers
46 views

“Nosy Neighbor” and the CFQ scheduler

I'm trying to understand how does using CFQ affects the "Nosy Neighbor" problem. I'll ask it a bit naively, can a "Nosy Neighbor" even exist when using CFQ? Isn't that CFQ should make sure all ...
8
votes
1answer
426 views

How do I run my PowerShell scripts in parallel without using Jobs?

If I have a script that I need to run against multiple computers, or with multiple different arguments, how can I execute it in parallel, without having to incur the overhead of spawning a new PSJob ...
1
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0answers
41 views

Using Azure for application performance testing

I have some custom system management scripts/applications that I would like to performance test against a large number of systems (10,000+) in an effort to simulate larger-scale enterprise networks. ...
1
vote
1answer
39 views

DFS slowly and using a lot write speed on sender member

I am transferring 400gb of multiple files trough 2 server whit 10gb connection inside one VLAN. When I had 2 servers that were not in production the transfer was very quick using 100% of 1gb ...
0
votes
0answers
33 views

Azure Variable Table v Temp Table

This is a bit long; but I have been working through queries figuring out where a performance issue is coming from. Appreciate you taking the time to read it. I have an application running on a ...
2
votes
1answer
184 views

Will a SSD storage perform like a magnetic for small root volumes in AWS EC2?

I have a t1.micro instance with 8GB of magnetic EBS volume as it's root disk with a LAMP environment on it. I thought that I will upgrade it to t2.micro with 8GB of General Purpose SSD volume. ...
0
votes
1answer
68 views

Why this server is so slow?

I hired a VPS in DigitalOcean, it's hosted in Amsterdam, I'm in Turkey. But server is responding slowly and page is freezing/lagging even at ajax POST-GET request.(there is a basic browser game in ...
3
votes
2answers
246 views

Windows Firewall - blocking IP address ranges en masse - performance considerations?

One of our services is an extranet for the exclusive use of our 200 employees across the UK. We're seeing a huge number of login attempts from China, Russia, Ukraine and Nigeria. I have large lists of ...
0
votes
1answer
40 views

Server is not responding when single connection is blocked

I'm not sure how to properly specify this problem, I'm not really a server expert. I will be glad to provide additional data on demand. I have a PHP web-application running on Ubuntu Server with ...
4
votes
1answer
140 views

HDD is acting up, but S.M.A.R.T says everything is fine

Before I begin, a quick disclaimer. I'm basically a developer forced into a sysadmin role by circumstances, so I apologize in advance if I say something stupid or seem like I don't know what I'm ...
5
votes
1answer
145 views

Why iperf still reports 1Gbps performance when using bonding over two 1Gbps adapters?

As I understand it, bonding brings among other benefits the ability to increase the network speed between two machines in a LAN. Bonding [...] means combining several network interfaces (NICs) to ...
2
votes
1answer
54 views

Linux filesystem page cache - hot or not

How can you tell how much of the filesystem cache is hot (frequently accessed) or not? The use case would be determining when you are approaching the limits of your memory but before you actually hit ...
0
votes
0answers
22 views

Solr Query thread limit

While performing stress tests of our website, it looks like Solr could be bottleneck. It has enough ram, CPU usage is far from 100%, but we still facing problems of waiting for solr response for even ...
2
votes
2answers
76 views

TCP under OpenVPN is very slow (tsg attached)

I have a very weird problem with OpenVPN. Most VPNs work fine, except this one. Here I get very low performance from TCP connections, but the CPU load is low (so, not a CPU issue). OpenVPN is ...
-1
votes
1answer
62 views

Innodb performs IO Operation when idle

I am currently doing some stress testing where I am pushing inserts to the database as fast as I can. The simulation inserts 10000 records per second. After inserting around 200 million records I ...
4
votes
3answers
1k views

Why do servers have SAS instead of SSDs? [closed]

I was wondering why do servers still come with SAS disks instead of SSD disks? I know that SAS are faster than normal hard drives but they are still much slower than SSDs. I think they are more ...
0
votes
1answer
26 views

How do I know website slowness is related to network or my server

I do know that my php pages generate in less than 0.1 seconds. And also I do know that apache max clients has not been ran out. And website is slowness is confirmed by testing from different ...
0
votes
0answers
53 views

Nginx : Images takes too long to load. (1sec to download a 50KB image)

I just switched from Apache to debian 7.6 nginx php-fpm and after running all kind of optimisations it seems that it takes a lot longer than usual to display images : The application is extremely ...
0
votes
1answer
225 views

SCOM alert: The threshold for the Logical Disk\Avg. Disk sec/Transfer performance counter has been exceeded

We are monitoring several Windows Server 2012 R2 VMs running on Hyper-V. Now SCOM (2012 R2 UR2) reports: The threshold for the Logical Disk\Avg. Disk sec/Transfer performance counter has been ...
-1
votes
1answer
30 views

Child process runs in normal priority only. Why? [closed]

I run a scheduled task in Windows Server 2008 R2. I used the technique described here to set its priority to high priority (level 1 of 7). My task runs a process (an EXE file) that creates child ...