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

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0
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1answer
23 views
+50

How to find which db/collection/query triggers disk read?

We're running a MongoDB 3.0 server with multiple users accessing it and we're experiencing very frequent disk reads by mongod process utilizing our SSD drives to 100% During these peaks the page ...
1
vote
1answer
178 views

Huge performance penalty in gbit link with ip forwarding / masquerade through clear VPN tunnel

I have a problem with IP forwarding between my home computer and a remote server (from online.net). My home connection is a 1 Gbit/s FTTH and the remote server has a 2.5 Gbit/s bandwidth. The context ...
2
votes
2answers
53 views

How can SSD write performance be dramatically different on two identical servers?

I am renting two identical physical servers (at Serverloft). These servers come with 2x512 GB SSD disks, and I've set them up with mdadm in a RAID1. The disks are locally installed in the server. The ...
1
vote
2answers
30 views

How to balance elasticsearch (java) on a very powerful machine?

On a 16 core XEON class, 128GB RAM RHEL server I want to deploy elasticsearch. What is preferable performance-wise? Have a huge elasticsearch process to use all resources on the native host? Break ...
0
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0answers
12 views

Gathering Performance Metrics (RAM, CPU, etc) AWS & Azure

We're developing a cross cloud plane performance metric harvester, to collect various performance metrics, but the top 3 being RAM usage, CPU Utilization and Disk Utilization. I know CloudWatch will ...
6
votes
3answers
9k views

Understanding RedHat's recommended tuned profiles

We are going to roll out tuned (and numad) on ~1000 servers, the majority of them being VMware servers either on NetApp or 3Par storage. According to RedHats documentation we should choose the ...
4
votes
0answers
2k views

Use perfmon to monitor a specific ASP.NET webapp across worker process restarts, IIS restarts, etc.?

I have a few perfmon performance counters that I'd like to track for a specific ASP.NET application over an extended period of time, say a week or a month. The trouble is that perfmon counters are ...
1
vote
1answer
1k 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
0answers
8 views

Move htaccess rules to apache configuration files

I'm running a website with Joomla on a dedicated server (Debian), and i've read that moving .htaccess rules to apache2 configuration files may result in a good performance improvement (Apache HTTP ...
0
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0answers
71 views

MongoDB high page faults every 15 minutes, delayed readers

We have a relatively small MongoDB production replicaset. We do about 100 operations per second -- balanced reads and writes. Every 15 minutes or so we see a spike in response time on reads, and in ...
1
vote
1answer
2k views

interpreting IOPS these Bonnie++ and iostat results

I am looking to interpret the IOPS from a few runs of bonnie++ using iostat simultaneously and using the benchmarking from this post: Can I determine IOPS on a disk array using bonnie++? bonnie++ ...
0
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0answers
22 views

We are constantly getting CPU Spikes and site slows down [duplicate]

Our website works fine and fast, then out of nowhere cpu spikes to 100% site becomes really slow and after 10 minutes it is back to normal, this is constantly happening. How would one diagnose this? ...
0
votes
1answer
2k views

Performance Issue Between SQL and IIS on Seperate Machines

First time OP on serverfault, but an avid user of stackoverflow. We have two high-specification boxes, both running Windows Server 2008 R2 Standard. On one we have IIS 7.5, the other SQL Server 2008 ...
14
votes
2answers
9k views

See what files are being written to (like iotop but for files, not processes)

I have a Linux server, and it's doing a lot of disk io. There is one process that is doing most of the disk writes. I found this out with iotop, which shows the processes that are doing disk I/O. Is ...
2
votes
4answers
2k views

Slow write Performance with HP H240 HBA using internal Storage with Raid 5 SSD's

I am having a HP Proliant DL 160 Gen9 Server with a HP H240 Host Bus Adapter. 6x 1 TB Samsung SSD's configured in a raid 5 directly using the internal storage of the machine. After installing a VM on ...
-1
votes
1answer
32 views

mpm_prefork values for 2-4 GB RAM [duplicate]

I have bought new linode (1GB). On this page :https://www.linode.com/docs/websites/lamp/install-lamp-on-ubuntu-16-04 Linode says: Below are the suggested values for a 1GB Linode: ...
4
votes
2answers
53 views

Massive performance degradation on sustained sequential write

I'm in the process of migrating data into LUKS partitions. Now that the operating system drive is running off LUKS, I tried to start migrating the data drives. Then the server stopped responding. ...
4
votes
2answers
1k views

Files served from Apache are slower than other methods

I have a vps with a 1Gb/s line, when running apps on the server I can get (be it not full) reasonable speeds, but when downloading files through apache from this server I never reach close to my line ...
-2
votes
1answer
18 views

Calculate CPU parallel-processing performance [on hold]

I have made a script in C where I do prime number calculation and can specify to perform concurrent calculations on multiple CPUs. Based on the results I have gathered real and user time with 1, 2 and ...
0
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0answers
19 views

RAID 1 disk sequential read/write speed inconsistent

I have an issue with 2 of my servers, and I'm not sure what's going on. The setup is the same for all my servers: C: 2 SSD 512GB in RAID-1 D: 2 SSD 512GB in RAID-1 The servers are DELL's, the ...
1
vote
3answers
59 views

How to improve AWS RDS Performance - Heavy read write updates

After searching and reading as many posts, comments and discussions I could find I did not find one specific to my issue. I have multiple AWS EC2 deployments with a single RDS all in the same ...
1
vote
1answer
73 views

How to identify the cause of 100% CPU usage in Azure App Service?

I have five apps in an Azure App Service Plan, all different copies of the same app for different clients. It's an ASP.NET MVC app with an SQL database. This morning I woke up to slow and ...
1
vote
0answers
9 views

Windows Server Backup Snap-In Initializes/Moves Extremely Slowly

I have an SBS-2011 box. The WSB snap-in consistently takes 10+ minutes to move beyond 'Reading Data'. After the snap-in finally initializes I experience the same behavior when performing a recovery. ...
-2
votes
1answer
40 views

Analyzing server performance [duplicate]

Analyzing server performance Hi we have recently finished work on one ecommerce site which is built on opencart 2.x and site has around 1k products. The site is currently running on VPS server. from ...
0
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0answers
14 views

Servers experience intermittent CPU “sensitivity”

We have a strange intermittent issue with a few servers where their CPU's become more "sensitive" to load. By this I mean that processes that generally run without issue, suddenly take up ...
6
votes
5answers
8k views

How can I replay Apache access logs back at my servers to do real world load testing?

I looked at http://serverfault.com/questions/2107/tools-for-load-testing-http-servers but I couldn't see how to replay my own existing logs in any of those tools. I have a bug that only occurs under ...
0
votes
1answer
590 views

Performance issues with new dedicated server

I have just subscribed to a new dedicated server and am getting worse than expected PHP execution performance. Execution times are twice as high as on my old shared server! I'm definitely not an ...
4
votes
4answers
1k views

RAID 10 - many slow disks vs fewer fast disks

I am looking to buy HDDs for a single server which will be used as development server. The server will use ESXi as hypervisor and will have some but not too many virtual machines (web server, database ...
0
votes
1answer
18 views

Best performance- and backup-strategy with running multiple Webapps and databases on dedicated servers

my company is soon going to move our webservice-hosting to a new hoster and therefore i'm currently planing how everything will run in the future. I have to deploy at least: MsSQL-Database Server ...
7
votes
1answer
112 views

Sluggish performance on NTFS drive with large number of files

I am looking at this setup: Windows Server 2012 1 TB NTFS drive, 4 KB clusters, ~90% full ~10M files stored in 10,000 folders = ~1,000 files/folder Files mostly quite small < 50 KB Virtual drive ...
-2
votes
1answer
112 views

top: sy higher than 70: What is going on here?

From the man page of top: sy: time running kernel processes The sy-value has peaks with values above 50, and then goes down to about 5 again. What could be the root of it? Here are two ...
1
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0answers
21 views

HTTP/2 and SPDY running together in Apache

I have the latest Apache installed and currently support HTTP/2. Can I setup SPDY and run it together with HTTP/2? The goal is to also take advantage of the SPDY for browsers that do not support ...
3
votes
2answers
73 views

Measuring 40Gbe performance

I've connected two hosts via a 40Gbe fibre link and would like to determine a baseline for data transfer between them. I'm seeing relatively low speeds (~620MB/s). It seems that the signalling rate is ...
2
votes
3answers
103 views

SAS / SATA max number of connected disks vs performance

I would like to understand following things: When I have a motherboard with SATA 6gb/s and 8 ports, does it mean that every single port is able to provide 6bg/s speed to disk that is connected over ...
2
votes
0answers
15 views

Forking loads disk

I have a prefork/fork daemon. By atop I see, that master-process often consumes disk: PID TID RDDSK WRDSK WCANCL DSK CMD 16830 - 7264K 48696K 18624K 10% our daemon From strace I see, that it ...
3
votes
3answers
345 views

How to load balance with respect to memory, disk usage, and other attributes

I've found load balancers such as NGINX but those seem to work only by keeping in mind CPU usage and network traffic. How would I load balance with respect to other variables such as the amount of ...
1
vote
1answer
37 views

TcpTimedWaitDelay is missing in Windows Server 2012

Suddenly my server log shows: An operation on a socket could not be performed because the system lacked sufficient buffer space or because a queue was full And I googled and found these links as ...
1
vote
0answers
17 views

rsync: Maximum nice to keep system responsive

Unfortunately a background rsync reduces the responsiveness of a server. I search a way to have maximum niceness for this background task, to keep the server respond fast. My current wrapper ...
5
votes
2answers
485 views

How can I chose a max load threshold depending on the number of available cores?

I have a pipeline that runs some computationally intensive tasks on a Linux machine. The script that launches these checks the current load average and—if it is above a certain threshold— waits until ...
46
votes
8answers
21k views

How much of a performance hit for https vs http for apache?

Roughly how much of a performance hit will https take compared to http for the same page? Suppose I can handle 1000 requests/s for abc.php, how much will it decrease by when accessed through https? I ...
1
vote
0answers
30 views

IIS Performance Issues with Flat Files (html, css, js)

We're running an Windows 2012R2 VM with IIS 8.5 with the purpose of serving out flat files, no ASP.NET or other dynamic content is in use. The server is configured to map 5 sites to the same IP & ...
3
votes
0answers
51 views

Improve SSL Performance with Nginx

We have Nginx in the front of our system and we Proxy to Apache at the back. We use SSL/TLS for our connection. Question: Is Nginx the best option to terminate SSL/TLS connections in terms of ...
6
votes
2answers
2k views

How to achieve multiple NFS/TCP connections to the same server?

I'm trying to maximize the NFS/TCP bandwidth between a Linux client and a single NFS server over a 10Gbps link. Although each NFS mount has its own device (major/minor), everything comes down to a ...
1
vote
1answer
33 views

Performance impact enabling intel vt-x

I have a rather unusual question: What is the performance impact when you enable vt-x and you don't need it? I ask this because all of the new servers I receive have this enabled by default in the ...
0
votes
1answer
26 views

What is the best way to analyze data captured from sar?

I've got some sysstat data that has been captured from servers with SAR, and I'm unsure what is the best way to analyze that data. I've found ksar, but it seems to be quite old and out of date. I'd ...
8
votes
2answers
6k views

Nginx auto minify html output

does anyone know of a way to get nginx (or any other method) to minify html output on the fly? It seems straightforward to me and can shave a few kb off and help speed up the site.
23
votes
5answers
19k views

Process runs slower as a scheduled task than it does interactively

I have a scheduled task which is very CPU- and IO-intensive, and takes about four hours to run (building source code, if you're curious). The task is a Powershell script which spawns various ...
0
votes
1answer
20 views

Improving I/O rates for EBS snapshot backed volumes

I'm working with a system that takes a set of 42 rotating daily EBS snapshots of each of its numerous (40) volumes for disaster recovery purposes. EBS volumes are aggregated into a RAID volume. A set ...
1
vote
1answer
33 views

How can I determine which files have high I/O in Windows?

In trying to reduce the storage bottleneck on a Windows server (2008 R2) I need to find the files that have the highest I/O over a long period of time (aka 'hot' files) so I can move those to SSD ...
15
votes
2answers
29k views

Best Mysql cache settings for 8gb RAM dedicated mysql server using only Innodb (5gb database)

I'm a pretty big noob when it comes to setting up mysql for performance. And honestly I'm not worried about the fine tuning to squeeze every last bit of performance out of mysql, but I do know that ...