Questions tagged [performance]
Questions about server hardware and software performance, or network performance.
3,186
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How fast is decryption by a YubiKey? [closed]
Do YubiKeys decrypt GPG or SSH/SFTP data directly within themselves? If so, would that cause a bottleneck? Do YubiKeys have accelerated AES hardware that does most of the heavy lifting of decryption?
...
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2
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How costly are nginx variables?
nginx FAQ Is there a proper way to use nginx variables to make sections of the configuration shorter, using them as macros for making parts of configuration work as templates? ) saying (bold is mine):
...
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1
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0
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Performance of different DIMM modules setups
I am trying to achieve fastest possible DDR3 DIMM modules setup. I have researched available benchmarks, I was able to came to (reasonably satisfactory) resolution between these pairs
1DPC UDIMM vs ...
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1
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678
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Does graphics card affect the server performance
I was wondering does graphics card actually improve the performance of the server or a dedicated cpu is already enough to do the job. If graphic cards capacity is needed how many does it required?
If ...
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1
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552
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Suspicious ksoftirqd_1 process using high cpu [duplicate]
I run this webserver that serves data to a couple of apps. In the last couple of days I have noticed that some requests take some more time than usual, so I did a top to find out what's running and ...
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0
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2k
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How to increase amount of concurrent connections in apache2?
I am running into traffic issues as apache 2.4.18 maxes out on concurrent connections:
ps auxf | grep apache2 | wc -l
258
As soon as 258 is reached the server is waiting to serve new connections ...
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1
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1
answer
783
views
Intermittent KVM performance issues causing performance glitches
We are currently hosted on a hosting provider that allows us to set up multiple virtual machines using KVM, where each virtual machine runs on it's own physical box (ie: one hypervisor, one VM with ...
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3
votes
2
answers
922
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Performance differences between EXT4 and XFS on kernel 4.15.0-76
OS: Ubuntu 18.04.4 LTS
Kernel version: 4.15.0-76-generic
Storage type: RAID10 (4 x SSD)
Question: is it a bug for this version of kernel? EXT4 run a lot slower when we perform same SQL insert test; ...
- 252
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0
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135
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How to find the bottleneck on a virtual server?
I have purchased a cheap virtual server (running with Ubuntu, with 4 virtual? CPUs and guaranteed 8GB RAM, SSD). I started Tomcat8 with my web application (with -Xmx4096m). The startup time is very, ...
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834
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Wrong link speed; what happens if manually set speed using ethtool fails?
I've got a remote xen server and I noticed that the speed link in autoneg is 100 Full Duplex; all my network is 1000 Full Duplex; do you know any reason for this? Ethtool mentions on both my server ...
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0
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53
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Performance Issue
I'm doing some experiments with my application. My application is in a Docker container and it is programmed to send 4 request every second to a web-server. When I host 30 containers on a single ...
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2
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2k
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Why are concurrent downloads faster
Many download managers like this, this and this support downloading a file over multiple parallel connections, one per thread.
The concept is that each connection will download one part of the file ...
3
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1
answer
3k
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Huge MFT and slow performance
I have a Windows Server 2012 R2 with huge MFT and slow performance when listing file in folder. Filesystem is about 350.000 files but in past many millions file was created and delete with crap Backup ...
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0
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674
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How does avgqu-sz size in iostat output relate to r_await and w_await?
Can someone explain what does avgqu-sz mean in the output of iostat? The manual page states like this.
avgqu-sz:
The average queue length of the requests that were issued to the device.
Can ...
- 333
3
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0
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359
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zfs not using full disk I/O
I have setup zfs on a fresh Ubuntu 20.04. But speed seems awfully slow.
The disks can deliver 140 MB/s if run in parallel:
$ parallel -j0 dd if={} of=/dev/null bs=1M count=1000 ::: /dev/disk/by-id/...
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Pages load only when you restart php-fpm
So here's more context in a GIF
Notice how pages do not load on link clicks, but as soon as you run service php7.2-fpm restart it instantly loads the page and like that with every page.
What is ...
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1
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37
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If you have fetched a subdomain, what lookup related performance implications are there for accessing another subdomain on the same TLD?
Consider this example. My browser visits the following URL:
foo.foobar.com
The page on the domain creates an iframe for
bar.foobar.com
Both domains are hosted in AWS Route53 as aliased A records =>...
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2
votes
1
answer
685
views
DELL PowerEdge R740xd - NUMA - memory performance
I have two physical database servers (both Windows Server 2016):
test server (5 years old):
DELL PowerEdge R730xd, 1x Intel(R) Xeon(R) CPU E5-2637 v4 @ 3.50GHz (4C/8T), 192 GB RAM (12x 16GB PC4-...
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1
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654
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How do I know if SSD is the bottleneck in Linux?
I have a database server which uses a Samsung 840 pro disk. The load is constantly higher than usual, even if there is not much activity on the website. So I suspect the disk has worn out. But how can ...
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0
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778
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Monitoring SLA/SLO/SLI using Prometheus
I have done much research about monitoring SLI metrics with Prometheus. I have found only how to monitor a cluster using Kubernetes. I'm hoping to find a response here for simple monitoring.
I also ...
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1
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285
views
Is my server drive on SATA2 or SATA3 based on this output?
smartctl output:
# smartctl -a /dev/sda | grep SATA
SATA Version is: SATA 3.1, 6.0 Gb/s (current: 3.0 Gb/s)
dmesg output (empty):
# dmesg | grep SATA
hdparm output:
# hdparm -I /dev/sda | grep ...
user555159
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1k
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VPS is slow despite low memory and cpu usages
recently the website hosted on VPS becomes very hard to reach at times, and I am trying to figure out why. I noticed the following things:
CPU and memory usages are very low (always <15% if we sum ...
2
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0
answers
133
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Index rollover latency
I have created an ILM policy as follows,
{
"policy": {
"phases": {
"hot": {
"min_age": "0ms",
"actions": {
"rollover": {
"max_docs": 30
},
...
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4
votes
1
answer
2k
views
Slow RAID performance for Samsung EVO's
So I've been suspecting performance bottlenecks on a Samsung EVO 850 RAID1 for sometime, but honestly been too lazy to look into it. Now I was starting a new home project, involving a Vmware ESXi host ...
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1
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1
answer
11k
views
IIS Number of threads worker process for ASP.NET application
TL;DR; Give the worker process more threads!
Background
We have an ASP.NET application that expose a Web API where one of the "endpoints/methods" makes a set of queries to external system (SQL, AD ...
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1
vote
2
answers
6k
views
RAID 50 vs RAID 10 for performance?
I have a server with 6 SSD's and a raid controller card that supports both RAID 10 and RAID 50 the plan is to use this as our Build server. It will be pulling in NPM Packages and many small code files,...
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1
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349
views
My.ini issues with server trying to host multiple connections
I am hosting a game server on a dedicated host. all my ini information and screenshots along with my task manager
please assist with this issue
______
# Example MySQL config file for small systems.
#...
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0
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1
answer
60
views
When should we use containerized application on Linux
I would like to create a Linux server but I'm stuck on one question:
How to know when I should use Docker or Lxc for a given application instead of installing it natively ?
For example, on my server ...
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1
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1
answer
1k
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Strange Azure VM performance Issues
We have 5 VMs on Azure for a customer. All VMs have been running smoothly.
Now since Monday the VM of one of the users is losing performance every day at 4 PM UTC+1 (+-1h). When we have these ...
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0
answers
48
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AWS Performance Insight Huge Load from "Other" SQL
Engine: MySQL 5.7.26
Looking at my AWS Performance Insight metrics, I noticed that most of my Database load consumes the query marked "Other" Can I check what is hidden under this label?
Screenshot:
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Buy new VPS just for Mysql or upgrade current one and keep the whole stack on the same server [duplicate]
This is not a question about capacity planning, its about mysql performance over local network vs on the same virtual machine (where it needs to share cpu with other processes)
I have a wordpress+...
1
vote
1
answer
639
views
Bottleneck identification using iostat, vmstat, mpstat
I am doing some Apache and MySQL performance tests, then upgrading a single component and running tests again to see where the bottlenecks are. I have a local used server warehouse (Tams in Lindon UT) ...
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1
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155
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jdb2 spike every hour for few seconds
I get IO hang up every hour on the exact same time on my Ubuntu 18.04 server.
iotop indicate that jbd2 spike to araong 30% around this time.
The hangup last only few seconds.
I started noticing this ...
0
votes
1
answer
10k
views
Ceph hardware sizing calculator
I would like to calculate the Hardware sizing for a ceph cluster. There are so few references to the sizing, that I try to get these details here in the community.
E.g. what shall i have depending on
...
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608
views
Virtual machine disk I/O latency spikes
Since past few days I have strange I/O spikes in one virtual machine.
Its
2.6.32-504.el6.x86_64 #1 SMP Tue Sep 16 01:56:35 EDT 2014 x86_64 x86_64 x86_64 GNU/Linux
Red Hat Enterprise Linux Server ...
0
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1
answer
2k
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Nearly 100% disk utilization after upgrading to debian 10 without any reason
We recently upgraded our servers to debian 10. The setup is completely the same as with debian9 beside of course some new software packages.
We are running the default kernel:
$ uname -a
Linux ...
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1
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1
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471
views
SQLite WAL concurrent write performance on UNIX systems
I have two setups: one runs on windows 10 (ntfs partition), the other on debian (ext4 partition). The R source code is the same. The main process starts 8 child-processes (P-SOCKS) -- on 8 vcores -- ...
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2
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VM Performance on Different Hardware [closed]
I just bought a new server to act as a Hyper-V host for our current VMs. The hardware specs are better than our existing server (faster CPU speed, fast disk IO, etc) and I expect to see our VMs ...
0
votes
1
answer
34
views
is there something like the stem-and-leaf plot for timeseries?
When wanting to quickly take a look at the distribution of a sequence of values, the stem-and-leaf plot is an incredibly simple, yet powerful tool. It takes a few minutes to teach the computer to draw ...
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0
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217
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nginx slower than apache2
I migrate my nextcloud-instance from apache2 to nginx and I hoped that is faster than apache, but it isn't. We've around 30requests/s on this page.
With apache2 I've 160req/s and with nginx I got ...
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1
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901
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Where is my bottleneck: RAM, CPU or disk?
I have a 32 core, 64 thread, 128GB RAM system with internal SSD.
I'm running 64 data mining/simulation jobs in parallel that each load 1GB from disk and run for about 5-10 minutes .
I want to know ...
0
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0
answers
910
views
will a shutdown of a worker process for pool a affect pool b
I have two pools running on the same server.
I noticed one of them is configured to a 20 min idle timeout, and the other is 180 mins.
I can see this message in event viewer:
"A worker process with ...
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2
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2
answers
1k
views
DoS attack? Vast majority of apache workers in 'Reading Request' mode, site down last night, slow now
So I think my server might be suffering a Denial of Service attack.
We got notified by pingdom (website monitoring) that our website was unavailable starting around 3AM. Early today we started ...
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1
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12k
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What's the difference between 10k/15k SAS HDDs and SATA SSDs?
What is the rule of thumb in performance characteristics and differences between 10k / 15k revolutions per minute (RPM) Serial Attached Storage (SAS) hard disc drives (HDDs), versus Serial ATA (SATA) ...
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173
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does running wordpress as subdomain on iis website reduce performance
So it seems the usual googling won't suffice here for this question.
Lets break it down.
I have a main IIS website running on https://www.mymainsite.com
I have a wordpress website running as a ...
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1
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915
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One process takes all server resources (iowait?)
I have multiple processes running simultaneously on the same box under CentOS 7 (each one on behalf of the separate Linux user).
I use Zabbix for monitoring.
Sometimes the following pattern ...
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1
vote
1
answer
394
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FreeNAS + LAGG Slow Transfer?
I built a new file server that should be way overbuilt for its purpose. It has 2 Intel(R) Xeon(R) CPU E5-2660 v3, with 128GB of ram and it is running LCAP through an Intel X540T2 network card to a ...
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1
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126
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Writes throttled to 500KB/s?
My laptop, running Debian testing, has recently been terribly sluggish at operations involving writing to the disk.
I have no idea where the problem comes from and would love some help tracking this ...
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1
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233
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Google Cloud Configuration CPUs
I need to configure a machine on Google Cloud Platform (Brazil/Sao Paulo) to run a biometric service and my software provider requested a machine with the following specification:
"2 x Intel® ...
google-cloud-platform
0
votes
2
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946
views
Slow initial connection to database (php / mssql)
Our webserver and database server are on a local network and the webserver uses an IP address to connect to the database.
$con = new \PDO('sqlsrv:Server=10.200.2.1\sql2017;Database=dbname, $user, $...
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