Questions tagged [performance-tuning]
Performance tuning is the process of modifying a system to improve its efficiency. This is also known as optimizing.
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How to see actual size of tcp send and receive buffers?
we are on a debian system and are trying to tune the tcp/ip stack to our needs. We all know that you can set the maximum tcp buffer size with some kernel parameters like this:
net.ipv4.tcp_wmem = ...
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How dangerous might it be - and what performance gains may be had - by turning vulnerability mitigations off on non-Internet facing servers?
When a virtual machine Linux host server is non-Internet facing and is used exclusively on a LAN and is using a relatively well tested distribution like Proxmox, how dangerous would it be to turn off ...
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Ansible performance issues on a huge group
So, I have this host group, which consist of 35k VMs.
Aaaand I need to run a playbook over it.
If it does matter - playbook is just a call for community role for installing node_exporter.
But I'm ...
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Interpreting ethtool Coalesce output
Other than tx and rx being the transmit and recieve, can anyone explain what the fields mean in ethtool -c's (Coalescing output) and what effect they have on how coalescing works?
Coalesce parameters ...
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I'm seeing performance problems with postfix accepting mail when the queue is already large, any suggestions?
I use postfix to do final delivery for a mail system I've written. So this postfix installation only accepts mail from me, and bounces. When the postfix queue is empty, it can accept a piece of mail ...
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ESXi very slow with WD reds
I have a small company and we offer tech support to small companies. I've been using the HP Gen8 MicroServer in most of them as a replacement of homebuilt computers for some time.
Sometimes customers ...
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How to find optimum configuration in php.ini on openlitespeed?
I want to increase performance on pagespeed insights, but the problem is I don't know how to use all capacity of hardware on this server ! and I need your help please.
I think litespeed not using all ...
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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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Shingled magnetic recording(SMR) device managed - sequential write performance optimizations
recently (2020-05) many HDD producers were caught silently replacing CMR lines with SMR disks, which brought more exposure to the whole concept.
It seems that most device-managed SMR disks first ...
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Nginx: Optimizing server response time for a HTTP cached website
I have a website with all of the pages served from nginx’s http cache and rarely invalidated or expired.
The average total page download size is around 2 MB
But despite being a static site with no ...
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Tuning Apache KeepAlive Timeout for HTTPS
My website forces HTTPS everywhere and has an average first load time of 3-5 seconds. Thanks to caching, repeat load time is 0.8 seconds.
The SSL negotiation takes 150-300ms on my server, so I want ...
CommunityBot
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Performance for static files (HTML, CSS and JS) of PHP Server - CDN vs NGINX
Without going too much into detail to avoid that this question becomes opinion-based; so talking from a purely technical perspective: When you currently have a PHP-Apache setup, both PHP and Apache ...
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Options for performance improvements on very big Filesystems and high IOWAIT
I have a Ubuntu 16.04 Backup Server with 8x10TB HDD via a SATA 3.0 Backplane. The 8 Harddisks are assembled to a RAID6, an EXT4 Filesystem is in use. This Filesystem stores a huge amount of small ...
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Disadvantages of using ZFS recordsize 16k instead of 128k
I'm using Proxmox on a dedicated server. For production I'm still using ext4, but I decided to start messing around with ZFS.
So I have created two separate ZFS storage pools with diffrent recordsizes:...
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Does the ZFS scrub support parallelization for increased performance, e.g., with a 64-core AMD Threadripper Pro?
I have a 24 drive zpool comprised of 3 RAIDZ1 vdevs running 8 Seagate Exos X18 16TB drives per vdev. This is on a Supermicro MB with a 64-Core (128 thread) AMD Threadripper Pro and 256GB ECC RAM.
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COM+/Desktop Heap errors in IIS affecting sites at random?
We have a Win2K3 server that is hosting 30+ sites. Each site is configured to have its own unique application pool -- so that we can manually recycle specific sites if needed and not kill sessions ...
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Preventing PHP-FPM from crashing under light load
I'm getting a DoS attack on a wordpress site that I host.
173.192.109.118 - - [30/Sep/2015:22:31:36 +0000] "POST /xmlrpc.php HTTP/1.0" 499 0 "-" "Mozilla/4.0 (compatible: MSIE 7.0; Windows NT 6.0)"
...
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Slow apache response time for json api (solved)
I've got an Apache server hosting several json APIs.
This server is running Ubuntu 16.04.4 LTS with Apache and Mysql.
Response times for all API are very good except for one! It takes about 5s to ...
CommunityBot
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switching to worker mpm for apache 2 on ubuntu
How to switch from prefork mpm to worker mpm on ubuntu server?
how to roll back if there is any problem?
root@myserver:~# apache2ctl -l
Compiled in modules:
core.c
mod_log_config.c
mod_logio.c
...
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Why am I getting a Sudden Drop in throughput and sluggishness with no CPU increase
Occasionally, during random parts of the day, I get a 10 minute period of extreme sluggishness where my requests are taking 50-1000 times longer then they normally do. Note: I am on Apache/2.2.16 (...
CommunityBot
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TCP retransmission delays - lost acks
Maybe somebody will be able to help me out with this. I'm trying to find out if there is anything that can be optimized server-side to reduce delays in case of packet loss.
Environment: Windows 2012 ...
CommunityBot
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apache and ajp performance
I have an apache sitting in front of two tomcat app servers(one on the same physical server, the other on a different one) that does time consuming work(0.5 sec to 10sec per request). The apache http ...
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How to tune apache with mpm_event
regarding apache tuning, there are lots of good documents and posts on the web
eg. How To Tune Apache on Ubuntu 14.04 Server
unfortunately almost all of them describe how to tune apache with ...
CommunityBot
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performance monitor in iis 7 to monitor which website is using most resources (asp.net)
I am using Windows Server 2008 R2 and IIS 7.5, and am hosting multiple websites on the same webserver. Is it possible to use Performance Monitor to know on average which website is using the most ...
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Are there any big performance boost when upgrade from Ubuntu 16.04 to 22.04?
If I run the server as MySQL database. (Assume using the same MySQL version).
Are there any big performance boost when upgrade from Ubuntu 16.04 to 22.04?
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What does sunit=0 and swidth=0 mean for XFS file system?
I created an XFS file system using default parameters at the time of creation of a system. Now looking at the output of xfs_info, it show 0 for the values of sunit and swidth. I can't seem to find ...
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Slow SSD performance - IBM X3650 M4 (7915)
I set up a test environment for development purposes. It consists of a IBM X3650 M4 (7915) server with:
2 x Intel Xeon E2690 @ 2.90GHz
96GB 1333MHz ECC RAM
2 x HDD 146GB 15k rpm
6 x SSD 525GB (...
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Is it necessary to ban malicious IP regardless of default firewall setting being deny/reject?
I'm on Linux and using fail2ban as the ban system. So far, it has collected and banned about 150K of malicious IPs, and I'm concerned and wondering if this will gobble a fair amount of resources. As I ...
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Manage Win7 Performance Options via GPO
Our company has many virtual Windows 7 instances. Based on recommendations from VMWare, we want to customize the visual effects to optimize performance. We have found that we can change the following ...
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How to use SMB Multichannel over VPN?
According to this article SMB Multichannel can provide the following capability:
Increased Throughput - The file server can simultaneously transmit additional data by using multiple connections for ...
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How to minimize filesystem overhead
I have an application that uses a lot of space as essentially cache data. The more cache available the better the application performs. We're talking hundreds to thousands of TB. The application can ...
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Tune Linux & Nignx to handle 10k Connections @10Gbps Server
I just got a new 10Gbps server with 8 CPU Cores, 64GB RAM and 1TB NVMe
OS Centos 7.9 kernel 3.10.0-1160.36.2.el7.x86_64 also tried kernel-ml 5.13
SELinux is disabled.
firewalld and irqbalance stopped
...
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MariaDB taking up 100-200% CPU
Server Specs
RAM CPU STORAGE
80 GB 20 Cores 1536 GB SSD
TRANSFER NETWORK IN NETWORK OUT
20 TB 40 Gbps 8000 Mbps
This is the results from show status:
...
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Tuning Linux router and server for better performance / solving single TCP connection slow speed
I have a simplest/common network architecture.
Web server sits behind router on local network. This router does iptables DNAT so port forwarding is achieved to web server.
Therefore, I'm able to ...
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Postgresql performance seems capped, cannot work out why
I'm setting up a new PG13 cluster, on ubuntu 20.04, virtual machine. The performance I'm seeing, via pgbench, is neither good nor bad. What I'm trying to work out is why it is what it is, and not ...
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ZFS Equivalent of lvdisplay snap_percent
I've been using LVM snapshots for backing up MySQL databases.
FLUSH TABLES WITH READ LOCK is issued and then lvcreate --snapshot --size 4G etc. Since the database is live while the snapshot is active ...
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Configure HAProxy on Linux to accept 10K simultaneous connections
I have HAProxy 1.5 running on Ubuntu 14.04 (modified). It accepts connections on http and https ports. Two backend applications process requests using persistent connection.
When I create around 2200 ...
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Samba and luks encrypted disk together: Huge performance loss despite plenty of CPU resources, LUKS and samba alone works as expected
Setup:
SSD encrypted with luks aes-xts 512 bits (256 bits AES key), ext4 filesystem
dd write performance of 138 MB/s, CPU usage 97-100 %
dd if=/dev/zero of=testfile status=progress bs=32M count=128
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Reducing idle CPU usage of Windows Server 2019 Datacenter Core VM
I'm moving a few installations to Windows Server Datacenter Core 2019 running in KVM VMs on Linux hosts.
My first Windows VM has, when it's idle, a bit more than 32000 VM exits per second, half of ...
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How to remove the pause during JBoss 5.1.0 GA boot between ProfileServiceBootstrap and AnnotationCreator?
I've managed to strip down my JBoss profile enough that it boots in 1.5 minutes. I started with the web profile and started pulling out stuff I didn't need. The bulk of my boot time can be seen here:
...
CommunityBot
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How to measure req/sec by analyzing apache logs
I want to measure the justify stress-test result on production env.
How to measure req/sec by analyzing apache logs?
apache2.2
LogFormat "%v:%p %h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{...
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Why do most ulimit recommendations call for setting file descriptor limits to 65535?
In searching for max file descriptor ulimit tuning recommendations, many sites recommend setting a file descriptor size of 65535. In some cases, its 100000, 120000, and even higher. Some of these ...
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How To Change /Lib Directory
Production server / is only 50GB and it's full.
23GB is in /lib | /snapd 11GB /flatpak 7GB
I see the snap store is installing snaps to /var/lib/snapd | I have a second drive /dev/sdb that has 500GB of ...
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How To Increase Postifx Output Volume
All,
I have a new Postfix server that we use to send subscription emails out to customers and send around 200k emails a day. The server is working well, but the queue gets backed up fairly quickly ...
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Does MaxClients determine the number of active users in a site
Keeping all factors constant , assuming my apache server is configured as below , in event mpm
<IfModule mpm_prefork_module>
StartServers 2
MinSpareServers 2
MaxSpareServers 5
MaxClients 200 #
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Apache2 can't handle 200 concurrent requests with 8GB Ram and 4 core cpu
I am load testing a worpress site with loader.io , i am sending 100 concurrent requests per second, running the test in exactly 1 minute. The test fails considerably after 20 seconds or so, nothing ...
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Very slow read/write on software raid1 with nvme device on Ubuntu focal
I have a server with Ubuntu 20.04.1 LTS with NVME ssd devices running on raid1 and the hard drive operates so slow! to open a gzip file to of 500MB to a 3.7GB takes a while.. way more then it should. ...
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How to find out the mySQL query which uses most of the CPU using performance_sc
52893 TID is using 100% CPU in my server
How to find the query corresponds to that TID? For me, this table is empty
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How to do performance tuning of Apache server?
We have an apache server 2.4.X which we are using as a reverse proxy in front of one Java Application . We have enabled Apache status module Apache Status and we are able to see that number of idle ...
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what is the IOPS behavior when partitions of single disk are used in an LVM?
I have an ubuntu 14.04.1 LTS server which have LVM(backed by hardware RAID5) with logical volume and a volume group named "dbstore-lv" and "dbstore-vg" which have sdb1 sdb2 sdb3 created from same sdb ...
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