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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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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Is RSS (receive side scaling) in Windows considered unstable?
When asking a customer to enable RSS in their data center to improve network performance (very high UDP packets-per-sec rate), I was told that they generally turn it off, because after various ...
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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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Identifying bottleneck with nginx VPS load testing
I'm trying to optimize a Digital Ocean droplet (512mb), testing using loader.io
I'm testing on my homepage, which is HTTPS / PHP. I setup FastCGI page cache, which got me from 100 req/sec to 2,000 ...
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Investigating Citrix app server "slowless"
Currently have a client stating that the 5 users on a 2cpu, 4gb mem app server are experiencing slowness and often, locking up for moments at a clip.
Framework is a VM running in vSphere 5.5 [intel ...
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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 ...
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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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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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NFS performs ways worse than SSHFS, how can I debug?
Situation: zfs server over 10GbE p2p at 192.168.201.1 running omnios, debian client at 192.168.201.2. The nfs performs fairly well on big files but horribly slow on small ones. For instance, cp -r /...
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IIS 7 -- how to track down mysterious network & cpu usage?
I've got a 64-bit Server 2008 (R1) box running IIS. Users were complaining about extremely slow-loading pages. After digging around I found:
After isolating the box so only one user was able to ...
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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:
...
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Tuning Linux TCP for large number of TIME_WAIT
It looks like we have a bunch of tcp connections hanging around on a busy webserver, this is the output from ss -s:
Total: 366 (kernel 1037)
TCP: 72108 (estab 130, closed 71964, orphaned 0, synrecv ...
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2
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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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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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Index rollover latency
I have created an ILM policy as follows,
{
"policy": {
"phases": {
"hot": {
"min_age": "0ms",
"actions": {
"rollover": {
"max_docs": 30
},
...
2
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1
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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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1
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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 ...
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what are the memory impacts of increasing a NIC's ring buffer?
What impact (if any) does NIC ring buffer tuning (e.g. via ethtool -G eth0 …) have on system memory utilization? For example, does increasing the ring buffer consume more RAM? And if so, how much? Or ...
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Perf crashing my RH
We are running perf on a 2.6.32-358.56.1.el6.x86_64 on an 8-core, dual socket machine. We have CPU iso on CPUs 1-31 (all except for 0), and our application is using CPUs 1-31. A few seconds into ...
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Bind9 recursive queries have intermittent very long response times
I'm running BIND 9.8.1-P1 caching server on Ubuntu 12.04 LTS on kernel 3.2.0-86-generic-pae.
I've been banging my head against the wall trying to figure this out for weeks and I just have no idea ...
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Performance issues with cross-drive NTFS junctions
I have the following setup:
Windows 8.1 32-bit
Drive 0: system drive, SSD, NTFS, mounted at C:\
Drive 1: data drive, magnetic HDD, NTFS, mounted at C:\Users\Database User\Documents and Z:\ ...
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famd/gamin timeout issue with courier-imap
I'm running a mail server for about 200 users with courier-imap on Debian 7. This server is running a linux kernel 2.6.38 inside a Xen guest having 2 cpu cores and 2 GB RAM. The server accept ...
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Getting the virtual memory address for (major) page faults
On a Linux (Cent OS 5) system, I have a process that accesses a large amount of memory mapped files. The process is generating a large amount of page faults because the aggregated size of the mapped ...
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server benchmarking with apache benchmark
We are testing one of our production server with ab and what we found is
apr_socket_recv: Connection timed out (110)
Total of 176 requests completed
after some time above output.That means the ...
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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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CPU C-states disabling ruins network performance
With intel_idle.max_cstate=1:
root@debian:~# curl -o /dev/null http://xx.xx.38.35:999/speedtest/1000mb
% Total % Received % Xferd Average Speed Time Time Time Current
...
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How to improve performance of Nginx for high PHP processing load?
I wonder how I could improve the performance of my server?
It is configured with Ubuntu 18.04 (LTS), 4 GB RAM, 100 GB SSD, 2 CPU, with Nginx 1.14.0 and PHP 7.2-fpm to handle running and serving a site ...
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Apache performance tuning for high traffic with MPM Event
I currently manage the following set of servers that serve about 700 web pages:
SERVER 1 (WEB)
Web server: Apache 2.4.29 with MPM Event
PHP 7.2.22
CPU: Intel Xeon CPU E5-2673 v4 @2.30GHz (4 cores) ...
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Possible reasons Distribution of durations is tri-modal
Below is the distribution graph of durations from a single page of an asp.net webforms application. As you can see there is a cluster of response times in the 250ms range, there is a cluster in the ...
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Nginx performance issues with single user reqesting but with large configuration file
I have following configuration used in server block and as the number of locations grew, the performance has degraded substantially even if there is only one request (e.g. https://example.com/loc1/...
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Performance on Pinned CPU cores versus automatically managed?
I have a XenServer 7.5 environment where I'm running a single Windows VM with 16 total vCPU's. My server has dual Xeon E5-2620v4 CPU's with 8cores/16threads each clocked at 2.1GHz nominal and a Max ...
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Apache uses 100% CPU but only part of RAM on heavy load
I am running a Website that gets heavy usage at a particular time. I run apache 2.4 on an EC2 Ubuntu 16.04 server with 4 Core CPU and 16GB of RAM and 2GB Swap. Size of the average apache process is ...
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Low NIC throughtput under Hyper-V
I have a Xeon-based Dell T20 with Quad Intel I350 running Windows Server 2016 Hyper-V with OpenSUSE as Gen2 VM. Both Windows Server and OpenSUSE have dedicated ports on I350, no sharing. SR-IOV is ...
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Tuning a LAMP server
I'm trying to load test a LAMP application that my team developed and deployed on AWS ubuntu 14.04 using jmeter. We are using AWS CDN to serve static files, mysql and apache are on the same host.
...
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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 ...
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How are cluster size, buffer size and packet size related for performance?
I'm creating a server on an embedded system. I have a FAT filesystem on an SD card which contains a file, which should be sent via HTTP to some client over wifi that connects to the system.
At first ...
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Optimize Apache serving as backend behind Nginx
Apache (2.4.x) is a well known server and performance optimization is widely discussed and well documented.
Nevertheless, for those cases where Apache is reverse proxied (behind Nginx or other any ...
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How do you measure IMAP performance?
We have a mail server built on top of a Gluster distributed filesystem. While this has proven to be fairly easy to set up and quite stable, the performance of our webmail has been quite slow. So now I ...
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mod_pagespeed css shown render blocking?
I've already found this topic concerning my problem and figured out Google is about to discuss a fix of the blocking js. However, could somebody please check out my client's site squarecard.de with ...
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How to track down bad performance on an api-server
If my api-server shows bad performance, such as high cpu - can this be blamed on the service or on the server?
If a regular app-server shows bad performance, all I can do is track down the methods ...
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Maximum Network throughput for SWIFT storage
I have a SWIFT cluster deployed as part of Openstack which is currently giving me a max throughput of 95 MBS(Megabytes per second). There are 6 proxy servers and 6 storage nodes with replication ...
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Advice Tuning my server
as many others I Learn many info from you in the past and now I manage to run server independently , now I am new to sql tuning and I been searching around the web a while now and tuning seems to be a ...
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Multipath tcp application level performance measurement
I am working on a project related to Multipath tcp and I want to measure the goodput and the RTT at the application level. I don't want to use a traditional tool(netperf, iperf, ...) and I want to ...
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IRQ not handled by all CPUs
I have a problem about balancing irq. I took irq numbers from /etc/interrupts and assigned each irq to each of 24 CPUs as this tutorial says
for i in {143..166};do cat /proc/irq/${i}/smp_affinity; ...
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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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KVM Slow performance on XP Guest
The system is very slow to do anything, even browse a local folder, and CPU sits at 100% frequently. Guest is XP 32 bit. Host is Scientific Linux 6.2, Libvirt 0.10, Guest XP OS shows ACPI ...
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How to avoid Memory "Hard Fault/sec"
i've a problem on my windows 2008 server x64, and i cannot understand how can i solve it.
i'm looking to Resource Monitor and see about 100 to 200 hard faults/sec. and generally the machine is slow. ...
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Can I tune my Debian KVM server to benefit my Windows guest?
Debian Squeeze KVM server with Win2k8 server guest. The server has 16GBs of RAM and the guest only runs MS SQL, with a 15GB database on it. I am wondering if there is anything I can tune from the ...
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Improving TCP performance over a network with small packet loss
I’m trying to improve my TCP throughput over a “high delay network”, with some packet drops, between Linux machines.
I set tcp_mem, tcp_wmem and tcp_rmem to “8192 20530752 20530752”.
I set rmem_max, ...
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2
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Solaris: Increase TCP's Initial Congestion Window to 10 segments (tcp slow-start)
How can the Initial Congestion Window be increased to 10? It seems it can be done with TCP_INIT_CWND, but I don't know how to do that.