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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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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What is the correct way to track and monitor Exchange DB replication "pressure" over time?
I want to determine if some databases are overloaded or unbalanced, and think that looking at the transaction logs created per database over time would tell me which DB is at risk of missing RPO ...
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Further Performance Tuning on Medium SharePoint Farm?
I figured I would post this here, since it may be related more to the server configuration than the SharePoint configuration or a combination of both? I'm open for ideas to try, or even feedback on ...
elorg
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perf tuning for ESX vmfs3 on RAID
looking for recommendations on ESX4 OS - VMFS version3:
RAID-5 : matching the stripe size with VMFS block size? (64K, 128K etc)
RAID controller options: "adaptive read ahead, write-back" on PERC 6i
...
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What should I set the initial MySQL Values in My.cnf to for Performance?
I am just setting up my new Linux Ubuntu 8.04 LTS server now, and getting ready for launch. My application is a PHP built application using the Zend Framework, and there is a MySQL heavy site (as are ...
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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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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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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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How to ask antivirus software to work slower and hence use less disk access?
It is our policy for our end-user's computers (usually laptops) to have high power CPUs, GPUs, RAMs (no less than 16GB) and HDD space (1TB), but we save money by choosing lower rotation speed of HDD. ...
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DRBD weird speed dips
couple of weeks ago I made a test setup for DRBD on couple of servers. The speed was fixed 90MB/800Mb as per my config for initial sync. Now I have reinstalled the OS (CentOS 7.4) to do final install ...
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Execute ps1 script when CPU threshold is meet
I'm looking for a function similar to Debug Diagnostics Collector.
Where you can setup a performance (or any counter) trigger (eg. above 50% CPU over 50 seconds). Once condition of a trigger are ...
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Apache HTTPD configuration for high load [duplicate]
Good day,
I want to be able to serve at least 7000 (preferably 10k) concurrent requests from my Apache Httpd. I have configured my httpd.conf with MPM worker with the following setup
ServerLimit ...
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Troubleshooting poor disk IO performance
Note that while this question is a little Redis-specific, the main problem is generic: a process takes so much HDD IO write bandwidth that other processes can't write anything.
We've got an Ubuntu VM ...
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How to check for bottlenecks in Windows Server 2008 R2
I recently switched out a 10 year old server for a brand new server in a small office and upgraded from Windows Server 2000 to Windows Server 2008 R2. After the switch was complete and some ...
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InnoDB options crashing mysql start AND mysql tuning
I have an innodb on a Ubuntu 10.10 server running on an ESXi platform. I have dedicated 8 CPUs, 32 Gigs of ram, and files stored in a Raid 5 HP SAN of SAS 10k rpm disks. I'm expecting FAST queries! ...
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Do IIS App Pools using Network Service account share memory?
We're trying to tune our IIS farm, and I'm trying to get my head around how Windows allocates resources in our current setup.
We have a pretty standard layout. We host 30+ ASP/ASP.NET sites on our ...
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Profiling windows performance
I am used to using profilers for software development. I have had multiple windows pcs which all have slowed down over time, as well as had work PCs become slower. I understand this is probably the ...
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SQL Server 2005 standard filegroups / files for performance on SAN
I submitted this to stack overflow (here) but realised it should really be on serverfault. so apologies for the incorrect and duplicate posting:
Ok so I've just been on a SQL Server course and we ...
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Very long (>300s) request processing time on Apache Server serving static content from particular IP's
We are running an Apache 2.2 server for a very large web site. Over the past few months we have been having some users reporting slow response times, while others (including our resources, both on ...
user32326
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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
},
...
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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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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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BTRFS, sector alignment and Advance Format Disks
I want to set up a BTRFS RAID1 setup with two WD Red 4TB disks, which possess 4K sectors. Since I am keen to get it right the first time before copying data to it (yes it will be backed up), my ...
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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 hanging when serving random file on page load
I'm optimising a website, and the problem I'm facing with now is server related. During page load, there are about 40-50 requests sent to server (depending on the page), and in every case, server ...
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Different block sizes for partition and underlying logical disk on HP Raid Controller (Linux)
Following links collected in this thread I started to check blockdev and found the following output indicating different sizes for partition c0d9p1 and the underlying device (c0d9):
[root@machine ~]# ...
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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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Server problems, running out of RAM, really high load average
I desperately need help in figuring out how to troubleshoot this problem I'm having. I run a fairly mission critical web server (Debian 7.5, 512MB RAM, 512MB swap, Apache, MySQL). It runs a couple ...
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Faster Option: Redirect via PHP to PHP or Apache mod rewrite redirect to PHP?
I want to determine if using Apache's .htaccess mod rewrite is a faster way to redirect to a PHP file, compared to redirecting from one PHP file to another, using the header redirect core function of ...
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Optimize Apache for EC2 micro instance
I'm running apache2 on a EC2 micro instance with ~600 mb RAM. The instance was running for almost a year without problems, but in the last weeks it just keeps crashing, because the server reached ...
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VPS hosting is very slow. What's the bottleneck?
I've setup a new VPS hosting, to run a Drupal website but it is extremely slow.
It is Ubuntu 10, Apache, php5.2
I've enabled Multi-Processing Module (MPM) module and configured it as follows:
...
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How-to manage a MySQL table with over 2 million records
I have an InnoDB table running on MySQL 5.0.45 in CentOS. To make matters worse it is all running in a virtual machine. There are multiple tables that have the probability of exceeding 2 million ...
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SQL Server Tuning Resources
I want to learn more about tuning SQL Server instances (2005/2008), does anyone have any good resources they can point me at?
Dave
NB: I'm talking about the hardware/instance configuration side of ...
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Serving a static website with nginx. Response time over 600 milliseconds. What’s wrong?
I serve a wordpress blog with nginx http cached to over 99% of the requests with a cache lifetime of 2 days. Here’s a webpage from the site. The webpages have quite a few images and therefore lazy ...
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Is it possible for Windows clients to carry out external queries through an alternative DNS server directly?
Our Windows domain is far away. DNS performance is affected. Would it be possible for Windows clients to carry out external queries through an alternative DNS server directly? I understand this is not ...
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Visualize overloaded nic in linux (kernel time)?
I have a linux server that keeps getting its NIC overloaded and I need to visualize how and why this is occurring based on connections and CPU utilization. How do I do this?
For example; for me to ...
user101130
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How can I configure Apache to use more of my CPU?
Apache threads are stacking up on one of my web servers (300-500 simultaneous requests, some taking 3-8s to process!), but CPU usage is very low (~10%). Page load time is slowing way down as a result....
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What performance statistics can I use to determine if hyperthreading will improve performance?
There are several questions asking if disabling hyperthreading will improve performance (e.g. like this). The answer (as it is to all performance questions) is of course "profile it on your workload"....
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Interpretation of non-zero vmstat “bi/bo” values
What are useful rule-of-thumbs with regard to interpreting non-zero vmstat "bi/bo" values? When are the values "okay" and when are they an indication of that the system is under heavy stress?
The ...
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How well does Windows 7 Handle High Bandwidth-Delay Product Networks
As WAN bandwidths increase default network settings in older operating systems are less and less able to efficiently use the network.
A description of the problem with high bandwidth-delay product ...
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Network Monitoring and Filtering [closed]
As the IT administrator for my company I have been tasked with deciding what traffic to filter, shape, and othewise monitor on our network. What protocols, applications, and other network traffic do ...
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Is there is any tool/way to find out why packet is getting dropped due to an arp cache full?
My developer hypothesis is packet is getting dropped at arp layer. We increased the default value of neigh.default.gc_thresh3 1024 --> 2048 and now everything looks good. But I want to understand is ...
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VM Tuning to enhance performance
vm.bdflush = 100 1200 128 512 15 5000 500 1884 2
vm.dirty_ratio = 20
vm.dirty_background_ratio = 10
vm.swappiness = 10
vm.min_free_kbytes = 300000
That means that the MOST dirty data that can be in ...
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