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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 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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2answers
1k views

Stand alone single thread optimized server vs vm running on VMWare

I apologize for the length of my post. We recently converted our business system to a product that is licensed by the number of Cores. We purchased the 2 core license and are currently running it on ...
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0answers
173 views

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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2answers
85 views

libvirt: guest performance during backup

Here is a simplified version of my backup script that runs in the host: # shutdown the guest to ensure its filesystem is in a stable state virsh shutdown web --mode=acpi sleep 20s # the real script ...
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1answer
745 views

Zabbix : How to acheive 1s interval with active items?

Is it even possible/recommended ? We are trying to set up few active items configured with a 1 second interval. However those items don't keep up the desired interval, instead we are gathering a ...
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1answer
129 views

Hunting for performance-reducing issues on a high-usage server

I host a server through the Google Compute Engine for various purposes, most notably a Minecraft server, and it receives a lot of traffic and usage. We're talking fairly constant CPU usage at 150%, 50 ...
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0answers
159 views

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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35 views

Which IO read/write characteristic is more important for Virtual machine type 2: 4K or sequential [closed]

IO devices often specify their characteristics in terms of: sequential read/write; 4K read/write; Which characteristic is more important for performance of Virtual machine type 2 (like VirtualBox ...
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1answer
1k views

How to tune Nginx + MySQL + PHP-FPM bottleneck to resolve high server load?

My server, Ubuntu 14.04.4 LTS, is running at high load, currently running a single site with Nginx + Wordpress + W3 Total Cache + Memcached. I'm not sure if mysql is causing the workload issue. Here ...
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1answer
558 views

What does the following C-State output mean?

# cat /proc/acpi/processor/CPU0/power active state: C0 max_cstate: C8 maximum allowed latency: 2000000000 usec states: C1: type[C1] promotion[--] demotion[-...
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1answer
224 views

How to find out the response time for C-state to change to higher mode

How much time does the CPU wait to go to higher mode, let's say from C0 to C1? Or if it can be customized, where can I find the current value? Also, does the the C-State changes in stages like first ...
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813 views

Task Manager shows high kernel time

Foreward: Hardware: dual-socket Intel Xeon, 128gb memory, hardware RAID-1 SSD OS: Windows 2012 R2 Standard w/ Remote Desktop Services The Task Manager for one of our terminal/application servers ...
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1answer
803 views

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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0answers
55 views

Why are httpd processes spending increasing amounts of time in logging state?

I'm running an Apache 2.2 web server. When stress testing I notice that I cannot increase load beyond a certain number of simultaneous connections. The strange thing is that I do not seem to have ...
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1answer
406 views

JBOSS AS 7 monitoring Paramaters

We are using JBOSS AS 7 in standalone mode to run our web application. Our user base is around 1000 users and we have 4 instances of a JBOSS running on 4 RHEL6 machines behind a load balancer. ...
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2answers
811 views

Optimizing storage of 10-20 million files on RAID5 (currently using LVM+XFS)

Although I've browsed some of the questions here, I think every situation is different and maybe requires a totally different solution. What I have now: Linux software RAID5 on 4x4TB enterprise HDD ...
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1answer
71 views

Analyzing server performance [duplicate]

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. For some days we are facing some ...
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1answer
363 views

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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1answer
2k views

How to optimize throughput on a linux NAT/router?

I am trying to use an old Fujitsi RX300S2, with a quad core Intel Xeon CPU @2.80GHz as a Gitabit NAT router, it has a dual gigabit NIC on board over PCI-X. The router will also forward multicast ...
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0answers
183 views

Mongodb, we can't go over 100 insert/sec on 200iops HDD

Thanks in advance for your help, we get a strange behaviour in mongodb. So we have a cluster of 20 shards, each composed of 1 master and 2 slaves. This database has a heavy load of write only. However ...
4
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0answers
665 views

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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2answers
5k views

Mysql innodb_buffer_pool_size in relation to innodb_buffer_pool_instances

I run a virtual server with an Owncloud installation on it. Now Owncloud has the problem that the way it's developed at the moment, each file upload causes a little MySql overhead. So is very ...
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1answer
222 views

Persist statistics data from Postgres' stats_temp_directory on demand

We are investigating I/O load in one of our VMs and possibilities to optimize it and it showed that most of the load is generated by the stats collector of PostgreSQL. It jumps between 3,5 and 6,5 MB/...
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1answer
1k views

Virtualization - Ten 1Gbps links or one 10Gbps link? (Performance)

I have a machine that has several VM's (5) and 3 physical networking cards (with each 2 ports), with a total of six 1Gbps ethernet ports. I have a SPF-capable switch, having a total of 48Gbps ...
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0answers
105 views

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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1answer
895 views

Current Number of Requests per Second with Apache 2.4

I know how to test the maximum number of requests per second with tools like apache bench and httperf. But is there a way to see the average number of requests per second a live server is currently ...
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2answers
4k views

Why is my bare-metal 16x 2.93GHz cores computer performing poorer than a VPS with 4x 2.5GHz cores?

I have a written a piece of multi-threaded software that does a bunch of simulations a day. This is a very CPU-intensive task, and I have been running this program on cloud services, usually on ...
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1answer
1k views

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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0answers
72 views

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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0answers
435 views

Google Cloud Long TTFB

Google Cloud seems to be having much longer TTFB than they specify in their documentation for cloud storage. You can see from this WPT result that it varies from 500 to 700 MS. The documentation here ...
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4answers
11k 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 ...
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0answers
301 views

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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0answers
1k views

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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1answer
1k views

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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2answers
130 views

Performance testing LAMP-Cluster - How to find bottle neck?

I have set up a cluster of 3 nodes running a LAMP-Application with HAProxy doing the load balancing. Now I would like to optimize and load test the system. Therefore I am unsing jmeter-ec2 which ...
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1answer
40 views

Find a load on my Web Server [duplicate]

As requested, I am asking the question here. Is there a way to find a load on my web application server without a load / stress testing? I have deployed my application in the Apache Tomcat server. ...
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1answer
7k views

How to raise max no of file descriptors for daemons running on Debian Jessie?

I'm playing with pgBouncer as a connection pooling system for PostgreSQL. My system is a 12-core with 64GB RAM and 1Gbps network interface running Debian 8.1. Now I want to raise the limit for open ...
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1answer
4k views

How do I tell how close I'm getting to somaxconn?

The sysctl option net.core.somaxconn defaults to 128 (on our systems) but can be raised. What exactly is this limit measuring and capping? How do I find out how close I am to the limit? Context: I ...
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1answer
3k views

Nginx performance when running multiple instances on the same machine

I'm trying to understand the performance impact of having multiple nginx instances (masters) running on the same machine, rather than having them all load into a single instance using different server ...
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2answers
11k views

Does 'tuned' need to keep running?

On my CentOS 7 systems, I use tuned-adm to set a profile appropriate to the environment during configuration, but after that, I never subsequently change that profile. It seems that the tuned system ...
2
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1answer
703 views

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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0answers
308 views

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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0answers
77 views

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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0answers
194 views

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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0answers
244 views

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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2answers
1k views

PHP5-FPM pm.max_children affect RAM or CPU+RAM?

Recently inherited a Nginx+PHP5-FPM server, and I'm learning and trying to optimize PHP5-FPM settings. Server info: 4 CPUs (8 threads) 7.5 GiB RAM PHP5-FPM info: pm.max_children = 5 pm....
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3answers
2k views

Virtual machines and I/O heavy workload, is it ever sane?

I have seen on numerous virtualization services (Azure) and products (vmware,kvm,hyperv) I/O and system stalls under heavy I/O workload. My questions are: Is it ever sane to use a Virtualized ...
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1answer
4k views

How to resolve '[info] server seems busy' from apache server logs?

I've seen this question asked a few times but it hasn't had any real answer; so I've decided to post my resolution. The below info message can be seen in the apache error.log: [info] server seems ...
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1answer
283 views

Percona: What are the implications of changing repl.commit_order?

I'm currently doing some trials of Galera Cluster with Percona 5.6. I've progressed to testing a 2 node cluster on baremetal. With repl.commit_order set to 0 (off) the TPS performance as measured with ...
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2answers
88 views

how to find the highest IO consumer on a disk? [closed]

Can some one help to find highest IO consumer on each individual disks? i.e Which process consumes the most IO on /dev/sda, the highest IO consumer on /dev/sdb etc.