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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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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 ...
4
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1answer
1k views

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 ...
3
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1answer
698 views

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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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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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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1answer
769 views

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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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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643 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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300 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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100 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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64 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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776 views

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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744 views

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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48 views

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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361 views

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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116 views

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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155 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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155 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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0answers
292 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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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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193 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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239 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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138 views

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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0answers
103 views

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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168 views

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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365 views

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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1k views

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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509 views

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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44 views

Apache Tuning for 512GB RAM

Use Case: API Server Cluster Optimized for JSON Data Submission I have a distributed application sending info to API servers that are slaves of a MySQL 8 master. Applications do full initial sync (~...
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36 views

I/O performance issues with dd “benchmark” on XenServer 7.1 using SLES12-SP3 in HVPVM mode

Why does SLES12-SP3 in HVPVM mode perform that badly compared to the other two? SLES12-SP3 VM inside ESXi 5.5: Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s avgrq-sz avgqu-sz ...
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35 views

Website performance issue while servering a request

we have build a website to provide search in some specific area. For that we have used apache Solr (6.x), HAPROXY (1.6) and apache web server on a single system with CentOS as OS. our expected users ...
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200 views

Ubuntu Server Performance Issues with CockroachDB

I have a cockroachdb node I am playing with. My box has Ubuntu 16.4, 64 GB of RAM, 4 physical cores (Quad Core Intel Xeon 3.3 GHZ). Inserts to this DB are very slow. On a 100000 sample set, average ...
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433 views

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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95 views

Cannot get performance improvement with Haproxy

I have 4 web servers with a ruby web server running, and a server running haproxy. I can get a RPS(request per second) of 300 against one web server using ab. But I can only get a RPS of 340 against ...
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597 views

How to scale my NGINX/Jetty (Spring boot) > 130 requests per scond?

I'm trying to increase the performance of my blog. It's not a standard wordpress/PHP blog, I've built it all my self from scratch using Java. I have a spring boot front end which talks to a ...
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103 views

The used heap memory keeps on increasing on managed servers even though the load test has ended, what could be the reason?

We are having a strange observation while performance testing our web application which is, even after the load test ends, the heap keeps on increasing, what could be the issue? The environment for PT ...
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511 views

MySql High CPU Low memory utilization

I am facing an issue with MySQL server. I am not a primary DB admin, so i might need some assistance in tuning DB. The CPU Utilization shoots up way beyond expectations. It just hovers around 70-90% ...
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777 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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0answers
54 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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81 views

What does the “web transaction” mean in new relic transactions report?

In new relic transaction report breakdown table, I often see an entry called "web transaction" and then there are various DB calls and cache calls. Initially I assumed that it's the time my script is ...
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173 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 ...
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0answers
405 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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0answers
4k views

Apache Worker MPM / PHP-FPM Tuning

I have a VPS running CentOS 6.5, Apache 2.2, PHP-FPM v5.4 and MySQL 5.5. I take advantage of APC and Memcache. The VPS has 8 cores and 8GB RAM. I'm running a medium volume site (15,000 users / day, ...
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909 views

Tunning nginx/php5-fpm : why low memory usage with 800 users?

I did optimize nginx with what I found on the internet My specs are 2 servers load balanced : Intel Xeon E5-1620v2 (4c/8t 3,7 GHz+/3,9 GHz+) 32 Go DDR3 ECC 1600MHz 3x 160Go SSD Intel DC S3500 SATA3 ...
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172 views

What's the bottle neck of server hit 100K request?

The following are two graph of my digital ocean vps instance handle load test request. 10K/s, The only different is the request file size, first is 10K, the second is 20K. Can any one point out the ...
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657 views

tuning apache for low ram low traffic server

I have a low end VPS server with 512megs of ram to host downloads of files (~10-25megs each). what is a good configuration for the following parameters in apache. I expect no more than 10 human users ...
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457 views

OpenSSL performance oddity

I've seen something odd regarding OpenSSL performance. This is the output of 'openssl speed aes-128-cbc' on a physical HP Bl460c Gen8 with dual E5-2680's running RHEL/OEL 6.4x64 and OpenSSL 1.0.0-...
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94 views

Ubuntu backup script kills performance

I run a nightly backup, which takes about 1 hour. During that the performance is bad as hell. It looks pretty much like this: # DB dump ionice -c 3 nice -n 20 mysqldump --skip-lock-tables --user=foo ...
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2k views

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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466 views

choosing a stripe size and allocation size for RAID 5?

I am trying to figure out what stripe size and also allocation size I should use for my RAID 5 setup. we got (6) 2 TB drives in a RAID 5, cost was the biggest factor of all. but I am confused on how ...