Performance tuning is the process of modifying a system to improve its efficiency. This is also known as optimizing.

learn more… | top users | synonyms

3
votes
1answer
834 views

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: ...
2
votes
1answer
49 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 ...
2
votes
1answer
256 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)" ...
2
votes
1answer
385 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
votes
1answer
112 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 ...
2
votes
1answer
231 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 ...
2
votes
1answer
515 views

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 ...
1
vote
1answer
262 views

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 ...
1
vote
1answer
414 views

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 ...
1
vote
1answer
467 views

Copying cause big iowait

I have dedicated server with 3 HDD. System disk, backup disk (same as system disk) and data disk. When I copy lot of data with cp (say, between backup disk and data disk) load average goes sky high. ...
1
vote
1answer
508 views

Why is MySQL table_cache full but never used

I have been using the tuning-primer.sh script to tune my my.cnf settings. I have most things working well but the part about TABLE CACHE makes no sense: TABLE CACHE Current table_cache value = 900 ...
1
vote
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 ...
0
votes
1answer
41 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 ...
0
votes
1answer
470 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 ...
0
votes
1answer
135 views

How to diagnose Nginx bottlenecks at specific number of users

Firstly, I know this is a loaded question, but I hoping that you guys will be able to point me in the right direction.... We've got a number of nginx-fronted web heads which site behind an AWS ELB. ...
0
votes
1answer
222 views

How can i speed up an XWiki installation on debian?

We installed XWiki on Debian. Page load times in default config were about 2 seconds. Tuning the memory parameters according to the XWiki performanve guide brought it down to 1 second. But for a local ...
0
votes
1answer
771 views

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 ...
0
votes
1answer
51 views

TOP processes by system time

I have a system running 2 processes - MySQL and Java I'm seeing 20-30% of the time spent in %system. I've looked around to try and find a way to identify which what the balance of the system time is ...
0
votes
1answer
44 views

How to alleviate high disk reads on server?

We are currently hosting a 3TB library of image galleries on our web server, all searchable by users. With about 400 active users at a certain time on the website, our disk reads are pushing 100% I/O ...
0
votes
1answer
372 views

PHP Settings [pm.max_children, pm.start_servers, pm.min_spare_servers and pm.max_spare_servers]

In the midst of transferring a website from a GoDaddy shared server to an EC2 instance. Handling the traffic, which during peak times on a typical day is around 300 active visitors, has been ...
3
votes
0answers
24 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 ...
3
votes
0answers
90 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 ...
3
votes
0answers
67 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 ...
2
votes
0answers
26 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 ...
2
votes
0answers
31 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 ...
2
votes
0answers
320 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 ...
1
vote
0answers
18 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 ...
1
vote
0answers
30 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 ...
1
vote
0answers
44 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 ...
1
vote
0answers
43 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 ...
1
vote
0answers
129 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 ...
1
vote
0answers
153 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:\ ...
1
vote
0answers
99 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 ...
1
vote
0answers
74 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; ...
1
vote
0answers
96 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 ...
1
vote
0answers
268 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 ...
1
vote
0answers
451 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 ...
0
votes
0answers
8 views

Is it possbile to cache pdf documents on the netscaler?

I have a file server which gets pretty overloaded quickly because it is serving huge pdf documents. I have a netscaler in my enviroment as well, and I was thinking of caching them in some way on the ...
0
votes
0answers
27 views

How to measure file access by process over time?

I would like to take a sampling of data / file access over the course of several hours or days in order to ascertain what processes (with their accompanying files) are consuming the most drive IO in ...
0
votes
0answers
29 views

How to ascertain where to effectively allocate server resources?

I have recently received an upgrade to one of my servers of a 256GB SSD drive (this is in addition to two other primary 1TB drives) and a memory upgrade bringing the server to 64GB from 32GB of RAM. ...
0
votes
0answers
2k 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, ...
0
votes
0answers
366 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 ...
0
votes
0answers
130 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 ...
0
votes
0answers
187 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 ...
0
votes
0answers
284 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 ...
0
votes
0answers
73 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 ...
0
votes
0answers
1k 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. ...
0
votes
0answers
217 views

RAID10 (4x SSD) system is super slow for 'dd' and 'find' commands

I have configured two servers each with 32 GByte RAM, 2x Xeon 2.4 GHz, 4x 480 GByte Intel SSD on a LSI MegaRAID SAS 9261-8i controller. They should be identical, however one of them has a very poor ...
0
votes
0answers
704 views

Ubuntu 12.04 64bit - What would cause high System CPU %sys during high MySQL loads?

128GB RAM, 32cores Xeon RAID 10 SSD. Mysql version is the latest 5.5 for Ubuntu 12.04 . We have a lot of queries - about 1800+ per second. During high MySQL load - 2700+% load on a 32 CPU system - ...
0
votes
0answers
49 views

Job run-time variations on dual socket computer

I'm running scientific software (WRF-NMM, atmosphere simulation, weather prediction). On all computers I used it, job running times of run cycles were consistent. All those machines were one socket, ...