Questions tagged [tuning]

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how do I tune for one-day-a-year traffic [duplicate]

I run a site as a service for the statewide high school swimming community. I do this for love of the sport, so I can't spend a ridiculous sum on hosting, etc. Nor do I need to - except for one day a ...
Eddie Rowe's user avatar
2 votes
0 answers
102 views

find out NUMA locality of process RAM

I am doing an application benchmark with multiple instances of the same application. I found out that pinning their processes (with sched_setaffinity under Linux, with TaskManager under Windows) to ...
Thorsten Staerk's user avatar
1 vote
1 answer
6k views

How to tune MySQL server when big peak of usage is expected

I'm having pretty big issues trying to tune my MySQL server. I was expecting a lot of people on my website after buying a tv ads between 5pm and 6pm, I have more or less 300 persons at the time on the ...
Julqas's user avatar
  • 121
6 votes
1 answer
476 views

Red Hat Linux tuning for a single application with a few TCP clients [closed]

I know Linux is built for multi-user / concurrent-process, but at the corporate level, many of them are used for single (but big) applications to support an internal service, of which serving only ...
steveoreo's user avatar
1 vote
2 answers
339 views

Beyond 1Gb upload on a single linux server

I have a high hit nginx web server on CentOS that provides static large content. when the number concurrent connection are low, server could easily provide up to 4Gb of traffic , but when the number ...
anthonio mackay's user avatar
2 votes
1 answer
5k views

Postfix seems too aggressive while sending newsletters

I'm having a problem sending newsletters to certain domains/servers, like yahoo or minor network providers. It's like I'm spamming their servers with connections and they tell me to stop after a short ...
SteffenNielsen's user avatar
1 vote
0 answers
127 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; ...
ibrahim's user avatar
  • 431
2 votes
3 answers
816 views

freebsd 7.2 kern.threads.max_threads_per_proc doesn't change after reboot

I have some multithread apps on my server machine based on FreeBSD 7.2, so because of this I need to increase kern.threads.max_threads_per_proc to 4000 (default value is 1500). I changed it using "...
Valeriy Maslov's user avatar
0 votes
1 answer
678 views

mongodb : Can create new thread on FreeBSD?

We experienced some strange thing in our mongodb gridfs platform. The platform actually is a bi Xeon E5 (bi quad core) with 128GB of memory, running on freebsd 9 with a zfs pool dedicated for mongodb. ...
Jean-Dominique BAYLAC's user avatar
1 vote
4 answers
2k views

FATAL: Error inserting acpi_cpufreq

Trying to see how to force CPU to run at higher freq on a HP ProLiant system with SLES 11 SP2. /# modprobe -vv acpi-cpufreq insmod /lib/modules/3.0.13-0.27-default/kernel/drivers/cpufreq/acpi-cpufreq....
Billy K's user avatar
  • 121
0 votes
2 answers
461 views

Why is G-Wan performance so low on Opteron?

I am testing G-Wan 4.3.14 on CentOS 6 with the 2.6.32 Linux kernel using an Opteron 6234 6 module / 12 core processor. Running a simple weighttp test I get: weighttp -k -n 1000000 -t 6 -c 1000 ...
Ersun Warncke's user avatar
1 vote
1 answer
265 views

Tune web server based on stats by munin

At our company, we have set up a munin node to gather data about our web server every five minutes. These datas are presented in a graph, and we're wondering if there is anything to gain from tuning ...
DavidS's user avatar
  • 171
3 votes
3 answers
7k views

NGINX + PHP-FPM + MYSQL - High CPU, Low RAM

All of a sudden our server started to act really weird, extremely high CPU usage and low RAM usage. I've never seen this before and I'm not sure what to do. I feel like if I could get the system to ...
Lew Ayotte's user avatar
26 votes
3 answers
85k views

What value of thread_cache_size should I use?

I'm using Asp.Net together with MySQL. In the .Net connection string, I have set Max Pool Size to 150. If I run the following I get these values: SHOW GLOBAL STATUS LIKE 'max_used_connections'; ...
Martin's user avatar
  • 379
3 votes
2 answers
4k views

How can I see if apache is overloaded and dropping or not accepting connections?

Basically I just want to see if apache is handling a current level of high traffic or if I need to tune it to handle more connections. (I have found plenty of information on the actual tuning, so no ...
cat pants's user avatar
  • 2,283
30 votes
5 answers
37k views

Need to increase nginx throughput to an upstream unix socket -- linux kernel tuning?

I am running an nginx server that acts as a proxy to an upstream unix socket, like this: upstream app_server { server unix:/tmp/app.sock fail_timeout=0; } server { listen ###.###.###....
Ben Lee's user avatar
  • 666
4 votes
3 answers
3k views

Apache performance issue, after "1000 total children" Apache no longer responds to HTTP requests. Not MaxClients issue?

Hoping someone can point me in the right direction as I've spent the last week trying to figure out where the "issue" is but haven't been able to, tried posting to the Apache users mailing lists but ...
Jerome's user avatar
  • 41
3 votes
1 answer
4k views

MySQL com_select?

I'm looking to tune my query cache a bit. According to 7.6.3.4. Query Cache Status and Maintenance in the manual: The Com_select value is given by this formula: Qcache_inserts + Qcache_not_cached ...
symcbean's user avatar
  • 22.4k
1 vote
2 answers
1k views

Best network tuning variables for a Linux proxy

What are the best settings to tune so that Linux can handle a very large amount of TCP connections such as would be seen by a proxy server or a webserver? I'm using Centos6 and squid and am seeing a ...
smarthall's user avatar
  • 138
41 votes
3 answers
117k views

MySQL lowering wait_timeout value to lower number of open connections

I run a rather busy site, and during peek hours I see over 10.000 open connections to my database server on my webserver when a run a netstat command. 99% of the connections are in the TIME_WAIT state....
Mr.Boon's user avatar
  • 1,481
6 votes
3 answers
5k views

Picking the right innodb_buffer_pool_size

I have a 24GB machine running MySQL (only InnoDB tables). My innodb data set is 11.5GB big, and i have set my innodb_buffer_pool_size to 14GB to allow some growth. So the entire innodb data set is ...
Mr.Boon's user avatar
  • 1,481
4 votes
2 answers
18k views

Exhausting Linux machine TCP socket limit (~70k)?

I am the founder of torservers.net, a non-profit that runs Tor exit nodes. We have a number of machines on Gbit connectivity and multiple IPs, and we seem to be hitting a limit of open TCP sockets ...
mo.'s user avatar
  • 78
3 votes
3 answers
7k views

Apache tuning with very high-load LAMP server

I have a LAMP server that can be serving ~400 requests per second at times, the server configuration is: CPU: Intel Quad Core Xeon X3430 (4 x 2.40 GHz, 8MB Cache) RAM: 16 GB REG ECC DDR3 HD: 500 GB ...
Roy's user avatar
  • 31
4 votes
3 answers
7k views

Assigning Processes to CPU Cores

I have access to a CentOS 6 web server (a PHP/MySQL forum) running Apache 2.2.15 and MySQL 5.1.52. This box has dual oct-core Xeons. What I find looking over the CPU graphs is that the first two ...
Baldrick's user avatar
  • 4,242
2 votes
2 answers
3k views

Postfix tuning for high amount

I have do some benchmarks with postfix, where we send out 6 KB HTML Mails. We followed all tuning instructions published by Postfix and used Ramdisk for the queue. We were not able to send above 50 ...
Nenad's user avatar
  • 375
0 votes
2 answers
641 views

Tuning Apache memory usage

I've been working on on getting my webserver in check and I'm running into some issues. First of all, using top I've noticed that Apache is using a lot of memory, no surprise really, but 130-150M per ...
Pooch's user avatar
  • 161
21 votes
4 answers
3k views

Why would a heavily disk intensive application run faster on a SAN than on a Physical Disk?

Why would a heavily disk intensive application run faster on a SAN than on a Physical Disk? I would have expected the Physical disk to be slightly faster but in fact the process ran 100 times faster ...
Stuart Woodward's user avatar
1 vote
1 answer
2k views

fine tuning of my.cnf for InnoDB tables fails with setting of: `innodb_log_file_size=256`

I read some fine tuning recommendations on the mysqlperfomanceblog and tryed to adapt them. I added to my.cnf: innodb_buffer_pool_size = 1000M innodb_log_file_size = 256M After ...
Aufwind's user avatar
  • 113
-1 votes
1 answer
322 views

Linux script to check settings and recommend tuning changes? [closed]

I'm searching for a script to run on our linux server and recommend various tuning changes we might consider making, as well as their suggested values for consideration. Any ideas if something like ...
Will Ashworth's user avatar
2 votes
2 answers
174 views

MySQL query times for tuning are different every time

I am tuning SQL query time for my slow query but every time I get different times so I can't evaluate my optimize solution. For example, I run query select * from abc where abc.status in (x,y,z) and ...
Yadun's user avatar
  • 39
2 votes
1 answer
2k views

RHEL - tcp_delack_min sysctl parameter missing on realtime kernels

I'm looking to modify the tcp_delack_min sysctl tunable on several RHEL/CentOS systems. It should be located at /proc/sys/net/ipv4/tcp_delack_min. I'm finding that it is missing in recent kernels. ...
ewwhite's user avatar
  • 198k
4 votes
1 answer
782 views

Behaviour of solaris tcp stack with relatively high RTT and bursty traffic

I have an application that is distributing data from New York to Tokyo over TCP running Solaris 10. Mean throughput is < 1Mbps, peak throughput can reach 20-30Mbps for seconds at a time though ...
Matt's user avatar
  • 141
2 votes
2 answers
678 views

Linux Disk tuning help

I have a Software RAID1 disk that is randomly experiencing very slow read times. hdparm -t /dev/md0 /dev/md0: Timing buffered disk reads: 2 MB in 12.43 seconds = 164.80 kB/sec It appears to be ...
John P's user avatar
  • 1,689
0 votes
1 answer
216 views

Configuring apache to run in minimal memory

I have a micro instance of Ec2 with Django connected to apache via wsgi. Whenever I hit the server httpd hits top of the CPU and memory cycle and page consequently take some time to load. Can ...
Quintin Par's user avatar
  • 4,443
0 votes
1 answer
309 views

what's the best webserver configuration for this setup?

I have a webserver running on an IBM blade, hardware configuration is: Intel Xeon E5506 x 2 (8 cores) 12G mem SAS disk raid1 I use this box as a dedicated webserver serving a dozen of simple php ...
Long Cheng's user avatar
8 votes
2 answers
3k views

Tuning Linux's IPv6 stack

I'm working on a Linux network deice, and there are some TCP/IP settings that don't seem to have IPv6 equivalents. IP forwarding is a common setting, and available in both stacks net.ipv4.ip_forward ...
JimB's user avatar
  • 1,924
1 vote
3 answers
604 views

Config MySQL to maximum speed and memory

I have a server, 8 cores, 12 GB RAM. This server is only used to run MySQL. So, help me config /etc/my.cnf to maximum speed, memory for MySQL.
Khoa Of GOd's user avatar
5 votes
3 answers
4k views

Filesystem/Options for intensive random I/O

I'm planning to (privately) deploy a server that will be hammered with random I/Os in files ranging from 100MB to 50GB. The requests will range from 128 KB to 4MB. The profile will be 50:50 concerning ...
leto's user avatar
  • 281
5 votes
1 answer
5k views

Nginx & Passenger - failed (11: Resource temporarily unavailable) while connecting to upstream

I have an Nginx and Passenger setup that is proving problematic. At relatively low loads the server seems to get backed up and start churning results like this into the error.log: connect() to unix:/...
Toby Hede's user avatar
  • 309
15 votes
4 answers
51k views

kjournald reasons for high usage

I'm trying to figure out why is kjournald going crazy on my machine. It's an 8-core box with loads of memory. It's got ~50% cpu load. The iotop doesn't seem to point at any specific processes - some ...
viraptor's user avatar
  • 1,306
0 votes
2 answers
197 views

How do I calculate the amount of tuning needed for my server?

I have a server which is running a few discrete Python, Java application which most of the time imports data into a PostGreSQL database. I would like to know from people out there who have experience ...
Low Kian Seong's user avatar
0 votes
1 answer
1k views

Nginx causing high load with not many active connections

I have a linux machine 64bit (centos5.5), 2.83GHz Q9550, 6gb ram and a single SATA 500gb drive. From this machine I only serve thumbnails, most around 10kb in size and at this point there are about 7 ...
Mr.Boon's user avatar
  • 1,481
1 vote
3 answers
6k views

Solaris tcp_keepalive_abort_interval

There is a section in Solaris reference manual for tcp_keepalive_abort_interval. However, it doesn't appear in ndd /dev/tcp \? listing. # uname -srvmpi SunOS 5.10 Generic_142909-17 sun4us sparc FJSV,...
fglez's user avatar
  • 336
0 votes
1 answer
1k views

Setting MySQL table_cache variable

Greetings, I've set the table_cache variable in /etc/mysql/my.cnf on Ubuntu to 512, but the reported value is only 64. How can I fix this? Thanks
kobrien's user avatar
  • 131
2 votes
4 answers
2k views

Tune SQL Server Express using Profiler?

I have a SQL Server 2005 database... a copy of it is running in development on a full version of SQL server. Another copy is running in SQL Server 2005 Express on a web server. I've used SQL Profiler ...
Glen Little's user avatar
1 vote
1 answer
290 views

Reducing max memory settings in SQL 2005

We have a 2003 cluster with 32GB of memory. It hosts two SQL 2005 DB instances, one Reporting instance and runs SSIS packages throughout the day. The main instance is set to 22GB of memory, the ...
Sam's user avatar
  • 2,030
7 votes
4 answers
11k views

Apache2 PHP Site - Hitting MaxClients limit - diagnosing?

We have a moderate-traffic site (roughly 20,000 hits a day), running a PHP/MySQL app on Apache 2.2, Ubuntu 9.10 Server, from an Amazon EC2 c1.small instance (1.7 Gb of RAM). We had issues with the ...
victorhooi's user avatar
8 votes
5 answers
7k views

How to fine-tune our MySQL server?

MySQL is not my thing, yet I need to fine-tune one of our servers. Here are the requirements/specs: The MySQL server has only one significant database We only have one "type" of application ...
Julien Genestoux's user avatar
105 votes
8 answers
220k views

What limits the maximum number of connections on a Linux server?

What kernel parameter or other settings control the maximum number of TCP sockets that can be open on a Linux server? What are the tradeoffs of allowing more connections? I noticed while load testing ...
Ben Williams's user avatar
  • 2,396
40 votes
5 answers
82k views

How to identify I/O bottlenecks on a Linux server?

How do you determine that the performance of your Linux server is I/O bound and, perhaps more importantly, what process or processes are casuing the problem?
cletus's user avatar
  • 10.1k