Maximizing Linux (CentOS) For Maximum Concurrent Users
Jul 28, 2009
I am running lighttpd and eccelerator.
I have stripped the php-cgi.
I have tried forking anywhere from 50 to 300 to 1000 fastcgi children with PHP_FCGI_CHILDREN (through lighttpd, I'll attempt to do with same with spawn-fastcgi and fpm)
I am using to lighttpd's lighttpd-status to estimate concurrent connections.
When I refresh the panel, it shows that there are around 100-150 connections and around 150 requests/s in the last 5 seconds.
My vmstats show that CPU is 98% idle. Blocks written/read is neglible. MySql key_buffer set to 2gb and I'm pretty sure it's not mysql. The overwhelming majority of requests do not access mysql.
EDIT: Uh oh, I just realized that tcp_mem could be a huge bottle neck.
I just set it to:
net.ipv4.tcp_mem = 4096000 87380000 4194304000
It was previously:
net.ipv4.tcp_mem = somenumber somenumber 393,216 <<<--- WTF!
x1000 for my read values (it's an access server only). I can't benchmark the server right now so let me know if you have any suggestions besides this. I do think that this was the problem. When under load images could not be accessed either.
I'm on a vps using Dell PowerEdge Servers and 750 GB of transfer.
I have concurrent users settings to where i now have them at "50" and I'm wondering how much higher i can go without troubles.
My app is a perl cgi script in flat files and 95% of visitors will pass through my domain without seeing my webpage. They are only there approx 1 second, maybe 2 as they are quickly redirected from this platform.
My host has a custom solution installed to check for apache stalls every few minutes and it will restart apache when it sticks - and it will stick from time to time.
Just now i do about 75000 per day but plan to double to 150,000 next week and soon after will triple to 225,000 visitors per day.
Should i increase concurrent users now in prep for the increase to 150k or at what level.
Please give some suggestions for concurrent settings at future traffic levels. This host has a multiple server set up in case one fails - i should be good, i think.
I try to search and not found the solutions to limit concurrent of db users to connect to MySQL in same time for example:
Limit user root to connect to MySQL maximum 5 connections in same time
There have max_connections setting but it limit for all users in all connection to MySQL.
But I found that in version 4.1.x there have max_connections property in user table (Users and global privileges) of mysql database, this setting is limit connection in 60 minutes.
I would like to know if there any setting or code modify for this solution that I want.
Like the topic suggested, anybody have a rough estimate of how many concurrent users game websites such as wildtangent and instantaction have? Also, what kind of server configuration would be necessary to support those kind of users assuming you have 1 server for web and 1 for database.
I've setup MDaemon mail server on my local PC to send personal emails to Yahoo Groups.
Maximum recipients per message is set to 100 for the clients.
When there are more than 1 messages pending to be sent to yahoogroups.com, mdaemon creates a message to be sent to this domain and add 31 users in To (BCC) list and the message fails as it should, saying "too many recipients".
There should only be one recipient in To list, but I could not locate the setting where to set maximum recipients for outgoing email
I'm also searching mdaemon forums, but as i get quick response from WHT...
Is it possible to run two concurrent VPN connections using the Linux Cisco VPN client? We need to have one server be able to communicate over two different vendors gateways.
Do we need to possibly add an additional NIC to the server first?
When we try to connect to another profile we get the error:
Initializing the VPN connection.
Secure VPN Connection terminated locally by the Client
I am planning to get a Juniper firewall, but due to SSG140 has a maximum of 48,000 concurrent sessions per second, so it triggers me how do I measure the concurrent session of a linux server of the total throughput instead of just port 80?
I have noticed that the CPU on my VPS maxes out. This occurs when there are many concurrent visitors to any of the 7 domains. 6 of the domains run Wordpress and 1 runs php-bb forum. When I run top during high cpu I see multiple "php-cgi":
I've purchased a VPS with CentOS 5 on and am looking to get it all up and running myself (Never done anything Linux based before but don't mind learning). I've gotten as far as installing LAMP + Webmin on the server, outsourced my DNS to zoneedit and email to Google and am now trying to configure other parts. I'm currently stuck on two things.
1. I'm trying to configure my FTP server. I've installed and am able to run it and connect to it myself as root but I can't figure out how to get it my html folder. Its only got files like .bash_history and .bash_logout in view. Also trying to do this through Webmin cause I've got no idea where to find anything on the command line other then proftd.conf
2. I'm trying to add users to the server but again I'm unsure on how to set the permissions for it. I can create it but it comes up with the error /dev/null Permission Denied a couple of times when I log in.
My Customers and I have Problems connecting to IMAP-Server. By moving through IMAP Folders I get the Massage "Unable to connect to your IMAP server. You may have exceeded the maximum number of connections to this server"
I know this Article: [URL] ... and all the other related to this issue.
I have this error when i put import to mysql database
Code: #1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '<script></script><p>ERROR: Maximum execution time of 300 seconds exceeded (Util.' at line 244
I have in domain > doemainname > max_execution_time Standaard Geef een aangepaste waarde op 0
and insert in usr/local/psa/admin/htdocs/domains/databases/phpmyadmin in the file config.sample.inc.php following command $cfg['ExecTimeLimit'] = 70000;
Every time I log on plesk 11.09 I get an email from admin saying that due to maximum number of failed login attempts for admin, the account was blocked for 30 minutes.
First, I do not get failed login attempts, I log in every time.
Two, the account is not blocked, I can log in, out and back in as many times as I want without problem except that I get this email everytime.
The upgrade has an error when manage the users database.
PRODUCT, VERSION, VERSION OF MICROUPDATE, OPERATING SYSTEM, ARCHITECTURE OS Microsoft Windows Server 2008 R2 Service Pack 1 x64 Panel version 11.5.30 Update #13, last updated at Sept 1, 2013 03:30 PM
PROBLEM DESCRIPTION In a costumer panel have a one database MSSQL, and assign to this DB 3 users, but the tab option "Users" don't work fot his costumer and show this error:
Error Javascript: TypeError: template is null this.template = template.toString(); in protototype.js 8472831 (lÃnea 807)
ACTUAL RESULT Error Javascript: TypeError: template is null this.template = template.toString(); in protototype.js 8472831 (lÃnea 807)
EXPECTED RESULT Show users in the tab users for database.
I am trying to install Magento on my apache server. I am running into the dreaded mcrypt issue as Magento needs it to run. I have now been googling for the past few hours and have gotten nowhere.
Here are my details:
Linux Centos 5.5 PHP 5.3.3 x86_64 Plesk 12
I have tried installing all sorts of different repos and it just isn't working.
When I try to install using # yum install php-mcrypt I get the following:
Loaded plugins: fastestmirror Package php-mysql is obsoleted by php-mysqlnd, trying to install php-mysqlnd-5.5.13-3.el5.remi.x86_64 instead --> Processing Dependency: php53-gd for package: psa-php53-configurator --> Processing Dependency: php53-imap for package: psa-php53-configurator
A software developer has uncovered a bug in most versions of Linux that could allow untrusted users to gain complete control over the open-source operating system.
The null pointer dereference flaw was only fixed in the upcoming 2.6.32 release candidate of the Linux kernel, making virtually all production versions in use at the moment vulnerable. While attacks can be prevented by implementing a common feature known as mmap_min_addr, the RHEL distribution, short for Red Hat Enterprise Linux, doesn't properly implement that protection, Brad Spengler, who discovered the bug in mid October, told The Register.
Read the complete article at The Register. New kernels are available for Redhat and CentOS (obviously), and likely others who may be affected.
My reseller have got one plan, where option "Gestion de l'accès au serveur via SSH" (Manage SSH access to server) is on "Peut autoriser l'accès uniquement à un environnement chrooté" (Can autorize access only in chrooted environment).
This plan contains only one subscription in which I would like to permit users to use sftp. If I go in the subscription, and then I click on "Customize subscription", I can see option "Gestion de l'accès au serveur via SSH" (Manage SSH access to server) is on "Peut autoriser l'accès uniquement à un environnement chrooté" (Can autorize access only in chrooted environment)...
=> So same than in the plan.
After that, when I click on subscription => WebSites and Domain => One domain => FTP Access and I choose a ftp user, I don't have any option to allow ssh access to the user.
Is it possible to query for a list of system users using the API RPC? I know it's possible with a MySQL query
Code: select id, login, account_id from sys_users order by login;
I've searched through the API RPC manual, but I don't see a way to do this. I always have to specify a filter, I can't find a way to just query for all users.
After some recents updates (currently running on: 12.0.18 Update #19) appeared a problem with connecting to FTP for passive mode users:
Connect ok! "/" is the current directory Get directory 227 Entering Passive Mode 550 Access is denied.
Server logs: /var/log/messages Oct 14 12:11:26 host xinetd[3692]: START: ftp pid=2709 from=::ffff:xxx.xxx.xxx.xxx Oct 14 12:11:26 host proftpd[2709]: processing configuration directory '/etc/proftpd.d' Oct 14 12:11:26 host proftpd[2709]: yyy.yyy.yyy.yyy (xxx.xxx.xxx.xxx[xxx.xxx.xxx.xxx]) - FTP session opened.
But: /var/log/secure:
Oct 14 12:11:26 host proftpd: PAM unable to dlopen(/lib64/security/pam_stack.so): /lib64/security/pam_stack.so: cannot open shared object file: No such file or directory Oct 14 12:11:26 host proftpd: PAM adding faulty module: /lib64/security/pam_stack.so Oct 14 12:11:26 host proftpd: pam_listfile(proftpd:auth): Couldn't open /etc/ftpusers Oct 14 12:11:26 host proftpd[2709]: yyy.yyy.yyy.yyy (xxx.xxx.xxx.xxx[xxx.xxx.xxx.xxx]) - USER client: Login successful.
ad1: yes, i do have passive ports configured in /etc/proftpd.conf and FW is properly configured ad2: everything was fine until recent updates ad3: this is happening only for passive users only ad4: we are experiencing this issues across all Plesk instances [6x] on CentOS 6.5 with 12.0.18 Update #19
i have a vps, and im current use lighttpd, but i want move to litespeed Standard. And i see they limit Max Concurrent Connections =150 on standard version.
but what is Max Concurrent Connections? where can i find it.
and is it the number connection via port 80 (netstat -nt | grep :80 | wc -l)?
I want to create a webpage where users can make a SRV record. I thought this is possible with the Plesk API but i dont have any expierance with the API. How to create it?
I am experiencing a weird issue after a Plesk upgrade (from 11 to 12, installed on Ubuntu 12.04).
FTP/SFTP is not working for all users in one specific domain. When using the latest Filezilla client, I receive the following error when I try to connect in SFTP with the main user of this domain
Error: Received unexpected end-of-file from SFTP server Error: Could not connect to serverClick to expand...
I have plesk12 set up but when i set a mail (dovecot) password, it gets stored in plain text (which I can verify by running /usr/local/psa/admin/sbin/mail_auth_view ). I would like to change this default setting to be encrypted.
