Admin? Anyone? Let's say Anyhelp is appreciated!
This article is to show how simple is to use an SSD cache device to a hard disk drive. We also included statistics and graphs for several days of usage in one of our streaming servers.
Our setup:
We included several graphs of this setup from one of our static media servers serving HLS video streaming.
The effectiveness of the cache is around 2-4 times at least!
Here is how you can install a BOINC client and attach it to a project (SETI). We use only command line tools, not GUI involved here. You can attach to a project and do some various administrative work with
boinccmd
like to get the progress of the currently running project tasks, project info, manage tasks and more.
Steps to install and run a (SETI) project:
The installation of the BOINC client requires using EPEL repository. Become root user and install Epel repository and Boinc client.
sudo su yum update -y yum install -y epel-release yum install -y boinc-client systemctl start boinc-client systemctl enable boinc-client
Here we use our SETI project to attach the server to it. There are two ways to attach to a project:
To attach to a project your boinc client must be up and running and to use boinccmd – The command line interface to the BOINC client:
cd /var/lib/boinc boinccmd --project_attach "http://setiathome.berkeley.edu/" "111111_22222233333344444444444555555555"
The first argument of “–project_attach” is the URL address of the project site, in this case, SETI with “http://setiathome.berkeley.edu/” and the account key of our account is 111111_22222233333344444444444555555555 (this is not the real one!). After successful attach your client will start to download the project files and begin to work on units:
[myuser@compute1 ~]# boinccmd --get_tasks ======== Tasks ======== 1) ----------- name: blc36_2bit_guppi_58406_31023_HIP20352_0115.19579.818.22.45.146.vlar_0 WU name: blc36_2bit_guppi_58406_31023_HIP20352_0115.19579.818.22.45.146.vlar project URL: http://setiathome.berkeley.edu/ received: Tue Apr 2 13:38:07 2019 report deadline: Sat May 25 18:37:49 2019 ready to report: no state: downloaded scheduler state: scheduled active_task_state: EXECUTING app version num: 800 resources: 1 CPU estimated CPU time remaining: 4843.738587 CPU time at last checkpoint: 1326.038000 current CPU time: 1366.303000 fraction done: 0.170349 swap size: 54 MB working set size: 52 MB 2) ----------- name: blc34_2bit_guppi_58406_26949_HIP20491_0103.21476.0.21.44.1.vlar_1 WU name: blc34_2bit_guppi_58406_26949_HIP20491_0103.21476.0.21.44.1.vlar project URL: http://setiathome.berkeley.edu/ received: Tue Apr 2 13:43:18 2019 report deadline: Sat May 25 18:42:59 2019 ready to report: no state: downloaded scheduler state: uninitialized active_task_state: UNINITIALIZED app version num: 800 resources: 1 CPU estimated CPU time remaining: 5838.283108 3) ----------- ....
You can see all the tasks – the one running at the moment and those on the queue.
When the “fraction done” reaches 1.0 the tasks is ready to report.
To view all running work units and some useful links in the project site like forums, account, preferences, recent tasks, list of the computers on which you are running SETI@Home, team information and more you can use “–get_simple_gui_info” (some of the data here are changed):
[myuser@compute1 ~]# boinccmd --get_simple_gui_info ======== Projects ======== 1) ----------- name: SETI@home master URL: http://setiathome.berkeley.edu/ user_name: neoX team_name: neoX Group resource share: 150.000000 user_total_credit: 14376490.970263 user_expavg_credit: 25085.116699 host_total_credit: 0.000000 host_expavg_credit: 0.000000 nrpc_failures: 2 master_fetch_failures: 0 master fetch pending: no scheduler RPC pending: no trickle upload pending: no attached via Account Manager: no ended: no suspended via GUI: no don't request more work: no disk usage: 0.000000 last RPC: Tue Apr 2 17:19:56 2019 project files downloaded: 1554212310.422403 GUI URL: name: Message boards description: Correspond with other users on the SETI@home message boards URL: http://setiathome.berkeley.edu/forum_index.php GUI URL: name: Help description: Ask questions and report problems URL: http://setiathome.berkeley.edu/forum_help_desk.php GUI URL: name: Account description: View your account information URL: http://setiathome.berkeley.edu/home.php GUI URL: name: Preferences description: View and modify your computing preferences URL: http://setiathome.berkeley.edu/prefs.php?subset=global GUI URL: name: Tasks description: View your recent tasks URL: http://setiathome.berkeley.edu/results.php?userid=111111 GUI URL: name: Computers description: View a list of the computers on which you are running SETI@Home URL: http://setiathome.berkeley.edu/hosts_user.php?userid=111111 GUI URL: name: Team description: View information about your team: neoX Group URL: http://setiathome.berkeley.edu/team_display.php?teamid=22222 GUI URL: name: Donate description: Donate to SETI@home URL: http://setiathome.berkeley.edu/sah_donate.php jobs succeeded: 16 jobs failed: 0 elapsed time: 107328.542101 cross-project ID: 33333333333333333333333333333333 ======== Tasks ======== 1) ----------- name: blc34_2bit_guppi_58406_27281_HIP20917_0104.20977.818.21.44.184.vlar_1 WU name: blc34_2bit_guppi_58406_27281_HIP20917_0104.20977.818.21.44.184.vlar project URL: http://setiathome.berkeley.edu/ received: Tue Apr 2 13:43:18 2019 report deadline: Sat May 25 18:42:59 2019 ready to report: no state: downloaded scheduler state: scheduled active_task_state: EXECUTING app version num: 800 resources: 1 CPU estimated CPU time remaining: 4658.869936 CPU time at last checkpoint: 1902.641000 current CPU time: 1949.207000 fraction done: 0.202014 swap size: 58 MB working set size: 56 MB 2) ----------- name: blc34_2bit_guppi_58406_28625_HIP21029_0108.20913.818.21.44.250.vlar_1 WU name: blc34_2bit_guppi_58406_28625_HIP21029_0108.20913.818.21.44.250.vlar project URL: http://setiathome.berkeley.edu/ received: Tue Apr 2 13:43:18 2019 report deadline: Sat May 25 18:42:59 2019 ready to report: no state: downloaded scheduler state: scheduled active_task_state: EXECUTING app version num: 800 resources: 1 CPU estimated CPU time remaining: 4586.517845 CPU time at last checkpoint: 1903.475000 current CPU time: 1909.324000 fraction done: 0.214406 swap size: 58 MB working set size: 56 MB 3) ----------- name: blc34_2bit_guppi_58406_27281_HIP20917_0104.20977.818.21.44.149.vlar_0 WU name: blc34_2bit_guppi_58406_27281_HIP20917_0104.20977.818.21.44.149.vlar project URL: http://setiathome.berkeley.edu/ received: Tue Apr 2 13:43:18 2019 report deadline: Sat May 25 18:42:59 2019 ready to report: no state: downloaded scheduler state: scheduled active_task_state: EXECUTING app version num: 800 resources: 1 CPU estimated CPU time remaining: 4643.434099 CPU time at last checkpoint: 1902.425000 current CPU time: 1904.189000 fraction done: 0.204658 swap size: 58 MB working set size: 56 MB 4) ----------- name: blc34_2bit_guppi_58406_26949_HIP20491_0103.21476.0.21.44.21.vlar_1 WU name: blc34_2bit_guppi_58406_26949_HIP20491_0103.21476.0.21.44.21.vlar project URL: http://setiathome.berkeley.edu/ received: Tue Apr 2 13:43:18 2019 report deadline: Sat May 25 18:42:59 2019 ready to report: no state: downloaded scheduler state: scheduled active_task_state: EXECUTING app version num: 800 resources: 1 CPU estimated CPU time remaining: 4636.707813 CPU time at last checkpoint: 1845.896000 current CPU time: 1862.998000 fraction done: 0.205810 swap size: 54 MB working set size: 52 MB 5) ----------- name: blc34_2bit_guppi_58406_28965_HIP20350_0109.21465.0.22.45.59.vlar_1 WU name: blc34_2bit_guppi_58406_28965_HIP20350_0109.21465.0.22.45.59.vlar project URL: http://setiathome.berkeley.edu/ received: Tue Apr 2 13:43:18 2019 report deadline: Sat May 25 18:42:59 2019 ready to report: no state: downloaded scheduler state: scheduled active_task_state: EXECUTING app version num: 800 resources: 1 CPU estimated CPU time remaining: 4665.477705 CPU time at last checkpoint: 1781.304000 current CPU time: 1805.969000 fraction done: 0.200882 swap size: 58 MB working set size: 56 MB 6) ----------- name: blc34_2bit_guppi_58406_28625_HIP21029_0108.20913.818.21.44.210.vlar_1 WU name: blc34_2bit_guppi_58406_28625_HIP21029_0108.20913.818.21.44.210.vlar project URL: http://setiathome.berkeley.edu/ received: Tue Apr 2 13:43:18 2019 report deadline: Sat May 25 18:42:59 2019 ready to report: no state: downloaded scheduler state: scheduled active_task_state: EXECUTING app version num: 800 resources: 1 CPU estimated CPU time remaining: 4675.696451 CPU time at last checkpoint: 1780.113000 current CPU time: 1784.886000 fraction done: 0.199132 swap size: 58 MB working set size: 56 MB 7) ----------- name: blc34_2bit_guppi_58406_28965_HIP20350_0109.21465.0.22.45.101.vlar_1 WU name: blc34_2bit_guppi_58406_28965_HIP20350_0109.21465.0.22.45.101.vlar project URL: http://setiathome.berkeley.edu/ received: Tue Apr 2 13:43:18 2019 report deadline: Sat May 25 18:42:59 2019 ready to report: no state: downloaded scheduler state: scheduled active_task_state: EXECUTING app version num: 800 resources: 1 CPU estimated CPU time remaining: 4705.804477 CPU time at last checkpoint: 1711.990000 current CPU time: 1768.862000 fraction done: 0.193975 swap size: 54 MB working set size: 52 MB 8) ----------- name: blc34_2bit_guppi_58406_28625_HIP21029_0108.20913.818.21.44.254.vlar_1 WU name: blc34_2bit_guppi_58406_28625_HIP21029_0108.20913.818.21.44.254.vlar project URL: http://setiathome.berkeley.edu/ received: Tue Apr 2 13:43:18 2019 report deadline: Sat May 25 18:42:59 2019 ready to report: no state: downloaded scheduler state: scheduled active_task_state: EXECUTING app version num: 800 resources: 1 CPU estimated CPU time remaining: 4928.870679 CPU time at last checkpoint: 1422.330000 current CPU time: 1466.627000 fraction done: 0.155767 swap size: 54 MB working set size: 52 MB
Here are the options you can use in version 7.14.2:
[myuser@compute1 ~]# boinccmd --help usage: boinccmd [--host hostname] [--passwd passwd] [--unix_domain] command default hostname: localhost default password: contents of gui_rpc_auth.cfg Commands: --acct_mgr attach URL name passwd attach to account manager --acct_mgr info show current account manager info --acct_mgr sync synchronize with acct mgr --acct_mgr detach detach from acct mgr --client_version show client version --create_account URL email passwd name --file_transfer URL filename op file transfer operation op = retry | abort --get_app_config URL show app config for given project --get_cc_status --get_daily_xfer_history show network traffic history --get_disk_usage show disk usage --get_file_transfers show file transfers --get_host_info --get_message_count show largest message seqno --get_messages [ seqno ] show messages > seqno --get_notices [ seqno ] show notices > seqno --get_project_config URL --get_project_status show status of all attached projects --get_proxy_settings --get_simple_gui_info show status of projects and active tasks --get_state show entire state --get_tasks show tasks --get_old_tasks show reported tasks from last 1 hour --join_acct_mgr URL name passwd same as --acct_mgr attach --lookup_account URL email passwd --network_available retry deferred network communication --project URL op project operation op = reset | detach | update | suspend | resume | nomorework | allowmorework | detach_when_done | dont_detach_when_done --project_attach URL auth attach to project --quit tell client to exit --quit_acct_mgr same as --acct_mgr detach --read_cc_config --read_global_prefs_override --run_benchmarks --set_gpu_mode mode duration set GPU run mode for given duration mode = always | auto | never --set_host_info product_name --set_network_mode mode duration set network mode for given duration mode = always | auto | never --set_proxy_settings --set_run_mode mode duration set run mode for given duration mode = always | auto | never --task url task_name op task operation op = suspend | resume | abort
[myuser@compute1 ~]# yum search boinc Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: mirror.checkdomain.de * epel: mirror.wiuwiu.de * extras: mirror.checkdomain.de * updates: mirror.checkdomain.de ============================================================================ N/S matched: boinc ============================================================================ boinc-client.x86_64 : The BOINC client boinc-client-devel.x86_64 : Development files for boinc-client boinc-client-doc.noarch : Documentation files for boinc-client boinc-client-static.x86_64 : Static libraries for boinc-client boinc-manager.x86_64 : GUI to control and monitor boinc-client Name and summary matches only, use "search all" for everything.
If you get the follwoing error:
root@srv ~ # boinccmd --project_attach "http://boinc.bakerlab.org/rosetta/" "1111_111111111111111111111111111" Operation failed: authentication error
You must change the directory to “/var/lib/boinc” and run the command again. You may chown the directory to the boinc user. A directory for the project is created under “projects/” and a configuration file is created with name “account_boinc.bakerlab.org_rosetta.xml”.
root@srv ~ # cd /var/lib/boinc
root@srv /var/lib/boinc # boinccmd --project_attach "https://boinc.bakerlab.org/rosetta/" "1111_111111111111111111111111111"
root@srv chown -R boinc:boinc /var/lib/boinc
root@srv /var/lib/boinc # ls -altr projects/boinc.bakerlab.org_rosetta/
total 8
drwxrwx--x 4 boinc boinc 4096 Apr 4 03:01 ..
drwxrwx--x 2 boinc boinc 4096 Apr 4 03:01 .
root@srv /var/lib/boinc # cat account_boinc.bakerlab.org_rosetta.xml
<account>
<master_url>https://boinc.bakerlab.org/rosetta/</master_url>
<authenticator>1111_111111111111111111111111111</authenticator>
<project_name>Rosetta@home</project_name>
<project_preferences>
<resource_share>15</resource_share>
<project_specific>
<color_scheme>Tahiti Sunset</color_scheme>
</project_specific>
</project_preferences>
<gui_urls>
<gui_url>
<name>Message boards</name>
<description>Correspond with other users on the Rosetta@home message boards</description>
<url>http://boinc.bakerlab.org/rosetta/forum_index.php</url>
</gui_url>
<gui_url>
<name>Your account</name>
<description>View your account information</description>
<url>http://boinc.bakerlab.org/rosetta/home.php</url>
</gui_url>
<gui_url>
<name>Your tasks</name>
<description>View the last week or so of computational work</description>
<url>http://boinc.bakerlab.org/rosetta/results.php?userid=xxxx</url>
</gui_url>
</gui_urls>
</account>
If you want to use software raid device in your Gentoo Linux system (init boot, not systemd) with boot partition resided in the raid for better redundancy but using metadata 1.2 version you won’t have autodetection feature on boot and there are some additional steps you may consider!
Linux kernel’s autodetection feature of the software raid is only for superblock (metadata) version 0.90!
If you create a software raid with superblock version 1, 1.1 or 1.2 you want to boot from it you must use:
Several reports in the Internet with such error:
[22-Mar-2019 21:35:20 Africa/Tunis] PHP Warning: Unknown: Failed to write session data (memcached). Please verify that the current setting of session.save_path is correct (PERSISTENT=2 10.10.10.10:11211) in Unknown on line 0 [22-Mar-2019 21:35:21 Africa/Lagos] PHP Warning: Unknown: Failed to write session data (memcached). Please verify that the current setting of session.save_path is correct (PERSISTENT=2 10.10.10.10:11211) in Unknown on line 0 [22-Mar-2019 13:35:21 America/Los_Angeles] PHP Warning: Unknown: Failed to write session data (memcached). Please verify that the current setting of session.save_path is correct (PERSISTENT=2 10.10.10.10:11211) in Unknown on line 0
But no real solutions worked for us. Here is our setup:
Several web servers servers (using php-fpm – fastcgi) connect to a single memcached server to share sessions.
The PHP configuration (php.ini) is as simple as that:
.... session.save_handler = memcached session.save_path = "PERSISTENT=2 10.10.10.10:11211" ....
This is how you can enable PHP sessions to be stored in the memcached server with IP 10.10.10.10 and tell the driver to use persistent connections. Note we use the binary PHP module memcached, not memcache, which is the old driver.
The persistence is handled by the PHP module, not the library, which it wraps and it is per process not per all PHP fpm (fastcgi) processes.
Apparently, sometimes this functionality just get corrupted and many of those errors begin to appear in the logs – most of the time a reload of the php-fpm after a long period of time. Even a restart did not help, so the real solution, which always works for us is
to change the ID of the “PERSISTENT=”
so just change to:
session.save_path = "PERSISTENT=234 10.10.10.10:11211"
No matter of the ID just some new one, not used previous time! And everything continues smooth!
The aim of this article is to show you the simplest way you can achieve your monitoring Nagios system to make a phone call on a critical, in our example CRITICAL host DOWN (the host is unreachable)! You will not need any server software to setup (including VoiceOverIP server), the only thing you will need is an account in https://www.twilio.com/, which even could be a free/trial account. The idea here is to be simple, cheap and easy to be accomplished.
To summarize it up:
to make a phone call to a real phone number on a CRITICAL Nagios notification
Here is what you need:
The idea here is to make a phone call on a really CRITICAL issue to be able to wake up the person on duty to check the monitoring system and the SMS messages he received! So the phone call might not be accepted, at all – the ring of the phone (or continues vibrating of your smart band on your wrist!) should be enough to get a second different type of notification after the first (only and most cases only?) SMS messaging (which has the infromation for the problem!).
Keep on reading!
Selinux could sometime mess up with your setup. Let’s say you configured your rsync daemon but still, you get the error related to permissions when executing the rsync to copy files!
rsync: opendir "/." (in backup2) failed: Permission denied (13)
Apparently, the rsync client connects to the server and it finds there is a section name “backup2”, but still no permission despite you explicitly set in the section uid and ig to be root (uid=0 and gid=0 in the section)!
The most common reason is
selinux denies rsync process to open the directory exported by the path in your rsync configuration file.
By default, Selinux will deny access to any of the files and directories in your system! In most cases here what can you help:
setsebool -P rsync_export_all_ro=1
rsync_export_all_ro will export any files and directories read-only and requests like above will not be denied.
The capital letter “-P” is to set it permanently for the system over reboots.
Keep on reading!
We upgraded one of our servers and at first did not notice this error. Soon logs began to fill with this error:
Fatal error: Uncaught Error: Class 'DOMDocument' not found in /var/www/htdocs/site1/wp-content/plugins/all-in-one-seo-pack/aioseop_class.php:4501 Stack trace: #0 /var/www/htdocs/site1/wp-content/plugins/all-in-one-seo-pack/aioseop_class.php(4056): All_in_One_SEO_Pack->get_prev_next_links(Object(WP_Post)) #1 /var/www/htdocs/site1/wp-includes/class-wp-hook.php(286): All_in_One_SEO_Pack->wp_head('') #2 /var/www/htdocs/site1/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array) #3 /var/www/htdocs/site1/wp-includes/plugin.php(465): WP_Hook->do_action(Array) #4 /var/www/htdocs/site1/wp-includes/general-template.php(2668): do_action('wp_head') #5 /var/www/htdocs/site1/wp-content/themes/twentysixteen/header.php(21): wp_head() #6 /var/www/htdocs/site1/wp-includes/template.php(704): require_once('/var/www/h...') #7 /var/www/htdocs/site1/wp-includes/template.php(653): load_template('/var/www/h...', true) #8 /var/www/htdocs/site1/wp-incl in /var/www/htdocs/site1/wp-content/plugins/all-in-one-seo-pack/aioseop_class.php on line 4501
Apparently, we missed to install all PHP extensions as before and one of our WordPress plugins (All in One SEO Pack) began to throw this nasty error and blank pages, where the error is supposed to be shown!
The fix is easy enough just install PHP-XML
yum -y install php-xml
yum -y install php72u-xml
sudo apt install -y php-xml php-dom
Just add to your current USE the following “xml” in your /etc/portage/make.conf and emerge (be sure “xml” is in USE emerge output, not “-xml”!):
srv1 ~ # emerge -va --nodeps php These are the packages that would be merged, in order: [ebuild R ] dev-lang/php-7.2.10:7.2::gentoo USE="acl apache2 bcmath berkdb bzip2 calendar cgi cli ctype curl exif fileinfo filter fpm ftp gd gdbm hash iconv ipv6 json mhash mysql mysqli nls opcache pcntl pdo phar posix readline session sharedmem simplexml snmp soap sockets sqlite ssl tokenizer truetype unicode xml xmlreader xmlrpc xmlwriter zip zlib -argon2 -cdb -cjk -coverage -debug -embed -enchant -firebird -flatfile -gmp -imap -inifile -intl -iodbc -kerberos -ldap -ldap-sasl -libedit -libressl -lmdb -mssql -oci8-instant-client -odbc -phpdbg -postgres -qdbm -recode (-selinux) -session-mm -sodium -spell -systemd -sysvipc -test -threads -tidy -tokyocabinet -wddx -webp -xpm -xslt -zip-encryption" 0 KiB
Here is how our WordPress page looks like with the error:
<!DOCTYPE html>
<html lang="en-US" class="no-js">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="profile" href="http://gmpg.org/xfn/11">
<link rel="pingback" href="https://ahelpme.com/xmlrpc.php">
<script>(function(html){html.className = html.className.replace(/\bno-js\b/,'js')})(document.documentElement);</script>
<title>How to compile xmr-stak (2.4.5) under CentOS 7 for CPU mining cryptocurrencies | Any IT here? Help Me! - Part 2</title>
<!-- All in One SEO Pack 2.12 by Michael Torbert of Semper Fi Web Design[387,517] -->
<br />
<b>Fatal error</b>: Uncaught Error: Class 'DOMDocument' not found in /var/www/htdocs/site1/wp-content/plugins/all-in-one-seo-pack/aioseop_class.php:4501
Stack trace:
#0 /var/www/htdocs/site1/wp-content/plugins/all-in-one-seo-pack/aioseop_class.php(4056): All_in_One_SEO_Pack->get_prev_next_links(Object(WP_Post))
#1 /var/www/htdocs/site1/wp-includes/class-wp-hook.php(286): All_in_One_SEO_Pack->wp_head('')
#2 /var/www/htdocs/site1/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array)
#3 /var/www/htdocs/site1/wp-includes/plugin.php(465): WP_Hook->do_action(Array)
#4 /var/www/htdocs/site1/wp-includes/general-template.php(2668): do_action('wp_head')
#5 /var/www/htdocs/site1/wp-content/themes/twentysixteen/header.php(21): wp_head()
#6 /var/www/htdocs/site1/wp-includes/template.php(704): require_once('/var/www/h...')
#7 /var/www/htdocs/site1/wp-includes/template.php(653): load_template('/var/www/h...', true)
#8 /var/www/htdocs/site1/wp-incl in <b>/var/www/htdocs/site1/wp-content/plugins/all-in-one-seo-pack/aioseop_class.php</b> on line <b>4501</b><br />
And here is what you can expect in your web server logs (nginx + php-fpm setup)
2019/02/23 03:36:14 [error] 27441#27441: *56837 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught Error: Class 'DOMDocument' not found in /var/www/htdocs/site1/root/wp-content/plugins/all-in-one-seo-pack/aioseop_class.php:4501
Stack trace:
#0 /var/www/htdocs/site1/root/wp-content/plugins/all-in-one-seo-pack/aioseop_class.php(4056): All_in_One_SEO_Pack->get_prev_next_links(Object(WP_Post))
#1 /var/www/htdocs/site1/root/wp-includes/class-wp-hook.php(286): All_in_One_SEO_Pack->wp_head('')
#2 /var/www/htdocs/site1/root/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array)
#3 /var/www/htdocs/site1/root/wp-includes/plugin.php(465): WP_Hook->do_action(Array)
#4 /var/www/htdocs/site1/root/wp-includes/general-template.php(2668): do_action('wp_head')
#5 /var/www/htdocs/site1/root/wp-content/themes/twentysixteen/header.php(21): wp_head()
#6 /var/www/htdocs/site1/root/wp-includes/template.php(704): require_once('/var/www/h...')
#7 /var/www/htdocs/site1/root/wp-includes/template.php(653): load_template('/var/www/h...', true)
#8 /" while reading response header from upstream, client: 66.249.79.133, server: ahelpme.com, request: "GET /linux/fedora/review-of-freshly-installed-fedora-29-kde-plasma-desktop-kde-gui/2/ HTTP/1.1", upstream: "fastcgi://192.168.0.12:9000", host: "ahelpme.com"
And keep in mind if your HTTP 405 codes get in your access logs:
10.10.10.2 - - [22/Feb/2019:05:20:34 +0000] "GET /xmlrpc.php HTTP/1.1" 405 53 "-" "Mozilla/5.0 (X11; Linux i686; rv:2.0.1) Gecko/20100101 Firefox/4.0.1" "-" 10.10.10.2 - - [22/Feb/2019:05:20:38 +0000] "GET /xmlrpc.php HTTP/1.1" 405 53 "-" "Mozilla/5.0 (X11; Linux i686; rv:2.0.1) Gecko/20100101 Firefox/4.0.1" "-"
If you enable this feature in your MySQL you could
increase your disk IO time and write by 8-10x times.
Generally, this feature could save your replication scheme if a power failure occurs or OS crash and it could guarantee that no transaction is lost from the binary log. When enabled the binary log is synchronized on disk before transactions are committed. You can check the manual here: https://dev.mysql.com/doc/refman/5.7/en/replication-options-binary-log.html#sysvar_sync_binlog and it also says there could be a great impact on disk writes but how many?
So here are two setups:
The impact of setting the sync_binlog=1 is 8-10 times the IO time and IO writes. Here is images of several hours of sync_binlog=1 and then we disabled it online:
As you can see the increase in the disk IO time and disk write IOPS are significant – somewhere between 5 and 6 times more! The load is not increased more than 1.5x as normal, but it should be noted the server is off-peak and it has plenty of RAM 32G. Still mush load when some other IO appears.
The decrease of the disk IO time and disk write IOPS are significant – somewhere between 5 and 6 times more! Everything back to normal.
As you can see the increase in the disk IO time and disk write IOPS are significant – somewhere between 8 and 10 times more! The load is not increased, but it should be noted the server is off-peak and it has plenty of RAM 192G. Still mush load when some other IO appears.
SET GLOBAL sync_binlog=0;
The impact of setting the sync_binlog=1 is also 8-10 times the IO time and IO writes. Here is images of several hours of sync_binlog=1 and then we disabled it online:
The decrease of the disk IO time and disk write IOPS are significant – somewhere between 8 and 10 times more and even more! Everything back to normal.
Just the period of the graphs are bigger. As you can see the increase in the disk IO time and disk write IOPS are significant – somewhere between 8 and 10 times more! The load is not increased, but it should be noted the server is off-peak and it has plenty of RAM 192G. Still mush load when some other IO appears.
Just the period of the graphs are bigger. The decrease of the disk IO time and disk write IOPS are significant – somewhere between 8 and 10 times more and even more! Everything back to normal.
SO BE CAREFUL now when upgrading from older versions like MySQL 5.1, 5.5, 5.6 – you would probably need to disable it in the MySQL configuration file my.cnf.
What a great piece of hardware is Dell Inspiron 7352! In the year 2015, this laptop was on the market with 8G DDR3L SODIMM and this was the maximum single SODIMM RAM available at the moment! Still, DELL had decided to make this laptop with memory slot not soldered on the motherboard! After around two years Crucial made available a single 16G DDR3L SODIMM – Crucial CT25664BF160B DDR3L 1600 MT/s PC3L-12800 SODIMM 204 Pin Memory 16gb and DELL made a BIOS update, which made the laptop to support 16G RAM!
This article is to confirm that
DELL Inspiron 13 7352 laptop (i7-5500U 2.40GHz) works perfectly with Crucial 16G DDR3L!
The BIOS is A08 (11/13/2015), probably it would work with all later version after A08, too! At present, there are newer BIOS versions, but we haven’t flashed our BIOS yet!
Keep on reading!
Finally, we do not have any more MySQL 5.6 servers. We upgraded our last part of the system with MySQL 5.6 to 5.7. In our opinion, this upgrade is one of the major referred to MySQL configuration file my.cnf – multiple deprecated directives are removed in this new 5.7 version so when upgrading you should remove them before restarting or starting the new version if you want to have running MySQL server instance.
Keep in mind our my.cnf are old, they are created with MySQL 5.0 and they are edited in every upgrade to a new version (5.0 to 5.1, 5.1 to 5.5, and 5.5 to 5.6), and when we needed a specific optimization for our workload. And this is only for our configuration, there surely are more deprecated/removed variables in the new version. Here is a good starting point – https://dev.mysql.com/doc/refman/5.7/en/upgrading-from-previous-series.html This article is not how to upgrade your old MySQL 5.6 to the new MySQL 5.7 it shows what problems you might have after you upgrade MySQL 5.6 to the new MySQL 5.7.
There are two parts of this article:
The error messages are included, too.
Some MySQL variables first get deprecated and then removed in later versions (some are just renamed) and if they are contained in the my.cnf configuration file your server will not start up at all. The MySQL log shows that the server starts and then throws an error about “unknown variable” and starts a shutdown procedure. So you end up without a database server and it is important to remove them from the configuration or find the new name of a renamed one.
2019-02-26T09:50:12.612950Z 0 [ERROR] unknown variable 'key_buffer=512M' 2019-02-26T09:50:36.361870Z 0 [ERROR] unknown variable 'thread_concurrency=6' 2019-02-26T09:51:17.658546Z 0 [ERROR] unknown variable 'thread_cache=10' 2019-02-26T09:51:32.473210Z 0 [ERROR] unknown variable 'innodb_additional_mem_pool_size=256M'
All four
key_buffer, thread_concurrency, thread_cache, innodb_additional_mem_pool_size
MySQL variables were removed and your server won’t start up if they are contained in the configuration. The “key_buffer” has been renamed to “key_buffer_size“ so replace it with key_buffer_size in your my.cnf. It’s important to replace it, because commenting it out would activate the default value and in this case 8M key_buffer_size, which is pretty low (in fact almost all default values of the MySQL variables are really low and it is a problem and a topic of discussions in many forums).
The “thread_cache” also renamed long ago to “thread_cache_size“, so replace it with thread_cache_size.
thread_concurrency and innodb_additional_mem_pool_size were removed long ago they first stopped doing anything and with this version, they removed the variables. As you can see old configuration files could carry on many old names over the years.
The important thing here is you must rename the ones, which got renamed and remove the ones, which got removed, because your server is not going to start up with them in the configuration.
Some default values of MySQL variables got changed and if you have not included it in the my.cnf configuration you might be really surprised how big an impact they have on the IO or even on the behavior of the SQL statements.
sync_binlog
– the default value was “0” (deactivated synchronization) and now it is “1” (bin log synchronization). This could greatly impact the performance of your MySQL database server with like 8-10 times more writes and IO disk wait time (really!!!) – you can see it here: (coming soon). So if you haven’t used this variable before you should put it in your my.cnf configuration for sure (in [mysqld] section):
sync_binlog=0
do not need to restart the server, just put in the my.cnf configuration file and open a mysql root console and execute:
SET GLOBAL sync_binlog=0;
it can be live changed.
sql_mode
– the default value was “NO_ENGINE_SUBSTITUTION” and now it is “ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION”, which is a pretty substantial difference. You can lose INSERTs and UPDATEs easily because a much strict mode is activated by default.
For example, with an INSERT if you do not set the value to a field, which column does not have a default value (yes, it is wrong, but it was OK before), your insert won’t be executed and you’ll get an error (or just a FALSE after execution of your query like with PHP PDO). Here is the MySQL explanation:
A value is missing when a new row to be inserted does not contain a value for a non-NULL column that has no explicit DEFAULT clause in its definition.
And more in https://dev.mysql.com/doc/refman/5.7/en/sql-mode.html#sql-mode-strict
So if you haven’t used this variable before you should put it in your my.cnf configuration for sure (in [mysqld] section):
sql_mode=NO_ENGINE_SUBSTITUTION
do not need to restart the server, just put in the my.cnf configuration file and open a MySQL root console and execute:
SET GLOBAL sql_mode='NO_ENGINE_SUBSTITUTION'