Error establishing a database connection - Ubuntu WordPress on 14.04 - wordpress

Today I have started to see in my website this message "Error establishing a database connection", so I was investigating and I saw this article related and I have tried to implement it but its not working for me I still getting the same issue and I have no clue why.
Below is what I have implemented from the article:
For Apache on Ubuntu 14.04, edit the configuration file with the following command:
sudo nano /etc/apache2/sites-available/000-default.conf
Add the highlighted lines below between the tags.
Apache VirtualHost Config
<VirtualHost>
…
<files xmlrpc.php>
order allow,deny
deny from all
</files>
</VirtualHost>
Save and close this file when you are finished.
Restart the web server to enable the changes:
sudo service apache2 restart
What is weird is when I restart the droplet the website works for a couple of seconds so.. I cant figure out how to fix it.
Droplet details: 512 MB Memory / 20 GB Disk / LON1 - Ubuntu WordPress
on 14.04

The error in your logs show MySQL battling to allocate memory
Fatal error: cannot allocate memory for the buffer pool
Here's something you can do to get past it.
Add a Swap file
dd if=/dev/zero of=/swap.dat bs=1024 count=512M
mkswap /swap.dat
swapon /swap.dat
Reduce the memory footprint of MySQL
Edit /etc/my.cnf, and add the following line under the [mysqld] heading.
[mysqld]
innodb_buffer_pool_size=64M

Related

mysqld.sock in wrong directory (WSL, Ubuntu)

I'm setting up a localhost with wsl (ubuntu). While following the steps from this website, I get stuck on the wordpress setup. The install goes fine, but then creating the database gives me errors. "ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)". Checking the files, there is no /var/run folder. There is a /run/mysqld/ folder, but just not in /var. I cannot copy the /run to /var. How do I tell the setup it's in a different directory, or how do I change the /run location to be /var/run?

Error: Could not find pg_ctl executable for version 11 (PostgreSQL 11) + let's encrypt [closed]

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I have a VPS hosting with a domain redirecting to it.
I have LAMP stack for my main website using WordPress CMS.
Plus I am using Odoo as my back-end with python and PostgreSQL in a sub-domain.
Everything was working fine until I installed Certbot Let’s Encrypt to obtain an SSL certificate by following these tutorials
For My Wordpress i installed this plugin:
WP Encryption – One Click single / wildcard Free SSL certificate & force HTTPS
Which got me in a loop because it forced the https i will explain it later on
So when the plugin didn't work i searched for another way for the whole VPS with these tutorials:
How To Secure Apache with Let's Encrypt on Ubuntu 16.04
How To Secure Apache with Let's Encrypt on Ubuntu 18.04
After completing the second tutorial for ubuntu 18.04 i noticed that all my domain traffic is going to https and it got stuck in a loop saying same as i said above
"ERR_TOO_MANY_REDIRECTS which means Site redirected too many times"
and couldn't access the website front-end for the wordpress in the doamin.
Then when i applied
"Step 3 — Allowing HTTPS Through the Firewall"
my internet connection got interpreted and when i got back to the ssh session i found my self locked out of the server and did not find any way to get back in.
And when i tired to use the sub-domain that has Odoo on it i have got the same error
"ERR_TOO_MANY_REDIRECTS which means Site redirected too many times"
Until here i was hopeless and did't know what to do.
I contacted my VPS server provider and told him about what exactly happened. Then some how he managed to get me into the server again with a URL to the terminal i still couldn't access the server using ssh clients like putty.. so when i entered the server after he provided me with the URL first thing noticed is that he "rebooted the VPS" will get to this in a second.
So first thing i did was removing the wordpress plugin "WP Encryption" and update the wordpress site-url in wp_options table in mysql database because the plugin changed it from http to https so i changed it back and that solved the ERR_TOO_MANY_REDIRECTS for my wordpress website.
Then the second thing i did was disabling the ufw firewall that i enabled in the tutorial in Step 3 above.
I instantly got my connection to the server back using ssh client putty but what i have noticed again is the postgres service was inactive and went down with the reboot of the VPS. i tried to start the service but it didn't a gave me this error.
Failed to start postgresql.service: Unit postgresql.service is masked.
i searched for a solution and found these commands to unmask
sudo systemctl unmask postgresql
sudo systemctl enable postgresql
sudo systemctl restart postgresql
and then the service has started and everything sames OK when i run the status command
service postgresql status
the response is
● postgresql.service - LSB: PostgreSQL RDBMS server
Loaded: loaded (/etc/init.d/postgresql; generated)
Active: active (exited) since Thu 2020-03-26 05:54:09 UTC; 2h 22min ago
Docs: man:systemd-sysv-generator(8)
Tasks: 0 (limit: 2286)
Memory: 0B
CGroup: /system.slice/postgresql.service
but when i try to connect to postgres through the default port with odoo it says:
could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"
after many searches i made i found the posgres main cluster is also inactive or down i tried to start it with this command
pg_ctlcluster 11 main start
but i get this error
Job for postgresql#11-main.service failed because the service did not take the steps required by its unit configuration. See "systemctl status postgresql#11-main.service" and "journalctl -xe" for details.
and when i run the command as requested
systemctl status postgresql#11-main.service
i get this error
● postgresql#11-main.service - PostgreSQL Cluster 11-main Loaded: loaded (/lib/systemd/system/postgresql#.service; disabled; vendor preset: enabled) Active: failed (Result: protocol) since Thu 2020-03-26 15:22:15 UTC; 14s ago Process: 18930 ExecStart=/usr/bin/pg_ctlcluster --skip-systemctl-redirect 11-main start (code=exited, status=1/FAILURE)
alone with
systemd[1]: Starting PostgreSQL Cluster 11-main...
postgresql#11-main[18930]: Error: Could not find pg_ctl executable for version 11
systemd[1]: postgresql#11-main.service: Can't open PID file /run/postgresql/11-main.pid (yet?) after start: No such file or
systemd[1]: postgresql#11-main.service: Failed with result 'protocol'.
systemd[1]: Failed to start PostgreSQL Cluster 11-main.
I guessed Let's Encrypt added an ssl configuration to the pg_hba.conf and postgres.conf like id did with apache so i searched for them and commented the "ssl on" lines and restarted postgres service along with the main cluster but nothing happened still the the same error which is
Error: Could not find pg_ctl executable for version 11
I know i shouldn't run pg_ctl directly under Ubuntu/Debian. I must use pg_ctlcluster instead, which is installed by postgresql-common. I saw the main page documentation. But when i run "sudo pg_ctlcluster 11 main reload" command i always get the above Error telling me that he could not find pg_ctl executable
I have searched a lot for this problem but nothing worked how can i solve the pg_ctl executable in version 11 ??
Ps:
I am using Ubuntu 19.10 (GNU/Linux 5.3.0-24-generic x86_64)
Odoo 11 with postgres 11 as the database odoo can't connect to postgres as i mentioned before
edit:
Unfortunately i can't do a restore or recover the server to fix postgres package because my last backup of the server was on 19/3 and today is 26/3 i have an important data between this period
Update 27/3/2020 4:06 AM
I compared my last server backup with the production server and found a lot of postgres files missing!! like int this path /usr/lib/postgres/11/ and /etc/postgres/11/ i think postgres some how got damaged and lost some files in the reboot of the server >>> but found the data files of the database located in /var/lib/postgres/11/ <<< Can i read them in my backup server ? i will try and let you know
So finally after a hours of digging
All PostgreSQL files where damaged and missing and i lost hope of repairing them i don't know what caused that but it has a relation with the accidental reboot of the server.
So i managed to find the main cluster data file for my important database information for the production server in this path
/var/lib/postgres/11/
and i took a backup from it by zipping the whole folder using this command
zip -r main.zip main/
then i did a full purge and reinstall for postgres usuing these commands from here
apt-get --purge remove postgresql\*
to remove everything PostgreSQL from your system. Just purging the postgres package isn't enough since it's just an empty meta-package.
Once all PostgreSQL packages have been removed, run:
rm -r /etc/postgresql/
rm -r /etc/postgresql-common/
rm -r /var/lib/postgresql/
userdel -r postgres
groupdel postgres
Then i installed postgres with this command to match odoo11
sudo apt-get install postgresql libpq-dev -y
then creating the ODOO PostgreSQL User
sudo su - postgres -c "createuser -s odoo" 2> /dev/null || true
Now everything is okay odoo should work fine but you still don't have any database
So to bring back the backup from the cluster folder we took earlier we need to move the zip file to the same directory we took it from which is
/var/lib/postgres/11/
but before that you should stop postgres service
sudo systemctl stop postgresql
and make sure it has stopped
sudo systemctl status postgresql
after that rename the main cluster that postgres uses right now because its empty and we don't need it because we are replacing it with our backed up cluster
mv /var/lib/postgres/11/main /var/lib/postgres/11/main_old
then move the zip file from where you backed it up to the postgres cluster folder with this command
mv /backups/main.zip /var/lib/postgres/11/
unzip the folder in the same path by using this command
unzip -a /var/lib/postgres/11/main.zip
after unzipping the folder give the ownership to your postgres user and group
chown -R postgres:postgres main
Then you are good to go. Start Postgres service
sudo systemctl start postgresql
sudo systemctl status postgresql
and make sure you also start the main cluster service
pg_ctlcluster 11 main start
if you stopped odoo make sure to start it also
service odoo-server start
Ps: I solved ERR_TOO_MANY_REDIRECTS for the odoo sub-domain by commenting ssl configurations in my odoo.config Apache2 virtual host that lets encrypt updated before and everything got back to where left it before installing lets encrypt.
I guess i will leave it here and won't use ssl in production again till i figure out how to use it in a test server .. thanks for your time i hope my question and answer helps someone in the future
Try adding 'pg_path' in your odoo configuration file.
Like: pg_path = /path/to/postgresql/binaries
Generally '/usr/lib/posrgresql/11/bin' is the binary directory.

Ubuntu Server Nginx Error after rebooting the server

An error occurred.
Sorry, the page you are looking for is currently unavailable.
Please try again later.
If you are the system administrator of this resource then you should check the error log for details.
Faithfully yours, nginx.
I rebooted the server just before happening this using sudo reboot now since it is an ubuntu server.
I checked this .I did not understand any of it unfortunately. Also I cant access any of the pages in the specific site of mine which is showing this error.
The error.log is empty on the location /var/log/nginx
error.log.1 has some logs which happens months ago. Same for access.log.1
I am not a network guy.
sudo service nginx status
sudo service nginx start
could be that for some reason nginx not started after reboot

SELinux Policy to Allow NGINX Access to Parallels Shared Folders on Mac

I'm trying to keep SELinux enforcing but to allow NGINX to directly access shared OSX folders that are connected via Parallels Desktop.
Host system: Mac OSX 10.10
Parallels Desktop: 10
Running Virtual OS: CentOS 7 (minimal / command line)
I have the the Parallels tools installed and in CentOS I see the shared folder: /media/psf/Shared-Folder
When I set the Nginx server root to that folder I get a 403 Forbidden. I know it is a configuration parameter that needs editing because if I change SELinux to Permissive, the files are served correctly in NGINX.
When checking how the files are mounted I see this:
root root system_u:object_r:removable_t:s0 /media/psf/Shared-Folder/
I can see the 'removable_t' context - however - my issue is that I cannot seem to find a way to allow the httpd service to serve files that are mounted as removable storage.
I have tried:
chcon -R -t public_content_t /media/psf/Shared_Folder/
chcon -R -t httpd_sys_content_t /media/psf/Development-Projects/
and in all cases I get a "chcon: failed to change context of: '...': Operational not supported" error.
Checking /usr/sbin/getsebool -a | grep http I do not see any option to allow httpd to access removable storage mounts.
Last item: I do not believe I can change the way Parallels mounts the shared folders.
Question: Is there a way to keep SELinux enforcing but to allow NGINX to directly access shared OSX folders that are connected via Parallels Desktop?
What you need to do is use semanage.To get it you have to install policycoreutils-python.
The same type of question has already been asked Here. Cheers!

Internal Server Error in nginx when uploading bigger files greater than 15MB

I am using parallel plesk 11 , and there is service of nginx as reverse proxy server and i am using that , Whenever i try to upload the file size greater than 15MB it gives internal server error. I am not able to find out the problem that is causing this issue.
I am providing the php.ini settings. After checking do tell me any solution, its very urgent to know it is affecting my server services.
I am running php as fastcgi and
settings are
post_max_size 200M
upload_max_filesize 450M
memeory_limit 32M
safe_mode on
The error happened due to httpmaxrequest length error . Which was due to mod_fcgid of apache,
so i changed the fcgid.conf present in /etc/apache2/mods-available/fcgid.conf
Also this file has to be changed for proper working of uploading in parallel plesk.
MaxRequestLen in /usr/local/psa/admin/conf/templates/default/domain/domainVirtualHost.php
And After that reconfigure the domain Reconfigure domains: /usr/local/psa/admin/bin/httpdmng --reconfigure-all
Restart Both nginx and apache
service nginx restart
service apache2 restart
Than everything will work fine , Uploading this way can be done. And this is major problem which happens in ubuntu 10.10 running parallel plesk 11.

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