George

If you are in Amazon EC2, you shall have SSH.

You may try to grep your WordPress source file to see any hints
grep -iR 'multipart/form-data' *

It seems your website is infected with Malware.

• This reply was modified 6 years, 11 months ago by George.

At the moment, as I know, most SSL providers will provide both (www and non-www) https://www.mywebsite.com and mywebsite.com version (except you are working on subdomain).

Or you may try to ask SSL provider to re-issue the SSL if possible.

Then, when the SSL cert supports both www and non-www, your WordPress can redirect visitor smoothly.

Are you running PHP 5.3 , and upgrade to latest WordPress version?
If so, try to ask web host to switch to PHP 5.6 (or 7.x)

Or try to look at web server error log for any errors.

• This reply was modified 6 years, 11 months ago by George.

Hello duongcuong96

Thanks for your reply.

I mean checksum table (to check data transfer correctness), instead of check table for healthiness.

ref.: https://dev.mysql.com/doc/refman/5.5/en/checksum-table.html

Thank you
Regards
ccto.

• This reply was modified 7 years, 2 months ago by George.

# ### Check the server active connections (check whether it relates to MySQL/MariaDB or not)
netstat -naop

# ### If it is the database server, you may check the running processes –
Goto phpMyAdmin (or mysql client in SSH console or else), and issue the SQL –
show full processlist;

from html, it may appear in your admin panel theme customize widget/secondary footer, something like that

There are some suspicious html code as below –

[ Redacted, do not post that in these forums. ]

(space is intentionally inserted for prevent execution)

You may try –
– Open Firefox
– Press Ctrl Shift del (to clear the browser cache first)
– Press Ctrl Shift i
– It shall show Developer console (default tab: Network)
– Goto your website WordPress admin panel as usual
– Goto your web page you feel slow
– In Firefox Network tab, it shall show a waterfall diagram
– You may look the loading time spent in each website element (php/css/jpg/js/etc).

(If it is the first row one (.php), probably it relates to PHP or MySQL)

It takes around 6 – 8 seconds to get the HTML source file.
# time curl https://www.heldenvandewetenschap.be/

How large is your database? I guess you might have some database performance issue.

For first query, you might have a look at

https://wordpress.stackexchange.com/questions/187612/admin-very-slow-edit-page-caused-by-core-meta-query
https://core.trac.www.ads-software.com/ticket/24498

—

For 2nd query, it seems the function is to get the most recent published post (or page), which also published in the last 2 day

PHP 7 removes the support of legacy MySQL extension, it uses MySQLi (or PDO) instead.
https://php.net/manual/en/migration70.removed-exts-sapis.php

Do you have some setting in wp-config.php ?

You may try –
https://www.recoverwp.com/tutorial-prepare-a-testing-environment-for-your-domain/

Basically, clone your website to local, then modify the host file (c:\windows\system32\drivers\etc\hosts) in your desktop computer.

You may look at apache error log for any hits first.

If you are using public shared web hosting, you may have a look at
https://www.recoverwp.com/tutorial-prepare-a-testing-environment-for-your-domain/

However, if you are using wordpress.com account, I am not sure how it works.

Hope it helps you.