CPU spikes

[zoom23]

Hi,
I have a VPS in DigitalOcean on which i've installed Sentora.I am getting strange CPU spikes, and after that my Sentora panel and the websites get an error:can't connect to the database.
I reboot the vps and everything is fine, but it happened already 3 times.

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in my syslog file i see this
Apr 16 07:03:41 panel suhosin[8647]: ALERT - script tried to increase memory_limit to 94371840 bytes which is above the allowed value (attacker '37.187.162.183', file '/var/sentora/hostdata/zoom23/public_html/sofiapress_com/wp-includes/default-constants.php', line 52)
in php.ini i have set the:
memory_limit=80M
post_max_size=28M
upload_max_filesize=28M

[Me.B]

Seem the WP plugin is using too much ram and so blow out your website.

Do you have enough ram or only the basic 512MB?

M B

[zoom23]

My server has 1GB RAM.I have increased the memory limit of the server to 128mb.On the website i have a memory plugin which indicates memory usage of 38mb.Is it possible this one website to bring my whole server down?When this problem occurs i see a sudden spike in CPU usage and then it gives the error-Can't connect to the database and i have to reboot the server.Here are the graphs from DigitalOcean

[Account_Own]

My server has 1GB RAM.I have increased the memory limit of the server to 128mb.On the website i have a memory plugin which indicates memory usage of 38mb.Is it possible this one website to bring my whole server down?When this problem occurs i see a sudden spike in CPU usage and then it gives the error-Can't connect to the database and i have to reboot the server.Here are the graphs from DigitalOcean

It may be a ddos attack..??? What they said you there in DigitalOcean regarding this..???

[Me.B]

A plugin or any badly written code can take down bigger server without so many requests.

Use P3 profiler:

https://wordpress.org/plugins/p3-profiler/

And check plugins load.

My advice always avoid bloated plugins and only use what you really need.

M B