No request delivery notification has been received from LSAPI application, possible dead lock

[Andriusa]

Hello,

I have a problem with this error: No request delivery notification has been received from LSAPI application, possible dead lock.

I have wordpress website and sometimes it just gets stuck.

Error.log:

2024-07-16 11:06:49.201257 [INFO] [850] [90.131.35.116:9129-Q:FEBE0F664A7FB194-32#wordpress] Connection idle time too long: 301 while in state: 13 watching for event: 270344, close!
2024-07-16 11:06:49.201303 [INFO] [850] [90.131.35.116:9129-Q:FEBE0F664A7FB194-32] Content len: 0, request line: ‘GET /favicon.ico HTTP/1.1’
2024-07-16 11:06:49.201307 [INFO] [850] [90.131.35.116:9129-Q:FEBE0F664A7FB194-32] Redirect: #1, URL: /index.php
2024-07-16 11:06:49.201312 [INFO] [850] [90.131.35.116:9129-Q:FEBE0F664A7FB194-32#wordpress] HttpExtConnector state: 40, request body sent: 0, response body size: 0, response body sent:0, left in buffer: 0, attempts: 0.
2024-07-16 11:06:49.201314 [INFO] [850] [90.131.35.116:9129-Q:FEBE0F664A7FB194-32#wordpress] External processor is not available.
2024-07-16 11:06:50.019980 [NOTICE] [853] [88.118.71.168:50492-Q:4118AB31BECF9349-360#wordpress] No request delivery notification has been received from LSAPI application, possible dead lock.
2024-07-16 11:06:50.024599 [NOTICE] [851] [78.61.114.179:59558-Q:C2D55509F584D0F9-8#wordpress] No request delivery notification has been received from LSAPI application, possible dead lock.
2024-07-16 11:06:50.024729 [NOTICE] [851] [217.147.47.212:49525-Q:CA72DF8DF256F1C4-16#wordpress] No request delivery notification has been received from LSAPI application, possible dead lock.
2024-07-16 11:06:52.008569 [NOTICE] [851] [217.147.47.212:49525-Q:CA72DF8DF256F1C4-20#wordpress] No request delivery notification has been received from LSAPI application, possible dead lock.
2024-07-16 11:06:52.008633 [NOTICE] [851] [188.69.43.104:8415-Q:2D95002B815943EF-20#wordpress] No request delivery notification has been received from LSAPI application, possible dead lock.
2024-07-16 11:06:52.017226 [NOTICE] [853] [85.232.129.9:60600:HTTP2-5#wordpress] ExtConn timed out while processing.

 

[Cold-Egg]

Hi @Andriusa
Please check a similar post here.

 

[Andriusa]

Hi @Andriusa
Please check a similar post here.

I checked this post but it does not help. My server crashes from time to time and I get error: Error establishing a database connection.

Tried to increas LSPI children to 200, but it crashes even after that. For that moment I dont know what I can try more

 

[mister_x]

In my experience, the "possible dead lock" is caused by low server resources. It might not be your case but please share some hardware info. Also, when does it happen? How many websites are you hosting on the machine?

 

[Andriusa]

In my experience, the "possible dead lock" is caused by low server resources. It might not be your case but please share some hardware info. Also, when does it happen? How many websites are you hosting on the machine?

It happens randomly. My website can work for a few days ok and suddenly it just crashes. I see that my VPS memory goes up to ~100% and I get Error establishing a database connection when I try to visit my website. When I restart mariadb it works again.

My VPS server hardware info: 8 GB Memory / 4 Intel vCPUs / 240 GB Disk

I host 1 website which gets up to 500k visits per month.

 

[mister_x]

Considering you are using WordPress, we can rule out bad code.
Despite 4 cores and 8 GB RAM might look good, 500k/m visitors is still a significant load because WordPress is dynamically generating the pages.
Are you leveraging the load using cache plugins and CDN?

In my advice, I would go for a better machine, a multicore dedicated server with plenty of RAM would be the best action for that traffic.

 

[Andriusa]

Considering you are using WordPress, we can rule out bad code.
Despite 4 cores and 8 GB RAM might look good, 500k/m visitors is still a significant load because WordPress is dynamically generating the pages.
Are you leveraging the load using cache plugins and CDN?

In my advice, I would go for a better machine, a multicore dedicated server with plenty of RAM would be the best action for that traffic.

I am using litespeedcache plugin but I dont use CDN. Usualy my website uses like ~20~50% of server resources and before migrating from apache to openlitespeed everything was ok with that.

Yesterday I tried to increas LSPI CHILDREN to 300 I dont know but maybe it will help somehow..

 

[mister_x]

In my advice, a constant 20%-50% is a lot.
Note that Litespeed is faster than Apache because it also uses a different multithreaded task handling. I believe this makes it more sensitive to available server resources.

 

[mister_x]

You could also try setting the CPU Affinity to 1. Might improve the overall handling of the processes.

 

[Andriusa]

You could also try setting the CPU Affinity to 1. Might improve the overall handling of the processes.

Thank you for you replies and help. I saw a recommendation in one forum about CPU Affinity changing to 1 but I could find where I can change it. Thank you for screenshot. Now I changed it to 1. I will keep this post updated if it will help or no.