503 error when I edit a published post

Ok, not all plugins and themes support PHP 8.1 yet, WordPress itself just barely finished PHP 8 support.

Can you drop back to PHP 7.4.33 or PHP 8.0.29 to see if there’s any difference?

Hi @macmanx

I dropped back to 7.4.3 and the problem appeared again.

You have an awful lot of deprecated notices. Something in your system isn’t 8.1 compatible. You might be able to use debug_backtrace() to discover the root cause. Or selectively deactivate plugins and switch themes until the notices stop being logged. Or just stay with 7.4 for now.

I don’t think deprecated usage would cause 503 errors (as evidenced by 7.4 not helping any), nor should they impact the SQL issues your host thinks are at issue. They still need to be resolved if you want to use 8.1, but they are not the cause of 503 errors.

Try using the Query Monitor plugin to see if any query is taking an inordinately long time. You can’t check the query timing when you get a 503 response, but look at similar requests that do work.

503 errors typically mean either your server was overloaded, or you’ve run up against resource limitations (memory, CPU, etc.) of your hosting account. There’s usually a place in your account where you can check resource utilization. If you are maxing out available resource, you either need your site to be more efficient, or make more resource available by upgrading your hosting plan.

If the server appears to be overloaded, request that your site be moved to a different server. Worst case scenario, you may need to consider changing hosts.

What’s interesting is that this line is in your log files: BWT_IndexNow_Admin

A Google search tells me that this is the indexnow plugin ( https://github.com/microsoft/indexnow-wordpress-plugin ). Now, while it may or may not be the problem, I thought you disabled all your plugins?

You can probably ignore the deprecated lines. They’re essentially meaningless.

The HyperText Transfer Protocol (HTTP) 503 Service Unavailable server error response code indicates that the server is not ready to handle the request.

Common causes are a server that is down for maintenance or that is overloaded. This response should be used for temporary conditions and the Retry-After HTTP header should, if possible, contain the estimated time for the recovery of the service.

https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/503

This is really an issue that your host needs to investigate for you ( assuming you are on a shared / managed service )

Basically it sounds like the resources allocated to you are not up to handling the stress your install is creating.

If it is something( a plugin? ) that is really hammering the server they should be able to give you some clues. Which they have

“This process shows that the queries are incorrect or the queries made by your plugins cause an error. When the SQL service is restarted, the site broadcasts. At this point, the problem may be sql queries. In general, we recommend that you provide a review in your database queries.”

They are basically telling you that something is hammering the database and bringing it down.

WordPress is not ‘database heavy’ in its own right unless you have many thousands of post and have some database corruption such as lost indexes.

The most likely cause is a bad plugin.

But it seems you have run healthcheck plugin disabling all plugins and setting the default theme, and you still can recreate the issue. Can you confirm that is what you have done?

Is this a live site with live users? Do you have a lot of visitors in spikes?

• This reply was modified 1 year, 4 months ago by Alan Fuller.

First of all, thank you everyone.

I want to answer it first, especially since you all are asking the same question:

About 1-2 hours ago, I repeated the following two things.

I installed and activated the Health Check plugin; I did the text editing and republishing process again; and the 503 issue occurred again.

Next, I deactivated all plugins (definitely all) and the theme (switched to the twenty twenty-two theme); I did the same process again; and the 503 issue occurred again.

At the time the error occurred, no error lines were generated in any of the error/debug files in the public_html, home directory, and wp-content folder.

Throughout this issue, my hosting company was really involved and gave me the following support (they said that):

1) We did not encounter a process that received an error or stuck.
2) There is no abnormality in CPU and ram consumption on your site in general.
3) We have optimized your database.
4) We increased your PHP limits.
5) We have provided an extra resource definition in your hosting package.
6) When we provide a review, the main problem here may be that the data going to the database hangs and goes into sleep mode. This indicates that the queries are incorrect or that the queries made by your plugins are causing the error. The site starts live when the SQL service is restarted. At this point the problem may be sql queries. In general, we recommend reviewing your database queries.

@bcworkz , I did not revert to 8.1…. I used the Query Monitor plugin. There were no unusually long queries.

@alanfuller , Site is live but we have not a lot of visitors in spikes.

@otto42 , After downgrading to 7.4.3, the deprecated lines disappeared, but the problem still occurred.

This problem is intermittent, correct? Unless you can find a condition where it reliably occurs, it’s going to be very difficult to track down the problem. Is the problem related to a particular post, or does it occur randomly on any published post? Is there anything unusual about the problem posts, like are they unusually long?

This indicates … that the queries made by your plugins are causing the error.

Didn’t you say the problem occurred with no active plugins? Have you tried switching to one for the default Twenty* themes? Themes are capable of corrupting queries just as plugins could do.

If the problem occurs with no plugins and a default theme, the problem is not due to improper SQL. It’ll be something about your server configuration. Reinforced by the problem “fixing itself”. Software in this context never fixes itself. It’s almost certainly an issue with the server.

I’m sure your host will respond with something like “we cannot find any issue on our end, the problem is almost certainly software.” But literally millions of people use the exact same core software without any issues. And you’re stuck in the middle between two factions pointing to the other. For that I’m sorry. I’ve been in the same position, it’s truly aggravating. When this has happened to me, the host was willing to move the site to a different server even though they could see nothing wrong. In each case, moving did resolve the mystery problem, proving it was server related even though the cause was elusive.

@bcworkz

1) Yesterday, at my request, my hosting moved the site to another server. However, the problem arose again.
2) The problem occurs when I update (edit and republish) any published post. It does not appear when editing an unpublished post, or publishing a new post, or just editing a published post.
3) The problem occurs whenever and for which post I do the above operation.
4) Whether the post is long or short does not change the occurrence of the problem.
5) The problem also occurred when all plugins and themes were inactive, and switched to twenty twenty-two theme.

I am tired and hopeless.
I guess there’s not much left to do anymore.
Both my friends here and my hosting were very interested.
Thank you very much everyone.