A max_input_vars variable was added in php5.3.9. If the data submitted by your post exceeds the max_input_vars value, some data will be lost.
Recently, a strange phenomenon occurred in the project. There was a large form with thousands of inputs. When submitting, I always found that the posted data was incomplete. At first, I suspected that there was a conflict in the html form name. Ruled out.
Then, I searched a lot online and found that the post_max_size and upload_max_filesize of php.ini were set to very large values, but it was useless. The client_max_body_size 500m; of nginx was set to such large values, but it was useless.
Finally I found the solution via google:
It turns out that PHP has added a variable max_input_vars since 5.3.9 to limit the number of submitted forms. I am really speechless.
This value is 1000 by default, which cannot meet the needs of more than 1000 input items, so a larger value must be added to php.ini such as:
max_input_vars = 5000, restart php after modification, and finally everything is normal!