Impossible to modify member permissions

[SecondSight]

Hello !

I have a large number of forums and catégories on my board and,now, I can no longer modify a member group permissions : I uncheck/check the boxes for permissions in the ACP and everything seems to work fine, but it doesn't keep the changes.

 

The first time this happened to me, I was told it was likely I was running into a limitation of my server (Centos 6.6 - 64 Gb RAM - 12 processors), max_allowed_packets or max variables.

So, I changed php memory_limit value to 128M and it fixed the problem.

 

But now, using a higher value for memory_limit doesn't help fixing the problem.

 

Is there something else I can try ? (apart from removing a few categories)

 

Thank you !

 

 

 

[SecondSight]

Hello.

 

I Changed the max_input_vars value, from to 1000 to 1500 and it fixed the problem.

Do you know what is the ideal value for max_input_vars ?

 

Thank you.

[-GR-]

I don't know what the ideal setting would be but we had the same issue on one of our sites. I set ours to 2000. I would think the lower the better while still providing full functionality.

[Mark H]

That setting won't affect "performance" in any way, it's simply an upper limit to a form submission.

Whatever size is the form, the variable must be set to a high enough value to accept it.

If you have a lot of permission sets, 2000 may not be high enough. I set my own server to 5000, for example.

[SecondSight]

Thank you for your answer and pieces of advice.

[TSP]

That setting won't affect "performance" in any way, it's simply an upper limit to a form submission.

Whatever size is the form, the variable must be set to a high enough value to accept it.

If you have a lot of permission sets, 2000 may not be high enough. I set my own server to 5000, for example.

​Do you by any chance know what the setting is provided for? I mean, why is it a setting? Does it provide some level of security, performance or some other benefits to have it low?

[Mark H]

​Do you by any chance know what the setting is provided for? I mean, why is it a setting? Does it provide some level of security, performance or some other benefits to have it low?

Put as simply, and as short, as possible, when you submit a "form", that form can have many fields containing variables. In this case, those are the permissions checkboxes.

The setting is merely an upper limit on the number of those fields within the form. Any given submitted form may have far fewer than 2000 or 5000 total fields.

But there is no additional security or performance gains by setting it higher or lower.

[TSP]

I technically understand what the setting does. But since there seems to be no obvious benefits from having it low, it sounds useless to have implemented as a PHP setting. Do you agree? Or do you find there are proper use cases for it?