Add option to adjust the database caching size from 10000 users per directory

Summary

It would be beneficial depending on settings to allow adjusting the pre-determined cache size of 10,000 users.

Details

As per the following documentation database caching for directories is preconfigured for 10,000 users and advises not to cache if you have more than that.

Be aware of the optimal number of users. We have optimized the database caching for directories containing approximately 10 000 (ten thousand) users. If your directory is significantly larger, the new caching may not be as beneficial. For really large user bases, we recommend that you leave the caching disabled.

Notes

• For example with local groups enabled, it's not possible to disable caching so if you have more than 10,000 users you suffer extreme performance issues.
  • Eg; 80,000 users in a directory will synch up to 10,000 within minutes or an hr. The remaining 70,000, whilst eventually successful can take a full week to complete.

This makes it very hard to update user attributes such as usernames without a week long task or completely recreating their entire LDAP structure which is complicated with many directories and filers.

• Please consider adding an option to adjust the default 10,000 user database cache especially when local groups are also enabled.