We use LDAP autentication, mysql DB server, imapproxy, do you think we will have to change something in the configuration files moving from a version to another one ?
No one here can answer that with any certainty since we don't know your config.
I understand that you have a lot of concerns because you are making such a big jump, your current version is way out of date so its a bit scary. Do you have an test environment you can run the update in first? If you are using only the skins and plugins distributed with Roundcube then it should be pretty smooth.
Ok i moved from v1.0.x to v1.0.12 and then i moved from v1.0.12 to v1.1.12, i had to change the captcha plugin because the old one drcaptcha was not available anymore and outdated i suppose, so i change it with rcguard plugin, i configured it to use recaptcha v2 from google and now it seems to work, i can't get the pictures but only the tick box, but some other user told me he had the pictures, so maybe it is working i suppose.
Other strange thing is that it would use the new table rcguard but it is empty, always, anyway i enabled the plugin always, so attempts set to 0, maybe with this value it doesn't need to use the DB.
I have only the capthca and the keyboard_shortcuts (i hope this will work with newer release of roundcube) plugins installed so i suppose i will not have too problems moving forward again.
Are there some settings that will be need to be removed moving to newer versions ?
For sure there will have been some changes to the default config in all this time, if you need to change anything though I can't answer because I don't know your config. Your config.inc.php file should only contain things you have changed from the defaults so if you review those configs against the current defaults.inc.php you should be fine. Any breaking changes to config should be mentioned in the release notes of the various versions - there was a problem with 1.4 where the info only went into the release notes with 1.4.1.
In general though I think Roundcube has good backwards compatibility.
Ok no problem i will switch to v1.2.9 then v1.3.10, then if all works i will move to v1.4.3, i always will use the latest version of each main release.
Are there any tweaks (memcache or other software to use) to speed up the roundcube clients experience ?
There are a few tips here https://github.com/roundcube/roundcubemail/wiki/Configuration:-Load-balanced-Setup
Ok i read that document and i have already this kind of setup, so i don't need to upgrade nothing about it
But now i have a new question:
I have found that i can have two mysql user account, one for WRITE and one for READ using the
$config['db_dsnw'] = ''; for WRITE operations
$config['db_dsnr'] = ''; for READ operations
and then
$config['db_dsnw_noread'] = true;
i set it now but how i can check if it is working or not ?
in the documentation it tell for the db_dsnr config
// Database DSN for read-only operations (if empty write database will be used)
// useful for database replication
and for the db_dsnw_noread config
// Disable the use of already established dsnw connections for subsequent reads
Is true the right value if i want to use the READ account for read operations also if the WRITE account was used before ?
Thanks again
Claudio