LDAP

The scalability of building modules is based on the number of LDAP writes resulting from profile updates and the maximum size of the LDAP database.

If the LDAP server crashes with the _db files in the /tmp directory, the files are lost when the server restarts. This improves performance but also affects availability.

If the analysis at your specific site indicates that the number of LDAP write operations is indeed a constraint, some of the possible solutions include creating building modules that replicate only a specific branch of the directory and a layer in front that directs incoming requests to the appropriate instance of portal.