The hadoop.security.auth_to_local under Advanced core-site.xml in HDFS service can be modified to remove spaces in user names. This translation rule is a modification of the default rule
The default rule has a line which removes the domain name
In order to translate the user name with Spaces "John Doe@MYDOMAIN.COM" to "John_Doe" The following rule can be used
RULE:[1:$1](.* .*)s/ /_/g/L
The first rule replaces the Space with the Underscore while retaining the MYDOMAIN.COM and allows second rule also to be respected. This results in successful replacement of usernames with spaces to underscores.