Ranger usersync cookie default duration for sync

Hi!

At this moment we cant initial sync out of the box our LDAP with 10k+ users & groups.

It's because sync works as three steps:

1) Sync groups

2) Sync users

3) Map users&groups as one request and send it to rangeradmin

From time to time our third step on initial sync generate this single request for a long time

It can be easily three or four hours.

Acrossing this timegate we have an error with timeout usersync cookie (that by default is 60 minutes) and failed 3rd step.

The workaround - is 

ranger_admin_directory/ews/webapp/WEB-INF/web.xml
change 
default 
<session-timeout>60</session-timeout> 
to just in case
<session-timeout>1440</session-timeout>

BUT im was really frustrated with this behavior whan faced it first time, and i want to have a mechanism to split mapping step for a smaller part, and update cookie from time to time. 

Thank you.