curr_connections does a counter underflow when no of connection from client is more than the no of conn specified in membase

start membase with 80 connection limit
/opt/membase/bin/memcached/memcached -d -p 11211 -u nobody -c 80 -E /opt/membase/bin/ep_engine/ep.so -r -l 0.0.0.0 -e dbname=/db/membase/default;min_data_age=0;queue_age_cap=900;max_size=10737418240;initfile=/tmp/init.sql;ht_size=12582917;max_txn_size=250000 -v

start memslap with 100+ connections:
./memslap -s server_name -F config_file_3.5k -T 1 -c 100 --execute_number=300

Observed: curr_connections does a counter underflow 4294967289