settings in tytond.conf

[cashbook]
# enable caching of values, stores values between
# browser requests, speeds up the retrieval of data.
# default: yes
memcache = yes

# Enables synchronization of the cache between multiple
# server instances.
# default: yes
# Requires the setting :
# [cache]
# clean_timeout=0
sync = yes

# Enables caching of the cache key for currency rates.
# Reduces the time required to determine the cache
# key for currency values.
# default: yes
cache_currency = yes