Database Reference
In-Depth Information
Clients connecting to this ZooKeeper ensemble should use
zookeep-
er1:2181,zookeeper2:2181,zookeeper3:2181
as the host string in the con-
structor for the
ZooKeeper
object.
In replicated mode, there are two extra mandatory properties:
initLimit
and
syn-
cLimit
, both measured in multiples of
tickTime
.
initLimit
is the amount of time to allow for followers to connect to and sync with the
leader. If a majority of followers fail to sync within this period, the leader renounces its
leadership status and another leader election takes place. If this happens often (and you
can discover if this is the case because it is logged), it is a sign that the setting is too low.
syncLimit
is the amount of time to allow a follower to sync with the leader. If a fol-
lower fails to sync within this period, it will restart itself. Clients that were attached to this
follower will connect to another one.
These are the minimum settings needed to get up and running with a cluster of ZooKeeper
servers. There are, however, more configuration options, particularly for tuning perform-
ance, which are documented in the
ZooKeeper Administrator's Guide
.
