def init_ha_active(datanode, cluster):
"""
Do initial HA setup on the leader.
"""
local_hostname = hookenv.local_unit().replace('/', '-')
hadoop = get_hadoop_base()
hdfs = HDFS(hadoop)
hdfs.stop_namenode()
remove_state('namenode.started')
# initial cluster is us (active) plus a standby
set_cluster_nodes([local_hostname, cluster.nodes()[0]])
update_ha_config(datanode)
hdfs.init_sharededits()
hdfs.start_namenode()
leadership.leader_set({'ha-initialized': 'true'})
set_state('namenode.started')
def check_cluster_nodes(cluster, datanode):
"""
Check to see if any of the chosen cluster nodes have gone away and
been replaced by viable replacements.
Note that we only remove a chosen node if it is no longer part of
the peer relation *and* has been replaced by a working node. This
ensures that reboots and intermittent node loses don't cause
superfluous updates.
"""
local_hostname = hookenv.local_unit().replace('/', '-')
manage_cluster_hosts(cluster) # ensure /etc/hosts is up-to-date
chosen_nodes = set(get_cluster_nodes())
current_nodes = set([local_hostname] + cluster.nodes())
remaining_nodes = chosen_nodes & current_nodes
added_nodes = current_nodes - chosen_nodes
if len(remaining_nodes) < 2 and added_nodes:
chosen_nodes = (sorted(remaining_nodes) + sorted(added_nodes))[:2]
set_cluster_nodes(chosen_nodes)
update_ha_config(datanode) # ensure new config gets written
def init_cluster_nodes():
local_hostname = hookenv.local_unit().replace('/', '-')
set_cluster_nodes([local_hostname])