def handle_peers()

in bigtop-packages/src/charm/hbase/layer-hbase/reactive/hbase.py [0:0]

• 34 lines of code
• 6 McCabe index (conditional complexity)

def handle_peers():
    '''
    We use HBase peers to keep track of the RegionServer IP addresses in a
    cluster. Use get_nodes() from the appropriate peer relation to retrieve
    a list of peer tuples, e.g.:
        [('hbase/0', '172.31.5.161'), ('hbase/2', '172.31.5.11')]

    Depending on the state, this handler will add or remove peer IP addresses
    from the regionservers config file.
    '''
    if is_state('hbpeer.departed'):
        hbpeer = RelationBase.from_state('hbpeer.departed')
        is_departing = True
        message = 'removing hbase peer(s)'
    else:
        hbpeer = RelationBase.from_state('hbpeer.joined')
        is_departing = False
        message = 'adding hbase peer(s)'

    # Make sure we have a valid relation object
    if hbpeer:
        nodes = hbpeer.get_nodes()
    else:
        hookenv.log('Ignoring unknown HBase peer state')
        return

    hookenv.status_set('maintenance', message)
    hbase = HBase()
    ip_addrs = [node[1] for node in nodes]
    hookenv.log('{}: {}'.format(message, ip_addrs))
    hbase.update_regionservers(ip_addrs, remove=is_departing)

    # NB: the rs conf file will always change when handling peer updates, but
    # we still include this condition to keep the files_changed kv current.
    if any_file_changed(['/etc/hbase/conf/regionservers']):
        hbase.restart()

    # Dismiss appropriate state now that we've handled the peer
    if is_departing:
        hbpeer.dismiss_departed()
    else:
        hbpeer.dismiss_joined()
    report_status()