In addition to the ltcluster configuration settings, parameters in the
  conninfo string influence how ltcluster makes a network connection to
  LightDB. In particular, if another server in the replication cluster
  is unreachable at network level, system network settings will influence
  the length of time it takes to determine that the connection is not possible.
 
  In particular explicitly setting a parameter for connect_timeout
  should be considered; the effective minimum value of 2
  (seconds) will ensure that a connection failure at network level is reported
  as soon as possible, otherwise depending on the system settings (e.g.
  tcp_syn_retries in Linux) a delay of a minute or more
  is possible.
 
  For further details on conninfo network connection
  parameters, see the
  LightDB documentation.