processes). The default is zero, meaning replication is

disabled. WAL sender processes count towards the total number

of connections, so the parameter cannot be set higher than

<xref linkend="guc-max-connections">. This parameter can only

<xref linkend="guc-max-connections">. Abrupt streaming client

disconnection might cause an orphaned connection slot until

a timeout is reached, so this parameter should be set slightly

higher than the maximum number of expected clients so disconnected

clients can immediately reconnect. This parameter can only

be set at server start. <varname>wal_level</> must be set to

<literal>archive</> or higher to allow connections from standby

servers.