From: Marcin Siodelski Date: Mon, 20 Sep 2021 20:09:49 +0000 (+0200) Subject: [#1959] ARM parahraph about unsent-update-count X-Git-Tag: Kea-2.0.0~74 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d639943bd9811ab81473374bad22b05264447e4d;p=thirdparty%2Fkea.git [#1959] ARM parahraph about unsent-update-count --- diff --git a/doc/sphinx/arm/hooks-ha.rst b/doc/sphinx/arm/hooks-ha.rst index e3c1995a03..9f3d6ed9b5 100644 --- a/doc/sphinx/arm/hooks-ha.rst +++ b/doc/sphinx/arm/hooks-ha.rst @@ -1927,9 +1927,19 @@ to establish TCP connection to the Control Agent or the Control Agent reports issues with communication with the DHCP server, it is very likely that the server is not running. -The ``date-time`` parameter conveys the server's notion of time. The -``unsent-update-count`` is used internally by the partner receiving the heartbeat -response to determine whether it should synchronize its lease database. +The ``date-time`` parameter conveys the server's notion of time. + +The ``unsent-update-count`` value is incremented by the partner sending the heartbeat +response when it cannot send the lease update. Suppose it is a result of the +temporary communication interruption. In that case, the partner receiving the +heartbeat response tracks the value changes and can determine whether there are +any new lease updates that it did not receive. When the communication is +re-established, the server uses this value to decide whether or not it should +synchronize its lease database. The value is set to 0 when the server is started. +It is never reset to 0 during the server operation, even after the partner +synchronizes the database. It is a cumulative count of all unsent lease updates +since the server boot. A non-zero value itself is not an indication of any present +issues with lease updates. Constantly incrementing value is. The typical response returned by one of the servers when both servers are operational is: