Server sockets are now explicitly opened and closed for normal NTP
server, NTP broadcast and NTP peering. This will allow closing the
NTP port when not needed.
This will be used to set the kernel adjtimex() variables to allow other
applications running on the system to know if the system clock is
synchronized and the estimated error and the maximum error.
The second form configures the automatic stepping, similarly to the
makestep directive. It has two parameters, stepping threshold (in
seconds) and number of future clock updates for which will be the
threshold active. This can be used with the burst command to quickly
make a new measurement and correct the clock by stepping if needed,
without waiting for chronyd to complete the measurement and update the
clock.
The minsamples and maxsamples directives now set the default value,
which can be overriden for individual sources in the server/peer/pool
and refclock directives.
Add new functions to change source's reference ID/address and reset the
instance. Use that instead of destroying and creating a new instance
when the NTP address is changed.
A new option can be now used in the pool directive: maxsources sets the
maximum number of sources that can be used from the pool, the default
value is 4.
On start, when the pool name is resolved, chronyd will add up to 16
sources, one for each resolved address. When the number of sources from
which at least one valid reply was received reaches maxsources, the
other sources will be removed.
In addition to the quadratic function, allow configuration of the
compensation with a file containing list of (temperature, compensation)
points used for linear interpolation and extrapolation.
The new NTPv4 loop synchronization check fails as clknetsim doesn't
support IP_PKTINFO yet. Use the noselect option to prevent the server to
synchronize to the client.
When using server socket to send client requests (acquisitionport 123)
and currently not waiting for a reply, the socket check will fail for
client requests from the source.
The check needs to be moved to correctly handle the requests as from an
unknown source.
The pool directive can be used to configure chronyd for a pool of NTP
servers (e.g. pool.ntp.org). The name is expected to resolve to multiple
addresses which change over time.
On start, a source will be added for each resolved address. When a
source from the pool is unreachable or marked as falseticker, chronyd
will try to replace the source with a newly resolved address of the
pool.
The minimum interval between replacements is currently set to 244
seconds to avoid frequent DNS requests.
When adding a server from configuration file, don't give up when the
first returned address was already added for another server directive,
but try adding other addresses until one succeeds.
With the recent change allowing unreachable sources to remain selected,
offline sources will now be selectable only for some time, similarly to
online unreachable sources.
Reachability is no longer a requirement for selection. An unreachable
source can remain selected if its newest sample is not older than the
oldest sample from all reachable sources.
This is useful to prevent reselection when an accurate source uses a
very short polling interval (e.g. refclock) and is occasionally
unreachable for short periods of time.
Add new source states and rename some states so there is one state for
each reason a source can be rejected in the source selection.
This fixes reported status when sources are selectable, but the actual
selection was postponed until next update. It will also allow more
detailed reports when the cmdmon protocol is updated.
