Category: 标准
IETF YANG工具
YANG Schema Mount
https://datatracker.ietf.org/doc/draft-ietf-netmod-schema-mount/?include_text=1
augment类似于继承,schema mount类似于组合,接口。
为什么说多用组合,少用继承?
YANG Notification
Traditional approaches to remote network state visibility rely
heavily on polling. ?With polling, data is periodically explicitly
retrieved by a client from a server to stay up-to-date.
There are various issues associated with polling-based management:
o ?It introduces additional load on network, devices, and
applications. ?Each polling cycle requires a separate yet arguably
redundant request that results in an interrupt, requires parsing,
consumes bandwidth.
Clemm, et al. ? ? ? ? ? Expires December 17, 2016 ? ? ? ? ? ? ? [Page 3]
Internet-Draft ? ? ? ? ? ? ? ? ?YANG-Push ? ? ? ? ? ? ? ? ? ? ?June 2016
o ?It lacks robustness. ?Polling cycles may be missed, requests may
be delayed or get lost, often particularly in cases when the
network is under stress and hence exactly when the need for the
data is the greatest.
o ?Data may be difficult to calibrate and compare. ?Polling requests
may undergo slight fluctuations, resulting in intervals of
different lengths which makes data hard to compare. ?Likewise,
pollers may have difficulty issuing requests that reach all
devices at the same time, resulting in offset polling intervals
which again make data hard to compare.
Yang
YANG [RFC6020] was originally designed for the Netconf protocol
[RFC6241], which originally put most emphasis on configuration.
However, YANG is not restricted to configuration data. ?YANG
datastores, i.e. datastores that contain data modeled according using
YANG, can contain configuration as well as operational data. ?It is
therefore reasonable to expect that data in YANG datastores will
increasingly be used to support applications that are not focused on
managing configurations but that are, for example, related to service
assurance.
Service assurance applications typically involve monitoring
operational state of networks and devices; of particular interest are
changes that this data undergoes over time. ?Likewise, there are
applications in which data and objects from one datastore need to be
made available both to applications in other systems and to remote
datastores [I-D.voit-netmod-yang-mount-requirements]
[I-D.clemm-netmod-mount]. ?This requires mechanisms that allow remote
systems to become quickly aware of any updates to allow to validate
and maintain cross-network integrity and consistency.
Traditional approaches to remote network state visibility rely
heavily on polling. ?With polling, data is periodically explicitly
retrieved by a client from a server to stay up-to-date.