Network Administration Visualized 4.0b2

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 Network Administration Visualized release notes
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Please report bugs at https://bugs.launchpad.net/nav/+filebug . To browse
existing bug reports, go to https://bugs.launchpad.net/nav .

If you are upgrading from versions of NAV older than 3.7, please refer to the
release notes of the in-between versions before reading any further.

Known problems
==============

The recommended SNMP library for use with ipdevpoll is `pynetsnmp`. If you
choose to go with the original TwistedSNMP, the latest version (0.3.13)
contains a bug that manifests in table retrieval operations. Timeouts and
retries aren't handled properly, and this may cause slow or otherwise busy
devices to be bombarded with requests from NAV. The `contrib/patches`
directory contains a patch for TwistedSNMP that solves this problem. The
patch has been submitted upstream, but not yet accepted into a new release.

NAV 4.0
========

To see the overview of scheduled features and reported bugs on the 4.0 series
of NAV, please go to https://launchpad.net/nav/4.0 .

Dependency changes
------------------

New dependencies:

- Graphite_
- Sass_ >= 3.2.12 (only required at build time)
- The Python module :mod:`django-crispy-forms` == 1.3.2
- the Python module :mod:`crispy-forms-foundation` == 0.2.3

Changed version requirements:

- `Python` >= 2.7.0

Removed dependencies:

- Cricket
- rrdtool

.. _Graphite: http://graphite.wikidot.com/
.. _Sass: http://sass-lang.com/

Major changes to statistics collection
--------------------------------------

NAV 4.0 ditches Cricket for collection and presentation of time-series data.
Cricket is great for manually maintaining large configurations, but becomes
quite inflexible when integrating with a tool like NAV. Also, Cricket has not
been actively developed since 2004.

Collection of time-series data via SNMP has become the responsibility of NAV's
existing SNMP collector engine, `ipdevpoll`, implemented as new plugins and
job configurations.

RRDtool has also been ditched in favor of Graphite_, a more flexible and
scalable system for storage of time-series data. Graphite provides a networked
service for receiving *"metrics"*, meaning it can be installed on a separate
server, if desirable. It will even scale horizontally, if needed.

The parts of NAV that collect or otherwise produce time-series data, such as
values collected via SNMP, ping roundtrip times or ipdevpoll job performance
metrics, will now send these to a configured Carbon backend (Graphite's
metric-receiving daemon).

Due to this extensive change, the threshold manager interface and the threshold
monitor have been rewritten from scratch. The new threshold monitoring system
uses *"threshold rules"*, which leverage functionality built-in to Graphite.
It is also essentially independent of NAV, which means it can also monitor
thresholds for data that was put into Graphite by 3rd party software.

Migrating existing data
-----------------------

Existing threshold values for RRD-based data sources cannot be consistently
migrated to the new threshold rule system, so you will need to configure your
threshold rules from scratch.

We do provide a program for migrating time-series data stored in RRD files
into Graphite, which will enable you to keep old data when upgrading from an
older NAV version. Usage and limitations of this program is documented in a
separate howto guide: :doc:`/howto/migrate-rrd-to-graphite`.

.. note:: If you wish to migrate time-series data, please read :doc:`the guide
          </howto/migrate-rrd-to-graphite>` **before** starting NAV 4.