SysDB Release Notes
=====================
The release notes contain noteworthy changes in each System DataBase (SysDB)
release, with a summary of the most important changes at the top. A complete
and very detailed list of changes can be obtained from the Git logs for each
release.
Compatibility Note:
~~~~~~~~~~~~~~~~~~~
All pre 1.0 development snapshots are not considered stable yet. That is,
all interfaces, including the plugin API, the network protocol, or the query
language, may change in an incompatible way at any time. All changes are
documented here.
About SysDB:
~~~~~~~~~~~~
“System DataBase” (SysDB) is a multi-backend system management and inventory
collection service. It stores system and inventory information about
hardware and software systems. This information is (continuously) collected
from various configurable backends (inventory services, monitoring services,
etc.) and stored in a graph-like hierarchy of generic objects. The store may
be queried through a generic interface independent of the active backends.
Object names are canonicalized before they are added to the store to ensure
a consistent view of your infrastructure.
Version 0.7.0, Release Date: 2015-02-21
---------------------------------------
This release introduces various features related to running SysDB as an
agent. Objects may now also be submitted by arbitrary applications using the
network protocol. Two new plugins are available to collect local facter fact
values and to mirror all store operations to another instance. Various fixes
and improvements have been applied to the client program (sysdb).
* build system:
- Added support for C++.
* sysdb:
- Fixed terminal resets on exit.
- Don't exit if the server closed the connection; instead reconnect
automatically on the next user input.
- Fixed string parsing: previously, quoted strings were not handled at
all and might have been terminated by an embedded semicolon.
- Also store failed commands in the history to enable history editing in
such cases.
- Improved program output: don't mix log messages with prompts after
sending a command; print log messages to the standard error channel.
- Fixed lookup of the .sysdb_history file for cases where the SysDB user
does not match the current operating system user.
* sysdbd:
- SSL options can be specified inside a block.
- Unload all plugins on exit to ensure a clean shutdown.
* client:
- Simplified RPC handling by providing a helper function.
- Added support for TCP connections using SSL/TLS and supporting, both,
IPv4 and IPv6. Remote peer verification is required for any such
connection.
- New command line flags -K, -C, and -A to specify the SSL private key,
client certificate, and CA certificates file names.
* core:
- Fully support arrays of all types.
- Fixed (implemented) reloading of time-series fetcher plugins.
- Added new callback type for "store-writers", making that part of the
store pluggable (queries are not supported).
* store:
- Added support for querying an object's siblings.
- Send all stored objects to store-writer plugins in addition to storing
them in the in-memory store.
* frontend:
- Fixed parsing of time values.
- Add support for storing hosts, services, metrics, and attributes using
the new 'STORE' command.
- Fixed handling of subsequent requests on the same connection by
avoiding unnecessary pauses of up to one second, thus, greatly speeding
up request handling.
- Added support for TCP connections supporting, both, IPv4 and IPv6.
SSL/TLS is enforced for any such connection.
- Added support for and require actual client authentication:
UNIX socket connections require peer authentication.
TCP connections require client SSL certificate authentication.
* query language:
- Added support for expressions accessing an object's siblings by using
the '.' syntax.
* JSON format:
- Fixed handling of special characters which are now being escaped.
- Include a flag indicating whether time-series data are available for a
metric.
* utils:
- os: This utility module provides some Operating System related helper
functions: access user information (current user, homedir), manage
directories (create, delete, resolve), I/O helpers (select, read,
write), networking helpers (DNS resolution).
- proto: Added support for marshaling and unmarshaling messages encoding
a datum of any type, hosts, services, metrics, and attributes.
- ssl: This new module provides convenience functions for SSL/TLS
servers, clients, and sessions using OpenSSL.
Backends:
* facter: Added a plugin collecting local facter fact values using
libcfacter (C++).
* store::network: Added a store-writer plugin sending all data to another
SysDB instance using the client library and low-level STORE commands.
Plugins:
* syslog: The log-level is now configurable using the "LogLevel" option.
Version 0.6.0, Release Date: 2014-11-17
---------------------------------------
This release focuses on a clearer query language. The underlying
architecture has been refactored to allow for more powerful and generic
expressions.
* core:
- Added support for arrays. Elements may be of any other supported
data-type but only integers, decimals, and strings are fully supported.
* store:
- Refactored matchers: all matchers now operate on one or two expressions
or other matchers, replacing the old and less flexible conditional
matchers.
- Attribute values may now be used anywhere in an expression.
- On data-type mismatch when comparing attribute values, the values will
be cast to string (previously only done for regex matches).
- Added support for querying an object's backends (array of strings).
- Added support for iterating child objects and array values.
- All matchers now return false if any operand is NULL (except for IS
NULL).
- All operations now return NULL if any operand is NULL.
- Fixed behavior of not-operators (!=, !~) and let them not match if any
of the operands is NULL.
- Add support for looking up all object types (hosts, services, metrics).
- Refactored the JSON formatter to be more flexible and powerful.
- Record parent objects for each stored object.
* frontend:
- Added a separate parser mode for expressions.
- Added a new queryable field 'name' to be used in place of the rather
magical keyword 'host' when looking up hosts.
- Improved error reporting in the parser and the (newly introduced)
analyzer.
- Apply filters to hosts in the FETCH command.
* query language:
- All operators may now be used in all places if the involved data-types
support the respective operation. For example, regular expressions may
be used to match any value. Non-string values are cast to strings for
that purpose. IS NULL / IS NOT NULL may be applied to arbitrary
expressions.
- Introduced the 'IN' operator to check if a value or an array of values
is included in an array.
- Added support for arrays: [,,...]
- Added support for string and array concatenation using the '||'
operator.
- Attribute names have to be strings instead of identifiers now.
- Access object fields using '' rather than '.'.
- Let the LOOKUP and FETCH commands support services and metrics.
- Introduced 'FETCH service|metric . ' replaces
'MATCHING service|metric|attribute ' expressions.
Version 0.5.0, Release Date: 2014-10-06
---------------------------------------
This release focuses on simplifications and more flexibility in the frontend
and the query language. Most of those changes are not backward-compatible
but easy client implementations.
* sysdb:
- Include priority when printing log messages.
- Fixed handling of empty queries.
* store:
- When serializing the entire store (LIST command), return an array of
host objects (rather than wrapping it into another object).
- Fixed JSON format of time-series data.
- Fixed error checks of invalid compare expressions and reject them.
- Fixed lookups by back-end name.
- Added support for comparing attributes with different types by
comparing their string values.
* frontend:
- Clarified details about asynchronous messages and authentication
options and made client implementation more robust.
- Introduced a new message type encoding the JSON serialized response of
a query and its data type.
- Include the priority in log messages.
- Include object types in FETCH, LIST, and LOOKUP messages.
- Added support for including services and metrics in LIST responses and
skip hosts without the respective children.
* query language:
- Added support for services and metrics to LIST command.
- Changed syntax for attribute lookup to 'attributes[]'.
- Changed syntax for accessing queryable fields to '.'.
* utils:
- strbuf: Improved memory management.
Version 0.4.0, Release Date: 2014-09-01
---------------------------------------
This release features support for metrics and transparent access to a
backend's time-series data. Some backward-incompatible changes were applied
to some query commands for more consistency.
* build system:
- Added checks for format strings and arguments.
- Changed configure option for collectd::unixsock to
--enable-collectd-unixsock.
* core:
- Added support for “metric” objects which may be assigned to a host.
- Introduced support for handling time-series data: added new data
structures describing time-series data and a new type of plugins called
“time-series fetchers” which are used to access time-series
information.
* store:
- Fixed a memory leak.
- Apply (very) simple optimizations to lookup expressions.
- Added support for metrics and their “data-stores” (describing how to
access the actual data referenced by a metric).
- Added support for querying time-series data through the newly
introduced “time-series fetcher” plugins.
* frontend:
- Fixed a bug that might have caused reading too much data from the
connection buffer in certain situations.
* query language:
- The ‘MATCHING’ clause is now optional in ‘LOOKUP’ queries.
- The ‘LIST’ and ‘FETCH’ commands support ‘FILTER’ clauses as well.
- ‘LIST’ / ‘FETCH’ were changed to ‘LIST hosts’ / ‘FETCH host’.
- Added the ‘TIMESERIES’ command to query arbitrary time-series which
fetches time-series data from a backend's data-store for a given period
of time.
- Added support for date/time values.
- Added support for single quotes in string values: two adjacent single
quotes may be used to specify a single quote.
* documentation:
- Documented the frontend protocol in frontend/proto.h.
- Documented changes to the query language and new / updated plugins.
- Documented all supported data types.
Backends:
* collectd::unixsock:
- The plugin now uses metrics in place of services.
- New config options ‘TimeseriesBackend’ and ‘TimeseriesBaseURL’ to
specify access to time-series, currently limited to ‘rrdtool’ and
‘rrdcached’ access.
Plugins:
* timeseries::rrdtool:
- New plugin adding support to fetch time-series from local RRD files.
- Supports flushing of values in RRDCacheD.
Version 0.3.0, Release Date: 2014-08-01
---------------------------------------
This release includes major enhancements and new features in the SysDB store
which is the core of the database. Most notably, complex expressions are now
supported when looking up information and filters may be used to preselect
the information to be returned. Some backward-incompatible changes were
introduced in the query language to avoid potentially confusing semantics.
* sysdb: Fixed non-interactive mode when using libedit.
* core:
- Fixed weird behavior when collector callbacks were registered without
any plugin context information (as it would, e.g., happen when using
LoadPlugin instead of LoadBackend in sysdbd).
* store:
- Introduced service attributes -- similar to host attributes but
assigned to a service object.
- Don't log “value too old” messages if an updated object uses the same
timestamp as the old object.
- Switched from linked-lists to AVL trees for storing all object types to
reduce lookup times from O(n) to O(log n).
- Added infrastructure for handling and evaluating arithmetic
expressions and filters (see also the changes to the query language
below).
- Export various fields describing base attributes of all stored object
types: last_update, age, interval, and backend. These fields may be
used when querying the store.
* frontend: Include new service attributes in JSON output.
* query language:
- Added support for ‘IS NULL’ attribute checks matching on non-existent
attributes.
- Changed ‘LOOKUP ... WHERE’ queries to ‘LOOKUP ... MATCHING’ to avoid
confusion with SQL semantics.
- Switched from ‘.name’ to ‘’ in MATCHING clauses, thus, no
longer shadowing attributes called “name”.
- Added support for arithmetic expressions in places that used simple
data values before. Arithmetic expressions support addition,
subtraction, multiplication, division, modulo, and concatenation
operations. The expressions may be based on constant values or
queryable fields of the stored objects (specified as ‘:last_update’,
‘:age’, ‘:interval’, and ‘:backend’).
- Added ‘FILTER’ support to ‘LOOKUP’ queries. Filters are conditional
expressions which may optionally be used to limit the query and the
result to object (of any type) matching the filter condition.
- Added support to specify date and time values.
* utils:
- avltree: Added an AVL tree (self-balancing binary tree) implementation.
* documentation: Added documentation for the new query language features.
* testing: Run all unit tests through valgrind by default (if available).
Backends:
* collectd::unixsock:
- Added support for spaces in identifiers.
- Store plugin identifier (host, plugin, plugin_instance, type,
type_instance) as service attributes.
Version 0.2.0, Release Date: 2014-07-02
---------------------------------------
This is another development snapshot of SysDB. The main focus of this
release is on stabilizing existing features and extending the query
infrastructure to support all attribute types and further operators.
* build system: Fixed linking of sysdbd to include *all* necessary object
files. This bug caused some plugins to be un-loadable.
* sysdbd: Fixed shutdown process in case of errors.
* sysdb: Fixed a bug causing some server replies to be ignored when exiting
from the client.
* core:
- Always log to the standard output stream if no user-provided logging
callbacks had been specified. Previously this was disabled after
enabling logging to clients in the frontend.
- Simplified plugin naming information and determine configuration
callback names automatically to ensure better consistency.
* store:
- Simplified internal data management.
- Store the list of backends along with each stored object which provide
the respective object.
* frontend:
- Simplified and improved the internal architecture matching / looking up
objects.
- Fixed parser to correctly reject invalid object types.
- Automatically create the base directory of a listening UNIX socket.
* query language: Added support for numeric constants and added operators
for less and greater than or equal attribute comparison.
* documentation: Added missing files to the distribution tarball.
Plugins:
* syslog: Don't log debug messages to syslog.
Version 0.1.0, Release Date: 2014-06-01
---------------------------------------
This is the initial release of SysDB. It provides the following core
features:
* sysdb: A terminal-based, interactive client program. Supports
line-editing and history based on libreadline or libedit and uses an
asynchronous, event-driven architecture to handle user input and server
replies simultaneously.
* sysdbd: The database backend service configurable through a configuration
file. The daemon supports online reconfiguration.
* core: Flexible, multi-threaded core architecture providing a configurable
plugin infrastructure for querying external data-sources and extending
core functionality. The following plugin types are supported:
- data collection
- hostname canonicalization
- logging
* store: Central, in-memory object store managing host and service objects
and their attributes. Host names may be canonicalized through respective
plugins. Each object is automatically attributed with last update and
interval information using nano-seconds resolution. Attributes may have
various types (integer, decimal, string, date-time, binary).
* frontend: The frontend handling client connections uses a multi-threaded,
asynchronous, event-driven architecture capable of handling multiple
listen addresses.
* query language: The store may be queried using the ‘LIST’, ‘LOOKUP’, and
‘FETCH’ commands returning JSON formatted objects.
* utils: A rich set of abstract data-types and utility functions for
internal use:
- generic channels for asynchronous, multi-threaded I/O
- DBI wrapper to ease common database access operations
- thread-aware error handling and reporting
- doubly linked-lists
- dynamic sized memory buffers supporting formatted strings and binary
data
- UNIX socket client implementation
* documentation: Full documentation for the tools, all plugins, and the
query language provided as manpages and HTML pages.
* testing: Unit and integration tests exist for most parts except plugins
covering 77% of all functions. Valgrind and Clang's address sanitzer are
used to detect memory leaks and programming errors.
The following plugins are shipped with this version of SysDB:
Backends:
* collectd::unixsock: Query collectd through its ‘unixsock’ interface
* mk-livestatus: Query arbitrary (monitoring) systems using the Check_MK
Livestatus interface.
* puppet::store-configs: Query Puppet through its “stored configuration”
database.
Plugins:
* cname::dns: Canonicalize hostnames by querying DNS information.
* syslog: Send log messages to the system log service.