SysDB — System DataBase

Added checks for format strings and arguments.

Changed configure option for collectd::unixsock to --enable-collectd-unixsock.

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.

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 references by a metric).

Added support for querying time-series data through the newly introduced “time-series fetcher” plugins.

Fixed a bug that might have caused reading too much data from the connection buffer in certain situations.

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.

Documented the frontend protocol in frontend/proto.h.

Documented changes to the query language and new / updated plugins.

Documented all supported data types.