The configuration file can be found in /data/dalmatinerdb/etc/ddb.conf. Most configuration variables are described in the file itself so this section will only cover the most important variables.

Configuration File

Many of the configuration settings are based on riak_core and can be looked up in basho's excellent documentation for riak_kv.

`points_per_file`

DalmatinerDB stores metrics in a flat file, the points_per_file setting defines how many data points each file holds. The time that fits in a file depends on the resolution of the bucket, by default this is set up 604800 which means one week of data at one second resolution.

This setting applies on a bucket level, however it can not be changed after the bucket was created!

`cache_points`

DalmatinerDB keeps a write cache, this is not related to the bucket resolution but only the number of points kept in the write cache. Caches are only flushed once they are full or when a read requires them to be written for consistency.

This setting exists on a global level and can not be changed during runtime.

`lifetime`

The lifetime defines when metric points are garbage collected. This is a default setting that can be overwritten on a per bucket level. It needs to be either a positive integer or the atom infinity. When an integer is provided it states to the number of points not a timeframe as that would differ based on the resolution of the bucket.

When configured with ddb-admin timeframes can be provided and bucket resolution will be taken into account.

`vacuum_interval`

Defines how often a vacuum is run, each run a vnode is picked to run the cleanup, that way a vacuum process won't hold the whole cluster.