FeatureBase Rename

As of Molecula 5.0, the core product formerly known as Pilosa will be renamed to FeatureBase. This change extends to several interfaces, so a few additional steps are required when upgrading from pre-5.0 to post-5.0. The 4.4 release includes an option to switch to the FeatureBase name early.

Previously, the Molecula release version and the Pilosa server version numbers were out of sync by one major version. For example, Molecula 4.3 includes Pilosa 3.3. Rather than advancing from Pilosa 3.x to FeatureBase 4.0, FeatureBase will skip the 4.x series, and the first major version will be 5.0. The distinct release version will no longer exist. At the same time, ingester and client versions will update to 5.0 as well.

Note that the term “FeatureBase” may be visible in some logs and error messages prior to the 5.0 release, and “Pilosa” may still be visible after the 5.0 release.

Binary name change

Starting with the 4.4 release the binary will be named featurebase rather than pilosa. Any shell scripts, service definition files, or similar references to the binary, should be updated to reflect this. During this transition, it may be helpful to define a symlink to the featurebase binary named pilosa.


Some configuration parameters previously included the word “pilosa”. For 5.0 releases, these previous parameters will continue to work, as aliases for the new names, replacing “pilosa” with “featurebase”. Starting with version 6.0, the “pilosa” aliases will no longer be available.

For future 4.x releases, FeatureBase metrics will continue to use the “pilosa” namespace. Optionally, the “featurebase” namespace can be used, by using the --future.rename configuration parameter. Starting with version 5.0, the “featurebase” namespace will be used by default.

The default data directory will switch from ~/.pilosa to /opt/molecula/featurebase, and the default node name will switch from pilosa0 to featurebase0.


In Molecula version 4.4 (Pilosa version 3.4) and later, until the next major release (FeatureBase 5.0), the optional boolean configuration parameter --future.rename is available. It has the following effects:

  • Switches the prefix that is used by environment variables for configuring FeatureBase from PILOSA to FEATUREBASE. For example, PILOSA_DATA_DIR becomes FEATUREBASE_DATA_DIR. Note that the --future.rename flag can be specified as an environment variable with PILOSA_FUTURE_RENAME, but not FEATUREBASE_FUTURE_RENAME.
  • Switches the metrics namespace (the prefix of the metric names reported by Prometheus or other metrics services) from “pilosa” to “featurebase”. For example, the Prometheus metric pilosa_maximum_shard becomes featurebase_maximum_shard.
  • Changes some log output to use the FeatureBase name instead of the Pilosa name.
  • Changes the default data directory from ~/.pilosa to /opt/molecula/featurebase
  • Changes the default node name from pilosa0 to featurebase0

Starting with FeatureBase 5.0, the featurebase versions of these will be used by default.


Several configuration parameters will be renamed, replacing “pilosa” with “featurebase”:

  • --pilosa-hosts will become --featurebase-hosts
  • --pilosa-grpc-hosts will become --featurebase-grpc-hosts
  • --assume-empty-pilosa will become --assume-empty-featurebase

In Molecula version 4.4 (ingester version 0.22.0) and later, until the next major release (FeatureBase 5.0), the featurebase versions of the flags can be enabled by setting the boolean configuration parameter --future.rename. Starting with FeatureBase 5.0, the featurebase versions of these will be used by default.

Deprecation plan

In Molecula version 4.4 (Pilosa version 3.4) and later, until the next major release (FeatureBase 5.0), the Pilosa name will be used by default, and FeatureBase can optionally be used by setting the --future.rename configuration flag.

In FeatureBase 5.x, the effects of the --future.rename flag will be applied by default, and will not be revertible. The --future.rename flag will still be present, and setting it will have no effect.

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