Doclists and hitlists components can be also accessed using memory-mapping (like attributes are) instead of seek+read. Choosing the access mode can be made with access_doclists and access_hitlists directives.
New directives access_plain_attrs and access_blob_attrs replace the functionality provided by ondisk_attrs and mlock. The new directives allow more scenarios of how types of attributes can be loaded and locked or not in the memory.
The access_* directives can be set globally in searchd section of configuration or per index in index configuration section. For more details about the new access directives check Accessing index files.
New directive server_id used as seed for node UUID inside a replication cluster.
/search endpoint was removed .
A number of fixes are included in this release, to highlight a few:
For a full report please consult the Release note.