Release Date: 04/14/2015

Neo4j 2.2.1 is a maintenance release, with critical improvements.

Notably, this release:

  • Resolves a number of critical issues with the 2.2 Cypher compiler, which affect validity of queries and correctness of results (#4315, #4331, #4332, #4341, #4342).
  • Deprecates the 2.0 and 2.1 Cypher compilers, which will be removed in Neo4j 2.3.
  • Provides several performance improvements related to reading and flushing data to disk.
  • Adds ability to import data in different encodings, using the import tool.
  • Ensures the import tool does not create empty array properties when there is no value for that property in the input row.
  • Resolves a critical issue that could cause the import tool to fail with an ArrayIndexOutOfBoundsException.
  • Provides several memory use and other performance improvements in the import tool.
  • Ensures client errors in the REST API always include an appropriate ClientError in the response along with a correctly identified stacktrace (#4145).
  • Resolves a rare scenario that could result in excessive memory use during a HA role switch (Neo4j Enterprise).
  • Resolves an issue affecting the use of Neo4j Browser with Internet Explorer, resulting in an incorrectly displayed Cypher query plan visualization.
  • Improves rendering of empty results in Neo4j Browser, to ensure they are clearly identified as containing no data.
  • Corrects a rare race condition that could result in successful creation of a uniqueness constraint, despite duplicate values being added during constraint creation.

All Neo4j users are recommended to upgrade to this release. Upgrading to Neo4j 2.2 (from Neo4j 2.1 or earlier) requires a migration to the on-disk store and can not be reversed. Please ensure you have a valid backup before proceeding. Production users of Neo4j 2.1, or earlier, should note that there will be configuration changes required and that applications will need to be updated to support authentication of database requests. Please see our Upgrading to Neo4j 2.2 FAQ for further details.

(Note: Neo4j 1.9 users may also upgrade directly to this release, and are recommended to do so carefully. We strongly encourage verifying the syntax and validating all responses from your Cypher scripts, REST calls, and Java code before upgrading any production system. For information about upgrading from Neo4j 1.9, please see our Upgrading to Neo4j 2 FAQ.)

For a full summary of changes in this release, please review the CHANGES.TXT file contained within the distribution.