Neo4j Release Notes

Neo4j 1.9

The 1.9 release of Neo4j builds upon the previous 1.8 releases and brings extensive improvements in stability and performance. In addition, Neo4j 1.9 Enterprise introduces auto-clustering support, with dramatically simplified configuration and deployment for high demand production use.

Support for auto-clustering in Neo4j Enterprise, which replaces the previous Zookeeper based HA clustering, provides a streamlined deployment process and is much safer and more resilient in failure scenarios.
New neo4j-arbiter tool, which acts as a voting instance in a Neo4j cluster but does not keep a data store or handle transactions.
Addition of string manipulation, timestamp and other functions to the Cypher query language.
Improvements to memory utilization, which reduces working memory requirements and improves overall performance.
New REST endpoints for inspecting cluster status information (master, slave, etc).
Correction of several concurrency and performance issues.
Improvements to Online Backup in Neo4j Enterprise, including auto-detection of full vs incremental backup based on existing content at the backup location.
Updates to Neo4j server webadmin, including welcome pages for new users.

It is recommended to upgrade all previous Neo4j installations to this release. Neo4j 1.9 does not require any explicit upgrade to persistent stores created using Neo4j 1.7 and 1.8 installations, however current users of Neo4j Enterprise must consult the documentation and update the cluster configuration. Please see the deployment and cluster upgrade sections of the neo4j manual for more detail. Also note that Neo4j 1.9 is tested and supported with Oracle JRE 7. Users of previous Java versions should upgrade to Oracle JRE 7 when deploying Neo4j 1.9.

As part of the Neo4j 1.9 release, multiple behaviours and features of Neo4j have been declared as deprecated, in order to help users prepare for the removal of these in the next major Neo4j release. A list of deprecations can be found in the Neo4j manual.

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

Neo4j 1.8.2

The 1.8.2 release of Neo4j is a service release and includes the following corrections and improvements:

Improvements to diagnostic logging and to the reliability of embedded APIs during instance fail-over (Neo4j Enterprise in HA configuration).
Improvements to the database recovery process to avoid some scenarios that could cause the recovery after an unclean shutdown to fail.
Correction of an isolation issue that could cause the failure of some traversals in the presence of concurrent write transactions.
Allowing for a greater number of relationship types to be created within a single database. Neo4j now supports 65536 different relationship types.
Improved store locking to prevent concurrent access of the store by multiple processes.
Neo4j server will now use X-Forwarded-Host and X-Forwarded-Proto headers, if present, when generating the URIs contained in responses from the REST API.

It is recommended to upgrade all Neo4j 1.8.1 (and earlier) installations to this release, which is fully backward compatible. Please see the deployment section of the neo4j manual for more detail.

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

Neo4j 1.8.1

The 1.8.1 release of Neo4j is a service release and includes the following corrections and improvements:

Correction of several errors in the parsing and evaluation of Cypher statements.
Improvements in the memory footprint of most Cypher statements.
Correction of an error in calculating shortest paths that could occur for some graph structures.
Improvements in the diagnostic logging required for support provided by Neo Technology.

It is recommended to upgrade all Neo4j 1.8 (and earlier) installations to this release, which is fully backward compatible. Please see the deployment section of the neo4j manual for more detail.

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

Neo4j 1.8

The 1.8 release of Neo4j provides extensive improvements in stability and performance. As an incremental service release, Neo4j 1.8 builds upon the previous 1.6 and 1.7 releases and provides full backward compatibility.

This release includes the following corrections and improvements:

Correction of several concurrency issues affecting performance in multi-threaded configurations.
Correction of several concurrency issues that infrequently affect consistency of persisted data.
Optimization of high-availability (HA) protocols to increase write performance.
Support for zero-downtime rolling upgrades in HA clusters.
Improvements to transaction distribution in HA clusters, providing greater resistance to branching.
Configurable rotation of logical logs.
Support for streamed responses to REST API requests.
Support for bi-directional traversals, branch state and path expanders in the traversal framework.
Performance improvements to several graph algorithms.
Support in the Cypher language for writing graph data and updating auto-indexes (manual indexes are not supported).
Extensions to the Cypher language to allow the use of patterns as expressions and predicates.
Correction of several issues in the Cypher parser when using collections and when aggregating.
Improved error reporting in Cypher and more reliable statement parsing.
Support for explicit transactions in neo4j-shell.

It is recommended to upgrade all previous Neo4j installations to this release. Neo4j 1.8 does not require any explicit upgrade to persistent stores created using Neo4j 1.6 and 1.7 installations. Please see the deployment section of the neo4j manual for more detail.

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