Neo4j新手从2.23迁移至3.2.14后遭遇认证错误，求解决方案

Hey there, let's work through this authentication issue you're hitting after upgrading Neo4j on your Linux 2.6.18 server. I've helped folks navigate similar migration hiccups before, so let's break down actionable fixes step by step:

1. Fix Password Hash Compatibility Issues #

Neo4j 3.x switched to a newer password hashing algorithm, which can cause conflicts when migrating from 2.x. Here's how to reset the password properly:

• Stop the Neo4j service first:

  ./neo4j stop
  

• Open your neo4j.conf file and temporarily disable authentication by setting:

  dbms.security.auth_enabled=false
  

• Start the service again:

  ./neo4j start
  

• Connect via Cypher Shell or the browser interface, then run this Cypher command to reset the password:

  ALTER USER neo4j SET PASSWORD 'neo4j'
  

• Re-enable authentication in neo4j.conf by switching the setting back to:

  dbms.security.auth_enabled=true
  

• Restart the service to apply changes:

  ./neo4j restart
  

2. Verify Critical neo4j.conf Configurations #

Double-check these settings to rule out configuration missteps:

• Ensure dbms.connectors.default_listen_address is set to your server's public IP (not localhost), otherwise remote connections will fail authentication checks.
• Confirm dbms.security.auth_provider is set to the default native—custom auth providers from 2.x might not be compatible with 3.2.14.
• Make sure there are no conflicting auth-related overrides in the config file (like old 2.x settings you forgot to remove).

3. Check Data Directory Permissions #

Neo4j 3.x enforces stricter permissions for its data directory, especially the auth file:

• Ensure the user running Neo4j has read/write access to data/dbms/auth (this file stores user credentials).
• Run these commands to fix permissions (replace /path/to/neo4j with your actual installation directory):

  chown -R neo4j:neo4j /path/to/neo4j/data
  chmod 600 /path/to/neo4j/data/dbms/auth
  

4. Clear Stale Authentication Cache #

If old auth data is lingering, try resetting from scratch:

• Stop the Neo4j service.
• Delete the data/dbms/auth file entirely.
• Start the service again—you'll be prompted to set a new initial password. Use neo4j as before and test the connection.

Bonus Check: Java Version Compatibility #

Neo4j 3.2.14 requires Java 8 (OpenJDK or Oracle JDK). Older or newer Java versions can cause unexpected authentication failures. Verify your Java version with:

java -version

内容的提问来源于stack exchange，提问作者dyhia