Configuring Neo4j buffer size

Introduction

In some situations you may face an error when attempting to import applications into CAST Imaging (see Export and import the Application data) as follows:

ERROR Import: error while importing objects, aborting import error=objects: failed to run queries to import objects: run: error running Creation of Object to Property Links cypher for APPLICATION_NAME:

exec: unable to run cypher query: Neo4jError: Neo.DatabaseError.Statement.ExecutionFailed (Tried to read a field larger than buffer size 10000000.

A common cause of this is that a field has an unterminated quote and so will try to seek until the next quote, which ever line it may be on. This should not happen if multi-line fields are disabled, given that the fields contains no new-line characters. This field started at /var/lib/neo4j/import/csv/neo4j/APPLICATION_NAME_is_cfg_object_properties.csv:6891)

This error indicates that a property in the exported data has exceeded the default Neo4j maximum of 10MB - and that the application data failed to be imported correctly.

Update process

To resolve this issue, edit the neo4j.conf file located here:

Microsoft Windows traditional installer:
%APPDATA%\CAST\ImagingSystem\neo4j\neo4j.conf
    
Docker Installer extension (located in the folder created when unzipping the extension):
neo4j\configuration\neo4j.conf

Info

Microsoft Windows via traditional installer

This file is located in the protected %APPDATA% location, therefore you must open the file with elevated permission (this is usually achieved by right clicking your text editor in the Windows start menu and selecting Run as administrator):

Linux

You may need to use elevated permissions to edit this file (for example use sudo).

And add the following line to increase the maximum buffer size to 20MB (from the default 10MB) - note that you may need to increase this value further if a value of 20MB does not resolve the error:

dbms.import.csv.buffer_size=20000000

Save the file and then restart the Neo4j Windows service / Docker container to ensure the changes are taken into account.