Neo4j (CSV) Batch Importer

Neo4j 2.2+ neo4j-import tool

Since version 2.2.0 Neo4j comes with an high performance import tool out of the box that takes many ideas of this one, but is way more scalable across CPUs and has little memory requirements.

The only cases that are not covered are repeated imports in existing stores and population of manual indexes. Please consider the built-in and officially supported tool first, before falling back onto this one.

The simplest invocation is /path/to/neo4j/bin/neo4j-import --into graph.db --nodes nodes.csv --relationships rels.csv with the header format being similar to this one. For a quick intro check the developer pages. There is much more to it, please see the Neo4j reference manual.

Licensing

This software is licensed under the GPLv3 for now. You can ask Neo Technology about a different licensing agreement.

Works with Neo4j 2.x

Binary Download

To simply use it (no source/git/maven required):

• download 2.2 zip
• unzip
• run import.sh test.db nodes.csv rels.csv (on Windows: import.bat)
• after the import point your /path/to/neo4j/conf/neo4j-server.properties to this test.db directory, or copy the data over to your server cp -r test.db/* /path/to/neo4j/data/graph.db/

You provide one tab separated csv file for nodes and one for relationships (optionally more for indexes)

Example data for the files is a small family network

File format

• tab separated csv files
• Property names in first row.
• If only one file is initially imported, the row number corresponds to the node-id (starting with 0)
• Property values not listed will not be set on the nodes or relationships.
• Optionally property fields can have a type (defaults to String) indicated with name:type where type is one of (int, long, float, double, boolean, byte, short, char, string). The string value is then converted to that type. Conversion failure will result in abort of the import operation.
• There is a separate "label" type, which should be used for relationship types and/or node labels, (labels:label)
• Property fields may also be arrays by adding "_array" to the types above and separating the data with commas.
• for non-ascii characters make sure to add -Dfile.encoding=UTF-8 to the commandline arguments
• Optionally automatic indexing of properties can be configured with a header like name:string:users and a configured index in batch.properties like batch_import.node_index=exact then the property name will be indexed in the users index for each row with a value there
• multiple files for nodes and rels, comma separated, without spaces like "node1.csv,node2.csv"
• you can specify concrete, externally provided node-id's with: i:id, both in the node and relationship-files
• csv files can be zipped individually as *.gz or *.zip

Examples

There is also a sample directory, please run from the main directory ./import.sh test.db sample/nodes.csv sample/rels.csv

nodes.csv

name    l:label       age works_on
Michael Person,Father 37  neo4j
Selina  Person,Child  14
Rana    Person,Child  6
Selma   Person,Child  4

rels.csv

Note that the node-id references are numbered from 0 (since Neo4j 2.0)

start	end	type	    since   counter:int
0     1   FATHER_OF	1998-07-10  1
0     2   FATHER_OF 2007-09-15  2
0     3   FATHER_OF 2008-05-03  3
2     3   SISTER_OF 2008-05-03  5
1     2   SISTER_OF 2007-09-15  7

Execution

Just use the provided shell script import.sh or import.bat on Windows

import.sh test.db nodes.csv rels.csv

For Developers

If you want to work on the code and run the importer after making changes:

mvn clean compile exec:java -Dexec.mainClass="org.neo4j.batchimport.Importer" -Dexec.args="neo4j/data/graph.db nodes.csv rels.csv"

or

java -server -Dfile.encoding=UTF-8 -Xmx4G -jar target/batch-import-jar-with-dependencies.jar neo4j/data/graph.db nodes.csv rels.csv


ynagzet:batchimport mh$ rm -rf target/db
ynagzet:batchimport mh$ mvn clean compile assembly:single
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Building Simple Batch Importer
[INFO]    task-segment: [clean, compile, assembly:single]
[INFO] ------------------------------------------------------------------------
...
[INFO] Building jar: /Users/mh/java/neo/batchimport/target/batch-import-jar-with-dependencies.jar
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESSFUL
[INFO] ------------------------------------------------------------------------
ynagzet:batchimport mh$ java -server -Xmx4G -jar target/batch-import-jar-with-dependencies.jar target/db nodes.csv rels.csv
Physical mem: 16384MB, Heap size: 3640MB

Configuration:
use_memory_mapped_buffers=false
neostore.nodestore.db.mapped_memory=200M
neostore.relationshipstore.db.mapped_memory=1000M
neostore.propertystore.db.mapped_memory=1000M
neostore.propertystore.db.strings.mapped_memory=100M
neostore.propertystore.db.arrays.mapped_memory=215M
neo_store=/Users/mh/java/neo/batchimport/test.db
dump_configuration=true
cache_type=none

...........................................................................
Importing 7500000 Nodes took 17 seconds
....................................................................................................35818 ms
....................................................................................................39343 ms
....................................................................................................41788 ms
....................................................................................................48897 ms
............
Importing 41246740 Relationships took 170 seconds
Total 212 seconds
ynagzet:batchimport mh$ du -sh test.db
3,2G	test.db

Parameters

First parameter MIGHT be the property-file name, if so it has to end with .properties, then this file will be used and all other parameters are consumed as usual

First parameter - the graph database directory, a new db will be created in the directory except when batch_import.keep_db=true is set in batch.properties.

Second parameter - a comma separated list of node-csv-files

Third parameter - a comma separated list of relationship-csv-files

It is also possible to specify those two file-lists in the config:

batch_import.nodes_files=nodes1.csv[,nodes2.csv]
batch_import.rels_files=rels1.csv[,rels2.csv]

Fourth parameter - index configuration each a set of 4 values: node_index users fulltext nodes_index.csv or more generally: node-or-rel-index index-name index-type index-file

This parameter set can be repeatedly used, see below. It is also possible to configure this in the config (batch.properties)

batch_import.node_index.users=exact

Schema indexes

Currently schema indexes are not created by the batch-inserter, you could create them upfront and use batch_import.keep_db=true to work with the existing database. You then have the option of specifying labels for your nodes using a column header like type:label and a comma separated list of label values. Then on shutdown of the import Neo4j will populate the schema indexes with nodes with the appropriate labels and properties automatically. (The index creation is As a rough estimate the index creation will

(Legacy) Indexing

Indexing of inserted properties

You can automatically index properties of nodes and relationships by adding ":indexName" to the property-column-header. Just configure the indexes in batch.properties like so:

batch_import.node_index.users=exact

name:string:users    age works_on
Michael 37  neo4j
Selina  14
Rana    6
Selma   4

If you use node_auto_index as the index name, you can also initially populate Neo4j's automatic node index which is then later used and and updated while working with the database.

In the relationships-file you can optionally specify that the start and end-node should be looked up from the index in the same way

name:string:users	name:string:users	type	    since   counter:int
Michael     Selina   FATHER_OF	1998-07-10  1
Michael     Rana   FATHER_OF 2007-09-15  2
Michael     Selma   FATHER_OF 2008-05-03  3
Rana     Selma   SISTER_OF 2008-05-03  5
Selina     Rana   SISTER_OF 2007-09-15  7

Explicit Indexing

Optionally you can add nodes and relationships to indexes.

Add four arguments per each index to command line:

To create a full text node index called users using nodes_index.csv:

node_index users fulltext nodes_index.csv

To create an exact relationship index called worked using rels_index.csv:

rel_index worked exact rels_index.csv

Example command line:

./import.sh test.db nodes.csv rels.csv node_index users fulltext nodes_index.csv rel_index worked exact rels_index.csv

Using Neo4j's Automatic Indexing

The auto-indexing elsewhere in this file pertains to the batch inserter's ability to automatically index. If you want to use this cool feature from the batch inserter, there's a little gotcha. You still need to enable the batch inserter's feature with batch_import.node_index but then instead of specifying the name of a regular index, specify the auto index's name like so:

batch_import.node_index.node_auto_index=exact

And you have to make sure to also enable automatic indexing in your regular Neo4j database's (conf/neo4j.properties) and specify the correct node properties to be indexed.

Examples

nodes_index.csv

id	name	language
0	Victor Richards	West Frisian
1	Virginia Shaw	Korean
2	Lois Simpson	Belarusian
3	Randy Bishop	Hiri Motu
4	Lori Mendoza	Tok Pisin

rels_index.csv

id	property1	property2
0	cwqbnxrv	rpyqdwhk
1	qthnrret	tzjmmhta
2	dtztaqpy	pbmcdqyc

Configuration

The Importer uses a supplied batch.properties file to be configured:

Memory Mapping I/O Config

Most important is the memory config, you should try to have enough RAM map as much of your store-files to memory as possible.

At least the node-store and large parts of the relationship-store should be mapped. The property- and string-stores are mostly append only so don't need that much RAM. Below is an example for about 6GB RAM, to leave room for the heap and also OS and OS caches.

cache_type=none
use_memory_mapped_buffers=true
# 14 bytes per node
neostore.nodestore.db.mapped_memory=200M
# 33 bytes per relationships
neostore.relationshipstore.db.mapped_memory=3G
# 38 bytes per property
neostore.propertystore.db.mapped_memory=500M
# 60 bytes per long-string block
neostore.propertystore.db.strings.mapped_memory=500M
neostore.propertystore.db.index.keys.mapped_memory=5M
neostore.propertystore.db.index.mapped_memory=5M

Indexes (experimental)

batch_import.node_index.users=exact
batch_import.node_index.articles=fulltext
batch_import.relationship_index.friends=exact

CSV (experimental)

batch_import.csv.quotes=true // default, set to false for faster, experimental csv-reader
batch_import.csv.delim=,

Index-Cache (experimental)

batch_import.mapdb_cache.disable=true

Keep Database (experimental)

batch_import.keep_db=true

Utilities

TestDataGenerator

It is a dumb random test data generator (org.neo4j.batchimport.TestDataGenerator) that you can run with

./generate.sh #nodes #max-rels-per-node REL1,REL2,REL3 LABEL1,LABEL2,LABEL3

Will generate nodes.csv and rels.csv for those numbers

Relationship-Sorter

Sorts a given relationship-CSV file by min(start,end) as required for the parallel sorter. Uses the data-pump sorter from mapdb for the actual sorting with a custom Comparator.

org.neo4j.batchimport.utils.RelationshipSorter rels-input.csv rels-output.csv