Knowledge Base

An example of neo4j-import steps in a Causal Cluster environment

The following steps are provided to describe how to use neo4j-import in a Causal Cluster environment and was run from an environment of a single linux host with 3 copies for Neo4j 3.1.2 installed in the following paths

~/HA/ha1/neo4j-enterprise-3.1.2
~/HA/ha2/neo4j-enterprise-3.1.2
~/HA/ha3/neo4j-enterprise-3.1.2

This is similar to the instructions for Set up a local Causal Cluster

  • validated a Causal Cluster would form (after configuring $NEO4J_HOME/cond/neo4j.conf) and ran

~/HA/ha1/neo4j-enterprise-3.1.2/bin/neo4j start; ~/HA/ha2/neo4j-enterprise-3.1.2/bin/neo4j start;
~/HA/ha3/neo4j-enterprise-3.1.2/bin/neo4j start

this assumes the default database of graph.db

Since starting a Causal Cluster takes a number of configurations I wanted to ensure that it would at least start and with an empty database.

  • stopped the causal cluster by by running

~/HA/ha1/neo4j-enterprise-3.1.2/bin/neo4j stop; ~/HA/ha2/neo4j-enterprise-3.1.2/bin/neo4j stop;
~/HA/ha3/neo4j-enterprise-3.1.2/bin/neo4j stop

which produced the following output

Stopping Neo4j..................................... stopped
Stopping Neo4j.................................... stopped
Stopping Neo4j..................................... stopped

  • unbound each of the 3 causal cluster databases. (this is not necessary if you skip #1 and #2 but if you have failure further on with getting the cluster to form then you need to sort out if it is a cluster configuration issue or something about the database import). Further unbind is detailed here

$ ~/HA/ha2/neo4j-enterprise-3.1.2/bin/neo4j-admin unbind --database=graph.db
$ ~/HA/ha1/neo4j-enterprise-3.1.2/bin/neo4j-admin unbind --database=graph.db
$ ~/HA/ha3/neo4j-enterprise-3.1.2/bin/neo4j-admin unbind --database=graph.db

  • created ~/HA/ha1/neo4j-enterprise-3.1.2/importer and added 3 files namely actors.csv, movies.csv, roles.csv and they are defined with content detailed here

  • ran neo4j-import and loaded the data into ~/HA/ha1/neo4j-enterprise-3.1.2/data/databases/graph.db.importer

~/HA/ha1/neo4j-enterprise-3.1.2/bin/neo4j-import --into ~/HA/ha1/neo4j-enterprise-3.1.2/data/databases/graph.db.importer --nodes ~/HA/ha1/neo4j-enterprise-3.1.2/importer/movies.csv --nodes ~/HA/ha1/neo4j-enterprise-3.1.2/importer/actors.csv --relationships ~/HA/ha1/neo4j-enterprise-3.1.2/importer/roles.csv

and this produced the following output

WARNING: neo4j-import is deprecated and support for it will be removed in a future
version of Neo4j; please use neo4j-admin import instead.

Neo4j version: 3.1.2
Importing the contents of these files into /home/neo4j/HA/ha1/neo4j-enterprise-3.1.2/data/databases/graph.db.importer:
Nodes:
  /home/neo4j/HA/ha1/neo4j-enterprise-3.1.2/importer/movies.csv

  /home/neo4j/HA/ha1/neo4j-enterprise-3.1.2/importer/actors.csv
Relationships:
  /home/neo4j/HA/ha1/neo4j-enterprise-3.1.2/importer/roles.csv

Available resources:
  Free machine memory: 5.01 GB
  Max heap memory : 1.47 GB
  Processors: 1

Nodes

Done in 100ms
Prepare node index

Done in 26ms
Calculate dense nodes

Done in 43ms
Node --> Relationship Sparse

Done in 10ms
Relationship --> Relationship Sparse

Done in 11ms
Minority relationships

Done in 32ms
Count groups

Done in 10ms
Gather

Done in 11ms
Write

Done in 10ms
Node --> Group

Done in 11ms
Node counts

Done in 53ms
Relationship counts

Done in 11ms

IMPORT DONE in 1s 881ms.
Imported:
  6 nodes
  0 relationships
  15 properties
Peak memory usage: 7.63 MB

  • updated each of the 3 $NEO4J_HOME/conf/neo4j.conf and defined the

# The name of the database to mount
dbms.active_database=graph.db.importer

as this represents the name of the database prepared from neo4j-import.

  • copy the graph.db.importer from instance 1 to instance 2 and 3 via a

cp -R ~/HA/ha1/neo4j-enterprise-3.1.2/data/databases/graph.db.importer ~/HA/ha2/neo4j-enterprise-3.1.2/data/databases/graph.db.importer
cp -R ~/HA/ha1/neo4j-enterprise-3.1.2/data/databases/graph.db.importer ~/HA/ha3/neo4j-enterprise-3.1.2/data/databases/graph.db.importer

  • start all 3 instances as follows

~/HA/ha1/neo4j-enterprise-3.1.2/bin/neo4j start;  ~/HA/ha2/neo4j-enterprise-3.1.2/bin/neo4j start;
~/HA/ha3/neo4j-enterprise-3.1.2/bin/neo4j start

which produces the following output:

Starting Neo4j.
Started neo4j (pid 3976). It is available at http://0.0.0.0:7414/
There may be a short delay until the server is ready.
See /home/neo4j/HA/ha1/neo4j-enterprise-3.1.2/logs/neo4j.log for current status.
Starting Neo4j.
Started neo4j (pid 4040). It is available at http://0.0.0.0:7424/
There may be a short delay until the server is ready.
See /home/neo4j/HA/ha2/neo4j-enterprise-3.1.2/logs/neo4j.log for current status.
Starting Neo4j.
Started neo4j (pid 4104). It is available at http://0.0.0.0:7434/
There may be a short delay until the server is ready.
See /home/neo4j/HA/ha3/neo4j-enterprise-3.1.2/logs/neo4j.log for current status.

ran match (n) return n limit 10 on each of the 3 instances and all reported a total of 6 nodes, which corresponds to the output of neo4j-import which reports

Imported:
  6 nodes
  0 relationships
  15 properties

  • From the leader I ran:

create (n:Tester {id:105});

and validated it was created on the leader as well as the followers.