1
votes

I'm using Neo4j 3.2.1 on linux machine of 16G RAM . I'm tryng to load a graph from a csv file of 11M row, the max number of node is for about 150K node. It is taking forever to load, I have tried to increase the heap size , using periodic commit from 10000 to 100000 but still nothing is changing it is hanging for about 2 hours now. I looked up the internet and found that it should not be taking that much time here is the configuration file

#*****************************************************************
# Neo4j configuration
#
# For more details and a complete list of settings, please see
# https://neo4j.com/docs/operations-manual/current/reference/configuration-settings/
#*****************************************************************

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

# Paths of directories in the installation.
#dbms.directories.data=data
#dbms.directories.plugins=plugins
#dbms.directories.certificates=certificates
#dbms.directories.logs=logs
#dbms.directories.lib=lib
#dbms.directories.run=run

# This setting constrains all `LOAD CSV` import files to be under the `import` directory. Remove or comment it out to
# allow files to be loaded from anywhere in the filesystem; this introduces possible security problems. See the
# `LOAD CSV` section of the manual for details.
dbms.directories.import=import

# Whether requests to Neo4j are authenticated.
# To disable authentication, uncomment this line
#dbms.security.auth_enabled=false

# Enable this to be able to upgrade a store from an older version.
dbms.allow_format_migration=true

# Java Heap Size: by default the Java heap size is dynamically
# calculated based on available system resources.
# Uncomment these lines to set specific initial and maximum
# heap size.
dbms.memory.heap.initial_size=512m
dbms.memory.heap.max_size=15400m

# The amount of memory to use for mapping the store files, in bytes (or
# kilobytes with the 'k' suffix, megabytes with 'm' and gigabytes with 'g').
# If Neo4j is running on a dedicated server, then it is generally recommended
# to leave about 2-4 gigabytes for the operating system, give the JVM enough
# heap to hold all your transaction state and query context, and then leave the
# rest for the page cache.
# The default page cache memory assumes the machine is dedicated to running
# Neo4j, and is heuristically set to 50% of RAM minus the max Java heap size.
dbms.memory.pagecache.size=14g

#*****************************************************************
# Network connector configuration
#*****************************************************************

# With default configuration Neo4j only accepts local connections.
# To accept non-local connections, uncomment this line:
dbms.connectors.default_listen_address=0.0.0.0

# You can also choose a specific network interface, and configure a non-default
# port for each connector, by setting their individual listen_address.

# The address at which this server can be reached by its clients. This may be the server's IP address or DNS name, or
# it may be the address of a reverse proxy which sits in front of the server. This setting may be overridden for
# individual connectors below.
#dbms.connectors.default_advertised_address=localhost

# You can also choose a specific advertised hostname or IP address, and
# configure an advertised port for each connector, by setting their
# individual advertised_address.

# Bolt connector
dbms.connector.bolt.enabled=true
#dbms.connector.bolt.tls_level=OPTIONAL
#dbms.connector.bolt.listen_address=:7687

# HTTP Connector. There must be exactly one HTTP connector.
dbms.connector.http.enabled=true
#dbms.connector.http.listen_address=:7474

# HTTPS Connector. There can be zero or one HTTPS connectors.
dbms.connector.https.enabled=true
#dbms.connector.https.listen_address=:7473

# Number of Neo4j worker threads.
#dbms.threads.worker_count=

#*****************************************************************
# Logging configuration
#*****************************************************************

# To enable HTTP logging, uncomment this line
#dbms.logs.http.enabled=true

# Number of HTTP logs to keep.
#dbms.logs.http.rotation.keep_number=5

# Size of each HTTP log that is kept.
#dbms.logs.http.rotation.size=20m

# To enable GC Logging, uncomment this line
#dbms.logs.gc.enabled=true

# GC Logging Options
# see http://docs.oracle.com/cd/E19957-01/819-0084-10/pt_tuningjava.html#wp57013 for more information.
#dbms.logs.gc.options=-XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCApplicationStoppedTime -XX:+PrintPromotionFailure -XX:+PrintTenuringDistribution

# Number of GC logs to keep.
#dbms.logs.gc.rotation.keep_number=5

# Size of each GC log that is kept.
#dbms.logs.gc.rotation.size=20m

# Size threshold for rotation of the debug log. If set to zero then no rotation will occur. Accepts a binary suffix "k",
# "m" or "g".
#dbms.logs.debug.rotation.size=20m

# Maximum number of history files for the internal log.
#dbms.logs.debug.rotation.keep_number=7

#*****************************************************************
# Miscellaneous configuration
#*****************************************************************

# Enable this to specify a parser other than the default one.
#cypher.default_language_version=3.0

# Determines if Cypher will allow using file URLs when loading data using
# `LOAD CSV`. Setting this value to `false` will cause Neo4j to fail `LOAD CSV`
# clauses that load data from the file system.
#dbms.security.allow_csv_import_from_file_urls=true

# Retention policy for transaction logs needed to perform recovery and backups.
dbms.tx_log.rotation.retention_policy=1 days

# Enable a remote shell server which Neo4j Shell clients can log in to.
#dbms.shell.enabled=true
# The network interface IP the shell will listen on (use 0.0.0.0 for all interfaces).
#dbms.shell.host=127.0.0.1
# The port the shell will listen on, default is 1337.
#dbms.shell.port=1337

# Only allow read operations from this Neo4j instance. This mode still requires
# write access to the directory for lock purposes.
#dbms.read_only=false

# Comma separated list of JAX-RS packages containing JAX-RS resources, one
# package name for each mountpoint. The listed package names will be loaded
# under the mountpoints specified. Uncomment this line to mount the
# org.neo4j.examples.server.unmanaged.HelloWorldResource.java from
# neo4j-server-examples under /examples/unmanaged, resulting in a final URL of
# http://localhost:7474/examples/unmanaged/helloworld/{nodeId}
#dbms.unmanaged_extension_classes=org.neo4j.examples.server.unmanaged=/examples/unmanaged

#********************************************************************
# JVM Parameters
#********************************************************************

# G1GC generally strikes a good balance between throughput and tail
# latency, without too much tuning.
dbms.jvm.additional=-XX:+UseG1GC

# Have common exceptions keep producing stack traces, so they can be
# debugged regardless of how often logs are rotated.
dbms.jvm.additional=-XX:-OmitStackTraceInFastThrow

# Make sure that `initmemory` is not only allocated, but committed to
# the process, before starting the database. This reduces memory
# fragmentation, increasing the effectiveness of transparent huge
# pages. It also reduces the possibility of seeing performance drop
# due to heap-growing GC events, where a decrease in available page
# cache leads to an increase in mean IO response time.
# Try reducing the heap memory, if this flag degrades performance.
dbms.jvm.additional=-XX:+AlwaysPreTouch

# Trust that non-static final fields are really final.
# This allows more optimizations and improves overall performance.
# NOTE: Disable this if you use embedded mode, or have extensions or dependencies that may use reflection or
# serialization to change the value of final fields!
dbms.jvm.additional=-XX:+UnlockExperimentalVMOptions
dbms.jvm.additional=-XX:+TrustFinalNonStaticFields

# Disable explicit garbage collection, which is occasionally invoked by the JDK itself.
dbms.jvm.additional=-XX:+DisableExplicitGC

# Remote JMX monitoring, uncomment and adjust the following lines as needed. Absolute paths to jmx.access and
# jmx.password files are required.
# Also make sure to update the jmx.access and jmx.password files with appropriate permission roles and passwords,
# the shipped configuration contains only a read only role called 'monitor' with password 'Neo4j'.
# For more details, see: http://download.oracle.com/javase/8/docs/technotes/guides/management/agent.html
# On Unix based systems the jmx.password file needs to be owned by the user that will run the server,
# and have permissions set to 0600.
# For details on setting these file permissions on Windows see:
#     http://docs.oracle.com/javase/8/docs/technotes/guides/management/security-windows.html
#dbms.jvm.additional=-Dcom.sun.management.jmxremote.port=3637
#dbms.jvm.additional=-Dcom.sun.management.jmxremote.authenticate=true
#dbms.jvm.additional=-Dcom.sun.management.jmxremote.ssl=false
#dbms.jvm.additional=-Dcom.sun.management.jmxremote.password.file=/absolute/path/to/conf/jmx.password
#dbms.jvm.additional=-Dcom.sun.management.jmxremote.access.file=/absolute/path/to/conf/jmx.access

# Some systems cannot discover host name automatically, and need this line configured:
#dbms.jvm.additional=-Djava.rmi.server.hostname=$THE_NEO4J_SERVER_HOSTNAME

# Expand Diffie Hellman (DH) key size from default 1024 to 2048 for DH-RSA cipher suites used in server TLS handshakes.
# This is to protect the server from any potential passive eavesdropping.
dbms.jvm.additional=-Djdk.tls.ephemeralDHKeySize=2048

#********************************************************************
# Wrapper Windows NT/2000/XP Service Properties
#********************************************************************
# WARNING - Do not modify any of these properties when an application
#  using this configuration file has been installed as a service.
#  Please uninstall the service before modifying this section.  The
#  service can then be reinstalled.

# Name of the service
dbms.windows_service_name=neo4j

#********************************************************************
# Other Neo4j system properties
#********************************************************************
dbms.jvm.additional=-Dunsupported.dbms.udc.source=tarball

After a long time loading I have this error

Java HotSpot(TM) 64-Bit Server VM warning: INFO: os::commit_memory(0x000000072c000000, 497025024, 0) failed; error='Ne peut allouer de l                        a mémoire' (errno=12)
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (mmap) failed to map 497025024 bytes for committing reserved memory.

How can I solve this?

Query

CREATE CONSTRAINT ON (n:Node) ASSERT n.NodeID IS UNIQUE;
USING PERIODIC COMMIT  100000

LOAD CSV WITH HEADERS FROM 'file:///file.csv'
AS line

MERGE (n1:Node {NodeID: line.p1})
MERGE (n2:Node {NodeID: line.p2})
MERGE (n1)-[:ACTING_WITH_L {Score: TOFLOAT(line.score)}]->(n2);
1
Can you provide your indexes/constraints, and your LOAD CSV query?InverseFalcon
@InverseFalcon I have added the query to the postMuna arr

1 Answers

2
votes

When I ran an EXPLAIN of your query, I noticed an EAGER operation in there. When EAGER is a part of the plan when using LOAD CSV, it falls back to a means of processing where it does not use PERIODIC COMMIT, and you run into memory issues.

Here's a blog post about this, including the solution: ensure nodes are merged into the graph as a separate operation, and when you are sure the nodes are loaded, process the relationships separately MATCHing to nodes instead of using MERGE.

Instead of the MERGE ... MERGE ... MERGE pattern to merge in both nodes, then the relationship, use MATCH ... MATCH ... MERGE. Also, if you're sure none of the relationships exist in the graph already, you may want to use CREATE instead of MERGE on the relationship to speed it up.