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Tool to copy Neo4j Stores

Uses the BatchInserterImpl to read a store and write the target store keeping the node-ids. Copies the manual (legacy) index-files as is, please note it performs no index upgrade!

You will have to recreate any schema indexes too.

Ignores broken nodes and relationships and records them in target/store-copy.log

Also useful to skip no longer wanted properties, relationships with a certain type. Or of certain labels and even nodes with certain labels.

Good for store compaction and reorganization of relationships and properties as it rewrites the store file reclaiming space that is sitting empty.

NOTE: With Neo4j 3.x there are two different store formats, so you have to provide "enterprise" or "community" as first argument of the call!

You can now also decide if you want to compact the node-store, then you have to pass "false" as the parameter for keep-node-ids.

Config is read from neo4j.properties file in current directory if it exists, but command line options override.

neo4j.properties

source_db_dir=
target_db_dir=

keep_node_ids=true

properties_to_ignore=
labels_to_ignore=
labels_to_delete=
rel_types_to_ignore=

store_copy_log_dir=
bad_entries_log_dir=

Store Copy

copy-store.sh [enterprise|community] source.db target.db [RELS,TO,SKIP] [props,to,skip] [Labels,To,Skip] [Labels,To,Delete,Nodes] [keep-node-ids:true/false]

The provided script contains these settings for page-cache (note you can configure a different, smaller setting for the source store than the target store).

dbms.pagecache.memory.source=2G
dbms.pagecache.memory=2G

Heap config is in the shell-script, default is:

export MAVEN_OPTS="-Xmx4G -Xms4G -Xmn1G -XX:+UseG1GC"

Please adapt the settings as needed for your store.

Please note that you will need the memory for (source-page-cache + target-page-cache + 1x heap) as it opens 2 databases one for reading and one for writing.

Change the Neo4j version in pom.xml before running as needed. (Currently 3.1.0)

Optionally changeable from the outside with -Dneo4j.version=3.1.0 on the mvn invocation.

Internally

Note: It calls under the hood:

mvn compile exec:java -Dexec.mainClass="org.neo4j.tool.StoreCopy" -Penterprise \
  -Dexec.args="source-dir target-dir [REL,TYPES,TO,IGNORE] [properties,to,ignore] [Labels,To,Ignore] [Labels,To,Delete,Nodes] [keep-node-ids:true/false]"