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I am trying to retrieve all the fields from the joined tables. The size of the result is supposed to be 5893886 records. Every time I try to run this query using Neo4j driver for Scala, I get this kind of error:

Exception in thread "dispatcher-event-loop-4" *** java.lang.instrument ASSERTION FAILED ***: "!errorOutstanding" with message can't create byte array at JPLISAgent.c line: 813
*** java.lang.instrument ASSERTION FAILED ***: "!errorOutstanding" with message can't create byte array at JPLISAgent.c line: 813
java.lang.OutOfMemoryError: Java heap space

How should I optimize my query or tune settings to fix this error? My query looks like this: 

MATCH (m:Member)-[mg_r:PARTICIPATE_IN]->(g:Group)
RETURN m.member_id, m.member_join_id, m.bio, m.city, m.country,
  m.joined, m.lat, m.link, m.lon, m.member_name, m.state,
  m.member_status, m.visited, m.group_id, g.group_id, g.category_id,
  g.category_name, g.city_id, g.city, g.country, g.created, g.join_mode,
  g.lat, g.link, g.lon, g.members, g.rating

Also, Neo4j conf file contents look this way:

dbms.allow.upgrade=true
dbms.allow.format.migration=true
dbms.security.allow.csv.import.from.file.urls=true
wrapper.java.additional=-Dneo4j.ext.udc.source=docker
ha.host.data=350d989e7781:6001
ha.host.coordination=350d989e7781:5001
dbms.tx_log.rotation.retention_policy=100M size
dbms.memory.pagecache.size=512M
dbms.memory.heap.max_size=1024M
dbms.memory.heap.initial_size=1024M
cybersam
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Cassie
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1 Answers1

1

You are trying to perform a query that require more RAM than Neo4j is able to provide.So you need to increase the heap size.

Can you try this Neo4j settings : 

dbms.memory.heap.max_size=2048M
dbms.memory.heap.initial_size=2048M

Cheers

logisima
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