Cannot restart an offline DB with Java out of memory error

Neo4j Graph Platform
1

Per this SO, Neo4j: How to bring database back online - Stack Overflow

I was deleting 3 million nodes when I got an out of memory. Now I can not restart the DB. The log file shows a Java out of memory error. I think the key line is this:

Exception in thread "neo4j.Scheduler-1" java.lang.OutOfMemoryError: Java heap space

Presumably the DB is trying to continue with the large query on restart. Is there a way to clear this down?

BUMP - It's nearly 24 hours since I raised this problem, both here and Stackoverflow, with no response.

This is more of an observation than a complaint, but it does make it difficult to see how I could use this in production, even with paid support. In addition, I have seen similarly fatal errors where the response has been 'restore from backup', which compounds the problem.

2

Hi @KimPrince

My Env

Neo4j Desktop 1.4.7
Neo4j Enterprise 4.3.2
APOC 4.3.0.0

I have created 1,000,000 nodes and 3,000,000 relationships data.

CALL apoc.generate.ba(1000000, 3, 'Foo', 'TEST_REL_TYPE');

And I use "apoc.periodic.iterate".

CALL apoc.periodic.iterate(
"MATCH (n:Foo) RETURN n",
"DETACH DELETE n",
{batchSize:1000})
3

Thanks Koji, but I can't get the server restarted.

4

@KimPrince

Is it possible to change the parameters of neo4j.conf?
4G or 8G or 16G, etc.

dbms.memory.heap.initial_size=512m
dbms.memory.heap.max_size=1G

And Restart Neo4j.

1 Like
5

Thanks Koji, that fixed it immediately!

1 Like