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Asked: 2026-06-04T13:59:37+00:00

I’m working with a quite big Neo4J setup with more than 60,000 nodes. Each

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I’m working with a quite big Neo4J setup with more than 60,000 nodes. Each node has about 4~5 properties and a simple parent->child relationship. When working with those 60,000 nodes, specially in queries that are expensive and repetitive, i’m getting various 500 HTTP errors through Neo4J’s REST interface.

After going through the logs, i found that Java heap space was the problem. I cranked up the 512 MB limit to 2048 MB but it’s still giving me 500. If i set the heap to something like 3GB or 4GB, neo4j doesn’t even start. I’m testing this on a quite good laptop (i5, 4GB RAM) and i really want to know if this is a configuration problem or if the application will perform ok on my server (an Amazon Extra-Large High-CPU instance). Is there some sort of caching that can help me get things faster? Basically, i’m iterating over the entire network of nodes multiple times.

I’m running two queries. The first is:

start referrer=node(3) match path=referrer-[*1..1]->referral return referral

Which is done to discover the nodes which are Tier 1 for the Referrer #3. Then, i have to discover all nodes from all his tiers, returning the node, nodes from the first tier and then the tier number. 

start referrer=node(3) match path=referrer-[*1..1]->firsttier-[*0..]->referral return referral, firsttier, length(path)

It works perfectly and it’s quite fast. However, i’m doing this for ALL the nodes in my network. I’m running both queries (and applying business logic with them) inside a for loop. The loop runs 60,000 times.

Right now i’m testing this on my laptop, however, this “task” has been prepared for distributed processing, since i made everything with ZeroMQ. The for loop sends messages to workers and workers make the queries.

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  1. Editorial Team

    60,000 nodes is small for Neo4j — it can go up to 32 billion+ — but you need to increase the heap size in the config.

    See http://blog.neo4j.org/2011/03/neo4j-13-abisko-lampa-m04-size-really.html

    However, you probably want to limit the number of nodes you return over REST and page them.

    Or you might consider returning all the IDs, caching them in your app or something like Redis, and then doing a multi-get with Cypher on the IDs. This way you aren’t running the query every time.

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