Neo4j slow query caused SSLException: SSL peer shut down incorrectly

Recently I ran into the exception “SSLException: SSL peer shut down incorrectly“. My thoughts when seeing the exception were that the neo4j instance went down, some connection parameters have changed, issues with SSL certificates etc …  I did not think the code had an issue because all the integration tests had passed, and I verified everything worked on my local machine.

After debugging for a few hours, I realized the issue was because of fetching too much data at once. I was using a query Spring Data Neo4j to fetch all nodes of a label with depth 3. Because some of the nodes were dense, the query kept on running and eventually took down the server.

MATCH (n:`NodeCategory`) WITH n ORDER BY n.order MATCH p=(n)-[*0..3]-(m) RETURN p

If you see the message “SSL peer shutdown incorrectly“, besides connection parameters and configurations, be sure to watch out for slow queries or long operations.