(I'm posting this question here since it seems a bit too non-specific for Stack Overflow).
I've been working on a Neo4j system that needs to ingest a lot of data. We've been testing the data-load with many writing threads. Generally this works fine. For example, writing with 5 threads completes normally. Writing with 10 threads however works fine (in fact ~2x speed) for a while, but then suddenly every transaction starts timing out, even though CPU usage was generally less than 50%. Also, it doesn't fully recover for a long time if ever. Even minutes after the load has been completely turned off, Neo still remains unresponsive to certain kinds of queries - for example, I have a script that runs "MATCH (a) WITH a LIMIT 10000 OPTIONAL MATCH (a)-[r]-() DELETE a,r RETURN COUNT(*)" repeatedly which normally works fine when run by itself, but in this case it keeps timing out even when there are no other queries. I have to kill and restart the process. Needless to say this behaviour is less than ideal. I tried adding a "max-execution-time" header of 5 seconds but this didn't seem to help much if at all. In other tests I've seen weird spikes of bad performance 30 mins to a few hours after one of these meltdowns, in a kind of "echo", even when the load has been greatly reduced in the meantime (and when normally that load would sustain good performance indefinitely). Any idea what's going on? TL;DR: Neo fails abruptly under heavy load and seems slow to recover even when the load is removed. Thanks, Ryan Sattler -- You received this message because you are subscribed to the Google Groups "Neo4j" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
