Running Neo4j purely in memory without any persist

问题:

I don't want to persist any data but still want to use Neo4j for it's graph traversal and algorithm capabilities. In an embedded database, I've configured cache_type = strong and after all the writes I set the transaction to failure. But my write speeds (node, relationship creation speeds) are a slow and this is becoming a big bottleneck in my process.

So, the question is, can Neo4j be run without any persistence aspects to it at all and just as a pure API? I tried others like JGraphT but those don't have traversal mechanisms like the ones Neo4j provides.

回答1:

As far as I know, Neo4J data storage and Lucene indexes are always written to files. On Linux, at least, you could set up a ramfs filing system to hold the files in-memory.

See also:

• Loading all Neo4J db to RAM

回答2:

How many changes do you group in each transaction? You should try to group up to thousands of changes in each transaction since committing a transaction forces the logical log to disk.

However, in your case you could instead begin your transactions with:

db.tx().unforced().begin();

Instead of:

db.beginTx();

Which makes that transaction not wait for the logical log to force to disk and makes small transactions much faster, but a power outage could have you lose the last couple of seconds of data potentially.

The tx() method sits on GraphDatabaseAPI, which for example EmbeddedGraphDatabase implements.

回答3:

you can try a virtual drive. It would make neo4j persist to the drive, but it would all happen in memory https://thelinuxexperiment.com/create-a-virtual-hard-drive-volume-within-a-file-in-linux/