How to Flush Cache

[t11]

i have run couple of bench-marking test and then delete all recods with delet query. but the ram utlization is 70% wondering how to clear the memory . i have restart cluster but ram is still on same utlitization.
haven't found any clue how to flush cache.
store size is showing 33.57 GiB
hit ratio and usage ration is 100%

[david_allen]

Can you say more about what you're trying to accomplish? In general, when Neo4j starts, it tries to warm up its page cache for best performance, which is probably why you're seeing the page cache getting used early on.

[t11]

in short if there is no data in DB I have delete by using MATCH (n) DETACH DELETE n; but the memory is still on 70% of 16GB ram. before these benchmarking it was below 30% this is what i want to know is this normal or some thing i have to clear .

[david_allen]

It should be normal. Neo4j tries to use what memory you provide, according to your database's initial settings. This article gives a lot more details:

https://neo4j.com/docs/operations-manual/current/performance/memory-configuration/

As an example, if you say that your initial heap size in your configuration should be 8gb, it will immediately grab that at startup, whether or not it needs all of that memory. Similar for page cache. How much memory is allocated is often less useful than knowing what's in it, and what the query workload is.