Parallel in all socket while apoc.periodic.iterate

Neo4j Graph Platform
1

There're two socket of cpu with each 8 core & 16 thread in my computer (i.e., total 2*8 core and 16*2 thread).

When I was running apoc.periodic.iterate with parallel = TRUE, for example,

CALL apoc.periodic.iterate(

'MATCH (n) RETURN id(n) AS id',
'MATCH (n) WHERE id(n)=id DELETE n',
{batchSize: 5000, parallel :true});

I find (using HWiNFO64 and task manager) that It did parallel but only in one of socket's cpu, i.e, only 8 core were parallel, others (16-8=8) were not running.

Question : Is this the limitation of neo4j that it can only parallel in one socket's cpu, or is there any method to solve this problem (that I want to parallel in all socket, i.e., all CPU but not just one of socket)

By the way, I notice that the parallel method in Neo4j is "multi-process". Can neo4j parallel in multi-thread?

Thanks.

2

Hello @Peter_Lian :blush:

Did try to play with the concurrency parameter?

Moreover, if you want to erase the whole database, you should use CREATE OR REPLACE DATABASE name_of_your_database

Regards,
Cobra

3

No, how to set concurrency parameter?

The example of apoc.periodic.iterate just an example, but thanks for your suggestion !

4

For example:

CALL apoc.periodic.iterate(
    "MATCH (n) RETURN n",
    "SET n.value = true",
    {batchSize:100, parallel:true, concurrency:4}
)

Regards,
Cobra