Lots of byte[] in meory

[Yogesh_BG]

Hi

I am using elasticsearch java client 6.6.0

I do index lot of documents ~10K per second, almost 5MB per second
i am using async api as below, i dont do any action.get, i dont want to check the response, its okay if it fails

bulkRequests.execute();

over a period of time lot of byte objects get accumulated as attached in picture its almost 70% of memory

i had set the below property it didn't help,
System.setProperty("io.netty.allocator.type", "unpooled");
can anyone help me?