Golang opensearch client cause high cpu in opendistro coordinating (client) node

golang opensearch client library version: v2.3.0
opendistro verion: 1.12

I am indexing about 7-8K events per second and the coordinating(client) node is reaching 60%
I have also python application indexing 60K events per second causing the coordinating node CPU to reach about 10%.
I am using bulk API with 5k bulk size.

bulk := “{ "create": { "_index": "myindex" }}\n{"value1":1, "value2": 2}…”
response, err := opensearchClient.Bulk(bytes.NewReader(byte(bulk)))


cfg := opensearch.Config{
Addresses: string{
Username: “user”,
Password: “password”,
Transport: &http.Transport{
MaxIdleConnsPerHost: 10,
ResponseHeaderTimeout: time.Duration(180) * time.Second,
DialContext: (&net.Dialer{Timeout: time.Duration(30) * time.Second}).DialContext,
TLSClientConfig: &tls.Config{
MinVersion: tls.VersionTLS11,
InsecureSkipVerify: true,
opensearchClient, err := opensearch.NewClient(cfg)

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