Inquiry About normal_transfer_queue_consumer Thread Pool in OpenSearch

OpenSearch
1

Hi ,

We are deploying OpenSearch in a Kubernetes environment with three pods — one each for the client, manager, and data roles.

Currently, we are not ingesting any data into OpenSearch, and there are no indices present in the system.

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However, we’ve observed that a thread pool named normal_transfer_queue_consumer is active, with 24 threads running on each pod.

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I reviewed the OpenSearch documentation but couldn’t find any information related to this specific thread pool.

Could you please provide details about the purpose of the normal_transfer_queue_consumer thread pool and its intended use case?

2

Hi @Varun_Srinivasa ,

The normal_transfer_queue_consumer thread pool is created by default in OpenSearch. It is used for facilitating communication and data movement within the cluster.

In essence, while you don’t have to directly configure it, normal_transfer_queue_consumer is a vital, low-level component that OpenSearch automatically manages to ensure smooth and reliable data flow between its nodes, which is fundamental to its operation as a distributed database and search engine.

Leeroy.

3

Hi @Leeroy ,

Thanks for your reply.

In my case normal_transfer_queue_consumer is always active and it’s count is 24. Will there be any performance impact ? Any reason why the thread count is 24.

Below is the resource configuration used for opensearch pods

manager:
replicas: 1
resources:
limits:
#cpu: “1”
memory: “2Gi”
requests:
cpu: “500m”
memory: “1.5Gi”
java_opts: “-Xms1g -Xmx1g”

data:
replicas: 1
resources:
limits:
#cpu: “1”
memory: “4Gi”
requests:
cpu: “500m”
memory: “3Gi”
java_opts: “-Xms2g -Xmx2g”

client:
replicas: 1
resources:
limits:
#cpu: “1”
memory: “4Gi”
requests:
cpu: “500m”
memory: “3Gi”
java_opts: “-Xms2g -Xmx2g”

4

Hi @Leeroy ,

  1. There is any parameter to changes this number of thread normal_transfer_queue_consumer during startup?
  2. If we reduce number of normal_transfer_queue_consumer threads or disable it (changes to 0), will it have any impact to the system?

Regards,
Varun S