Cannot get new connection from pool.

[haobin-ihealth]

(check apply)

• read the contribution guideline
• (optional) already reported 3rd party upstream repository or mailing list if you use k8s addon or helm charts.

Steps to replicate

<match proapi.**>
    @type opensearch
    index_name proapi
    host xxxxxxxxx
    port 443
    user xxxxxxxxx
    password xxxxxxxxx
    scheme https
</match>

Expected Behavior or What you need to ask

When I use this plugin to connect to aws opensearch, after a few days, I get this error in the logs

failed to flush the buffer. retry_times=14 next_retry_time=2022-11-22 05:43:24 +0000 chunk="5edfeac22ba712f91bf039046796ec61" error_class=Fluent::Plugin::OpenSearchOutput::RecoverableRequestFailure error="could not push logs to OpenSearch cluster ({:host=>"XXXXXXXX", :port=>443, :scheme=>"https", :user=>"XXXXXXXX", :password=>"XXXXXXXX"}): Cannot get new connection from pool.

Using Fluentd and OpenSearch plugin versions

• Ubuntu 11.2.0-19ubuntu1
• Bare Metal or within Docker or Kubernetes or others?
• td-agent 4.4.1 fluentd 1.15.2
• fluent-plugin-opensearch (1.0.8)
• OpenSearch 1.3
• OpenSearch template(s) (optional)

[haobin-ihealth]

I think it may be because the connection has suspended animation for a long time without writing, and a new connection will be applied for when writing again, causing the connection to be exhausted. Now as the frequency of the records I write becomes higher, there is no longer a situation where the link cannot be obtained.