[opensearchserverless] Add support for monitoring OpenSearch Serverless

[ajay340]

Feature scope

Opensearch Serverless

Describe your suggested feature

cdk-monitoring-constructs currently supports monitoring Opensearch and Elasticsearch clusters, but not Opensearch serverless. I am requesting you add support to monitor an Opensearch serverless.

[dhanushuUzumaki]

Hi, I'd like to work on this. On a high level, I am planning to add monitorOpenSearchServerlessCollection to facade. With following metrics and alarm support on these metrics. Since OCU is on account level, I am also considering having a boolean param to specify whether to include OCU metrics as part of this segment instance.

• IngestionDocumentErrors
• IngestionRequestErrors
• IngestionRequestLatency
• SearchRequestErrors
• SearchRequestLatency
• StorageUsedInS3
• IndexingOCU
• SearchOCU

[echeung-amzn]

Since OCU is on account level, I am also considering having a boolean param to specify whether to include OCU metrics as part of this segment instance.

It'd probably make more sense to separate it such that there's monitorOpenSearchServerlessCollection that monitors a collection and something like monitorOpenSearchServerless that monitors higher-level metrics that aren't at a collection/instance level.

[dhanushuUzumaki]

That makes sense. I will start with monitorOpenSearchServerless for metrics on account level. IndexingOCU and SearchOCU