4.x Hikari CP connections creation metric units is ms, should be seconds

[tjquinno]

Environment Details

• Helidon Version: 4.x
• Helidon SE or Helidon MP
• JDK version:
• OS:
• Docker version (if applicable):

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Problem Description

See #8422 (comment) filed by @hyder (copied below for convenience)

hikari units are in milliseconds:

# TYPE hikaricp_connections_creation_milliseconds summary
hikaricp_connections_creation_milliseconds{mp_scope="vendor",pool="cloudbank",quantile="0.5",} 608.0

This is probably coming from the hikari lib itself. Would it be possible to submit a PR to hikari so it also uses seconds?

[tjquinno]

I suspect the HikariCP integration records various time values--connection creation among them--as milliseconds because that code uses MP metrics histograms to record the values and histograms accept updates of long or int.

One possibility could be to rewrite the Helidon MicroProfileMetricsTracker class in helidon-integrations-cdi-datasource-hikaricp to use the neutral Helidon SE metrics API, where updates can be applied to distribution summaries as double values.

In addition, to preserve the existing behavior we would probably need to add a config setting to control whether HikariCP-related times were recorded as ms or seconds.