Micrometer configuration lifecycle violation

[jonatan-ivanov]

Micrometer's MeterRegistry should be "configured" (see MeterRegistry.Config) before registering Meter instances to it. For example MeterFilters should be configured before a Meter has been registered to the registry.

Historically, Micrometer has allowed configuring MeterFilters after meters have been registered but due to certain performance optimizations with micrometer-metrics/micrometer#4917 we took a step toward warning users about this situation.

See:

• MeterFilters configured after a Meter has been registered micrometer-metrics/micrometer#4920
• Warn when a MeterFilter is configured after a meter is registered micrometer-metrics/micrometer#4917

It seems in certain cases Vert.x configures a MeterFilter after a Meter has been registered to the registry causing the warning mentioned above. See micrometer-metrics/micrometer#4920 (comment) by @sanyarnd with a reproducer.

@sanyarnd could you please provide the Vert.x version you are using and any additional details you have?

[tsegismont]

I'll look into it

[tsegismont]

I read the logs in the comment posted by @sanyarnd in micrometer-metrics/micrometer#4920

The warning is logged when the Vert.x Metrics instance is created. No meter is registered by Vert.x at this stage. Users must either:

• delay meters registration until Vert.x has set up its Metrics instance, or
• enable all labels (MicrometerMetricsOptions#setLabels) and configure no matcher (with MicrometerMetricsOptions addLabelMatch)

Feel free to reach out if more info is needed

[jonatan-ivanov]

@tsegismont Is there a way to guide the users towards how to register heir own Meters at startup? E.g.: a section in the docs?

[tsegismont]

@jonatan-ivanov I don't believe we should document how to register their own meters, the Micrometer doc is does it well. But thanks for mentioning docs, I think it would be nice to have a note that explains that Vert.x can register meter filters and, for this reason, they can see Micrometer's warning in the logs.

[tsegismont]

Closed by caca2d7