fish.payara.microprofile.metrics

Interface MetricsService

All Known Implementing Classes:

MetricsServiceImpl

@Contract
public interface MetricsService

The API to use MetricRegistrys within an multi-application environment. The main purpose of this API is to cleanly decouple the users from the service provider and to avoid API pollution with methods that might be added to test or integrate the implementation but should not be called anywhere else.

Since:

5.2020.8

Author:

Jan Bernitt

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	MetricsService.MetricsContext Each deployed application has its own MetricsService.MetricsContext.

Method Summary

Modifier and Type	Method and Description
MetricsService.MetricsContext	getContext(boolean createIfNotExists) Access current application metric context.
MetricsService.MetricsContext	getContext(String name) Access the context by name.
Set<String>	getContextNames()
boolean	isEnabled() When metrics are disabled no MetricsService.MetricsContext exists, both getContext(boolean) and getContext(String) will return null.
void	refresh() Triggers update of internal state usually used after configuration changes that can have the effect that metrics appear or disappear in a way that is detected by the registry.

Method Detail

isEnabled

boolean isEnabled()

When metrics are disabled no MetricsService.MetricsContext exists, both getContext(boolean) and getContext(String) will return null.

Returns:

true if the metrics feature is generally enabled, else false

refresh

void refresh()

Triggers update of internal state usually used after configuration changes that can have the effect that metrics appear or disappear in a way that is detected by the registry.

getContextNames

Set<String> getContextNames()

Returns:

a set of all MetricsService.MetricsContext that currently exist. When applications are undeployed their MetricsService.MetricsContext equally are removed which means a name from the set of names returned may indeed no longer exists when using getContext(boolean).

getContext

MetricsService.MetricsContext getContext(boolean createIfNotExists)

Access current application metric context. If this is called from a context that is not linked to an application context the server context is returned.

Parameters:

createIfNotExists - true to create the requested context in case it did not exist, false to instead return null in that case

Returns:

the existing or created context or null if it did not exist and parameter was false or if the servicenot isEnabled()

getContext

MetricsService.MetricsContext getContext(String name)

Access the context by name. Implicitly creates the MetricsService.MetricsContext.SERVER_CONTEXT_NAME if needed but no other context that does not exist yet or no more.

Parameters:

name - the name of the MetricsService.MetricsContext to provide, this assumes it does exist

Returns:

the existing context or null if it does not (or no longer) exist. When the service not isEnabled() no context exists. Otherwise when asking for the MetricsService.MetricsContext.SERVER_CONTEXT_NAME the context is created should it not exist yet.