HealthChecksSupport
org.scalatra.metrics.HealthChecksSupport
trait HealthChecksSupport extends CheckedBuilder, MetricsBootstrap
Attributes
- Graph
-
- Supertypes
-
trait MetricsBootstraptrait CheckedBuildertrait BaseBuilderclass Objecttrait Matchableclass AnyShow all
Members list
Value members
Concrete methods
def checkHealth[T](name: String)(checker: => T)(implicit toMagnet: ByName[T] => HealthCheckMagnet): HealthCheck
def checkHealth[T](name: String, unhealthyMessage: String)(checker: => T)(implicit toMagnet: ByName[T] => HealthCheckMagnet): HealthCheck
Inherited methods
def healthCheck[T](name: String, unhealthyMessage: String)(checker: => T)(implicit toMagnet: ByName[T] => HealthCheckMagnet): HealthCheck
Converts a code block to a com.codahale.metrics.health.HealthCheck and registers it.
Converts a code block to a com.codahale.metrics.health.HealthCheck and registers it.
Use it as follows:
object Application {
// The application wide health check registry.
val healthCheckRegistry = new com.codahale.metrics.health.HealthCheckRegistry()
}
trait Checked extends CheckedBuilder {
val registry = Application.healthCheckRegistry
}
class ExampleWorker extends Checked {
healthCheck("alive") { workerThreadIsActive() }
}
The code block must have a result of type Boolean
, Try
, Either
, Future
, com.codahale.metrics.health.HealthCheck.Result, or Unit
.
- A check result of
true
indicates healthy,false
indicates unhealthy. - A check result of type Success indicates healthy, Failure indicates unhealthy. The embedded value (after applying
.toString
) or throwable is used as (un)healthy message. - A check result of type Future will have 3 seconds to execute (by default). The result of the execution will be treated as Success or Failure.
- A check result of type Right indicates healthy, Left
[Any]
or Left[Throwable]
indicates unhealthy. The embedded value (after applying.toString
) or throwable is used as (un)healthy message. - If the check result is of type com.codahale.metrics.health.HealthCheck.Result, the result is passed unchanged.
- A check result of type Unit indicates healthy.
- If a checker throws an exception, the result is considered unhealthy with the throwable as unhealthy message.
It is also possible to override the health check base name. For example:
class ExampleWorker extends Checked {
override lazy val metricBaseName = MetricName("Overridden.Base.Name")
healthCheck("alive") { workerThreadIsActive() }
}
To change the timeout for Future execution, set an implicit duration:
class ExampleWorker extends Checked {
implicit private val timeout = 10.seconds
healthCheck("alive")(Future { workerThreadIsActive() })
}
NOTE: only one health check can be registered under a name (including the base name, which is derived from the
class name by default). A common cause for multiple registrations is when a class that defines a health check is
instantiated multiple times. Since metrics-core 4.1.0 subsequent registrations lead to an exception. Earlier
versions silently ignore subsequent registrations.
@param name the name of the health check
@param unhealthyMessage the unhealthy message for checkers that return `false`, defaults to `"Health check failed"`
@param checker the code block that does the health check
Attributes
- Inherited from:
- CheckedBuilder
Concrete fields
The com.codahale.metrics.health.HealthCheckRegistry where created metrics are registered.
The com.codahale.metrics.health.HealthCheckRegistry where created metrics are registered.
Attributes
Inherited fields
The base name for all metrics created from this builder.
The base name for all metrics created from this builder.
Attributes
- Inherited from:
- BaseBuilder
Implicits
Inherited implicits
Attributes
- Inherited from:
- MetricsBootstrap
Attributes
- Inherited from:
- MetricsBootstrap
In this article