software.amazon.jdbc.util.monitoring

Class MonitorServiceImpl

java.lang.Object

software.amazon.jdbc.util.monitoring.MonitorServiceImpl

All Implemented Interfaces:

EventSubscriber, MonitorService

public class MonitorServiceImpl
extends java.lang.Object
implements MonitorService, EventSubscriber

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	MonitorServiceImpl.CacheContainer A container that holds a cache of monitors of a given type with the related settings and info for that type.
protected static class	MonitorServiceImpl.MonitorItem A container object that holds a monitor together with the supplier used to generate the monitor.

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.concurrent.ScheduledExecutorService	cleanupExecutor
protected static long	DEFAULT_CLEANUP_INTERVAL_NANOS
protected static java.util.Map<java.lang.Class<? extends Monitor>,java.util.function.Supplier<MonitorServiceImpl.CacheContainer>>	defaultSuppliers
protected java.util.Map<java.lang.Class<? extends Monitor>,MonitorServiceImpl.CacheContainer>	monitorCaches
protected EventPublisher	publisher

Constructor Summary

Constructors

Constructor and Description
MonitorServiceImpl(EventPublisher publisher)
MonitorServiceImpl(long cleanupIntervalNanos, EventPublisher publisher) Constructs a MonitorServiceImpl instance, subscribes to the given publisher's data access events, and submits a cleanup thread to supervise submitted monitors.

Method Summary

Modifier and Type	Method and Description
protected void	checkMonitors()
<T extends Monitor> T	get(java.lang.Class<T> monitorClass, java.lang.Object key) Gets the monitor stored at the given key.
protected void	handleMonitorError(MonitorServiceImpl.CacheContainer cacheContainer, java.lang.Object key, MonitorServiceImpl.MonitorItem errorMonitorItem)
protected void	initCleanupThread(long cleanupIntervalNanos)
void	processEvent(Event event) Processes an event.
<T extends Monitor> void	registerMonitorTypeIfAbsent(java.lang.Class<T> monitorClass, long expirationTimeoutNanos, long heartbeatTimeoutNanos, java.util.Set<MonitorErrorResponse> errorResponses, @Nullable java.lang.Class<?> producedDataClass) Registers a new monitor type with the monitor service.
void	releaseResources() Releases any resources opened by the monitor service, stops all monitors, and removes all monitors from the monitor service.
<T extends Monitor> T	remove(java.lang.Class<T> monitorClass, java.lang.Object key) Removes the monitor stored at the given key.
<T extends Monitor> T	runIfAbsent(java.lang.Class<T> monitorClass, java.lang.Object key, StorageService storageService, TelemetryFactory telemetryFactory, java.lang.String originalUrl, java.lang.String driverProtocol, TargetDriverDialect driverDialect, Dialect dbDialect, java.util.Properties originalProps, MonitorInitializer initializer) Creates and starts the given monitor if it does not already exist and stores it under the given monitor type and key.
<T extends Monitor> void	stopAndRemove(java.lang.Class<T> monitorClass, java.lang.Object key) Stops the given monitor and removes it from the monitor service.
void	stopAndRemoveAll() Stops all monitors and removes them from the monitor service.
<T extends Monitor> void	stopAndRemoveMonitors(java.lang.Class<T> monitorClass) Stops all monitors for the given type and removes them from the monitor service.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_CLEANUP_INTERVAL_NANOS

protected static final long DEFAULT_CLEANUP_INTERVAL_NANOS

defaultSuppliers

protected static final java.util.Map<java.lang.Class<? extends Monitor>,java.util.function.Supplier<MonitorServiceImpl.CacheContainer>> defaultSuppliers

publisher

protected final EventPublisher publisher

monitorCaches

protected final java.util.Map<java.lang.Class<? extends Monitor>,MonitorServiceImpl.CacheContainer> monitorCaches

cleanupExecutor

protected final java.util.concurrent.ScheduledExecutorService cleanupExecutor

Constructor Detail

MonitorServiceImpl

public MonitorServiceImpl(EventPublisher publisher)

MonitorServiceImpl

public MonitorServiceImpl(long cleanupIntervalNanos,
                          EventPublisher publisher)

Constructs a MonitorServiceImpl instance, subscribes to the given publisher's data access events, and submits a cleanup thread to supervise submitted monitors.

Parameters:

cleanupIntervalNanos - the interval at which the cleanup thread should check on submitted monitors, in nanoseconds.

publisher - the publisher to subscribe to for data access events.

Method Detail

initCleanupThread

protected void initCleanupThread(long cleanupIntervalNanos)

checkMonitors

protected void checkMonitors()

handleMonitorError

protected void handleMonitorError(MonitorServiceImpl.CacheContainer cacheContainer,
                                  java.lang.Object key,
                                  MonitorServiceImpl.MonitorItem errorMonitorItem)

registerMonitorTypeIfAbsent

public <T extends Monitor> void registerMonitorTypeIfAbsent(java.lang.Class<T> monitorClass,
                                                            long expirationTimeoutNanos,
                                                            long heartbeatTimeoutNanos,
                                                            java.util.Set<MonitorErrorResponse> errorResponses,
                                                            @Nullable java.lang.Class<?> producedDataClass)

Description copied from interface: MonitorService

Registers a new monitor type with the monitor service. This method needs to be called before adding new types of monitors to the monitor service, so that the monitor service knows when to dispose of a monitor. Expected monitor types will be added automatically during driver initialization, but this method can be called by users if they want to add a new monitor type.

Specified by:

registerMonitorTypeIfAbsent in interface MonitorService

Type Parameters:

T - the type of the monitor.

Parameters:

monitorClass - the class of the monitor, eg `CustomEndpointMonitorImpl.class`.

expirationTimeoutNanos - how long a monitor should be stored without use before being considered expired, in nanoseconds. Expired monitors may be removed and stopped.

heartbeatTimeoutNanos - a duration in nanoseconds defining the maximum amount of time that a monitor should take between updating its last-updated timestamp. If a monitor has not updated its last-updated timestamp within this duration it will be considered stuck.

errorResponses - a Set defining actions to take if the monitor is stuck or in an error state.

producedDataClass - the class of data produced by the monitor.

runIfAbsent

public <T extends Monitor> T runIfAbsent(java.lang.Class<T> monitorClass,
                                         java.lang.Object key,
                                         StorageService storageService,
                                         TelemetryFactory telemetryFactory,
                                         java.lang.String originalUrl,
                                         java.lang.String driverProtocol,
                                         TargetDriverDialect driverDialect,
                                         Dialect dbDialect,
                                         java.util.Properties originalProps,
                                         MonitorInitializer initializer)
                                  throws java.sql.SQLException

Description copied from interface: MonitorService

Creates and starts the given monitor if it does not already exist and stores it under the given monitor type and key. If the monitor already exists, its expiration time will be renewed, even if it was already expired.

Specified by:

runIfAbsent in interface MonitorService

Type Parameters:

T - the type of the monitor.

Parameters:

monitorClass - the concrete class of the monitor, eg `CustomEndpointMonitorImpl.class`.

key - the key for the monitor, eg "custom-endpoint.cluster-custom-XYZ.us-east-2.rds.amazonaws.com:5432".

storageService - the storage service for the monitor to use.

telemetryFactory - the telemetry factory for creating telemetry data.

originalUrl - the URL of the original database connection.

driverProtocol - the protocol for the underlying target driver.

driverDialect - the target driver dialect.

dbDialect - the database dialect.

originalProps - the properties of the original database connection.

initializer - an initializer function to use to create the monitor if it does not already exist.

Returns:

the new or existing monitor.

Throws:

java.sql.SQLException - if an error occurs while trying to create the monitor.

get

public <T extends Monitor> T get(java.lang.Class<T> monitorClass,
                                 java.lang.Object key)

Description copied from interface: MonitorService

Gets the monitor stored at the given key.

Specified by:

get in interface MonitorService

Type Parameters:

T - the type of the monitor.

Parameters:

monitorClass - the expected class of the monitor.

key - the key for the monitor.

Returns:

the monitor stored at the given key.

remove

public <T extends Monitor> T remove(java.lang.Class<T> monitorClass,
                                    java.lang.Object key)

Description copied from interface: MonitorService

Removes the monitor stored at the given key. If the expected monitor class does not match the actual monitor class no action will be performed.

Specified by:

remove in interface MonitorService

Type Parameters:

T - the type of the monitor.

Parameters:

monitorClass - the expected class of the monitor.

key - the key for the monitor.

Returns:

the monitor that was removed. Returns null if there was no monitor at the given key or the expected monitor class did not match the actual monitor class.

stopAndRemove

public <T extends Monitor> void stopAndRemove(java.lang.Class<T> monitorClass,
                                              java.lang.Object key)

Description copied from interface: MonitorService

Stops the given monitor and removes it from the monitor service.

Specified by:

stopAndRemove in interface MonitorService

Type Parameters:

T - the type of the monitor.

Parameters:

monitorClass - the class of the monitor, eg `CustomEndpointMonitorImpl.class`.

key - the key for the monitor, eg "custom-endpoint.cluster-custom-XYZ.us-east-2.rds.amazonaws.com:5432".

stopAndRemoveMonitors

public <T extends Monitor> void stopAndRemoveMonitors(java.lang.Class<T> monitorClass)

Description copied from interface: MonitorService

Stops all monitors for the given type and removes them from the monitor service.

Specified by:

stopAndRemoveMonitors in interface MonitorService

Type Parameters:

T - the type of the monitor.

Parameters:

monitorClass - the class of the monitor, eg `CustomEndpointMonitorImpl.class`.

stopAndRemoveAll

public void stopAndRemoveAll()

Description copied from interface: MonitorService

Stops all monitors and removes them from the monitor service.

Specified by:

stopAndRemoveAll in interface MonitorService

releaseResources

public void releaseResources()

Description copied from interface: MonitorService

Releases any resources opened by the monitor service, stops all monitors, and removes all monitors from the monitor service.

Specified by:

releaseResources in interface MonitorService

processEvent

public void processEvent(Event event)

Description copied from interface: EventSubscriber

Processes an event. This method will only be called on this subscriber if it has subscribed to the event class via EventPublisher.subscribe(software.amazon.jdbc.util.events.EventSubscriber, java.util.Set<java.lang.Class<? extends software.amazon.jdbc.util.events.Event>>).

Specified by:

processEvent in interface EventSubscriber

Parameters:

event - the event to process.