org.apache.ambari.server.controller.metrics

Class ThreadPoolEnabledPropertyProvider

java.lang.Object

org.apache.ambari.server.controller.internal.BaseProvider

org.apache.ambari.server.controller.internal.AbstractPropertyProvider

org.apache.ambari.server.controller.metrics.ThreadPoolEnabledPropertyProvider

All Implemented Interfaces:

PropertyProvider

Direct Known Subclasses:

JMXPropertyProvider, RestMetricsPropertyProvider

public abstract class ThreadPoolEnabledPropertyProvider
extends AbstractPropertyProvider

Unites common functionality for multithreaded metrics providers (JMX and REST as of now). Shares the same pool of executor threads across all implementations.

This PropertyProvider should not be mistaken for a way to perform expensive operations, as it is still called as part of the incoming REST Jetty request. It is poor design to have UI threads from the web client waiting on expensive operations from a PropertyProvider, even if they are spread across multiple threads.

Instead, this PropertyProvider is useful for spreading many small, quick operations across a threadpool. This is why the known implementations of this class (such as the JMXPropertyProvider) use a cache instead of reaching out to network endpoints on their own.

This is also why the ThreadPoolExecutor used here has an unbounded worker queue and essentially a fixed core size to perform its work. When Callables are rejected because of a worker queue exhaustion, they are never submitted for execution, yet the Future instance is still returned. Therefore, if the queue is ever exhausted, incoming REST API requests must wait the entire CompletionService.poll(long, TimeUnit) timeout before skipping the result and returning control.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	ThreadPoolEnabledPropertyProvider.Ticket Ticket used to cancel provider threads.

Field Summary

Fields

Modifier and Type	Field and Description
static Set<String>	healthyStates Host states that make available metrics collection
protected String	hostNamePropertyId

Constructor Summary

Constructors

Constructor and Description
ThreadPoolEnabledPropertyProvider(Map<String,Map<String,PropertyInfo>> componentMetrics, String hostNamePropertyId, MetricHostProvider metricHostProvider, String clusterNamePropertyId) Construct a provider.

Method Summary

Modifier and Type	Method and Description
protected static String	getCacheKeyForException(Throwable throwable)
String	getHost(Resource resource, String clusterName, String componentName) Returns a hostname for component
protected String	getSpec(String protocol, String hostName, String port, String url) Get complete URL from parts
static void	init(Configuration configuration)
protected static boolean	isRequestedPropertyId(String propertyId, String requestedPropertyId, Request request) Determine whether or not the given property id was requested.
protected static String	logException(Throwable throwable) Log an error for the given exception.
protected abstract Resource	populateResource(Resource resource, Request request, Predicate predicate, ThreadPoolEnabledPropertyProvider.Ticket ticket) Populate a resource by obtaining the requested JMX properties.
Set<Resource>	populateResources(Set<Resource> resources, Request request, Predicate predicate) Populate the given set of resource with any properties that this property provider can provide and return a populated set of resources.
protected static void	rethrowSystemException(Throwable throwable) Rethrow the given exception as a System exception and log the message.
protected void	setPopulateTimeout(long populateTimeout) Set the populate timeout value for this provider.

Methods inherited from class org.apache.ambari.server.controller.internal.AbstractPropertyProvider

checkAuthorizationForMetrics, checkPropertyCategory, getClustersNameFromResources, getClustersResourceId, getComponentMetrics, getPropertyInfoMap, getResourceTypeFromResources, getValue, isSupportedPropertyId, substituteArgument, updateComponentMetricMap, updatePropertyInfo, updatePropertyInfoMap

Methods inherited from class org.apache.ambari.server.controller.internal.BaseProvider

checkCategory, checkConfigPropertyIds, checkPropertyIds, containsArguments, getCategoryIds, getPropertyIds, getRegexEntry, getRegexGroups, getRequestPropertyIds, isPatternKey, isPropertyCategoryRequested, isPropertyEntryRequested, isPropertyRequested, setResourceProperty

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.ambari.server.controller.spi.PropertyProvider

checkPropertyIds

Field Detail

healthyStates

public static final Set<String> healthyStates

Host states that make available metrics collection

hostNamePropertyId

protected final String hostNamePropertyId

Constructor Detail

ThreadPoolEnabledPropertyProvider

public ThreadPoolEnabledPropertyProvider(Map<String,Map<String,PropertyInfo>> componentMetrics,
                                         String hostNamePropertyId,
                                         MetricHostProvider metricHostProvider,
                                         String clusterNamePropertyId)

Construct a provider.

Parameters:

componentMetrics - map of metrics for this provider

Method Detail

init

@Inject
public static void init(Configuration configuration)

populateResources

public Set<Resource> populateResources(Set<Resource> resources,
                                       Request request,
                                       Predicate predicate)
                                throws SystemException

Description copied from interface: PropertyProvider

Populate the given set of resource with any properties that this property provider can provide and return a populated set of resources. The provider may drop resources from the original set if it determines that the don't meet the conditions of the predicate.

Parameters:

resources - the resources to be populated

request - the request object which defines the desired set of properties

predicate - the predicate object which filters which resources are returned

Returns:

the populated set of resources

Throws:

SystemException - thrown if resources cannot be populated

populateResource

protected abstract Resource populateResource(Resource resource,
                                             Request request,
                                             Predicate predicate,
                                             ThreadPoolEnabledPropertyProvider.Ticket ticket)
                                      throws SystemException

Populate a resource by obtaining the requested JMX properties.

Parameters:

resource - the resource to be populated

request - the request

predicate - the predicate

Returns:

the populated resource; null if the resource should NOT be part of the result set for the given predicate

Throws:

SystemException

setPopulateTimeout

protected void setPopulateTimeout(long populateTimeout)

Set the populate timeout value for this provider.

Parameters:

populateTimeout - the populate timeout value

isRequestedPropertyId

protected static boolean isRequestedPropertyId(String propertyId,
                                               String requestedPropertyId,
                                               Request request)

Determine whether or not the given property id was requested.

getCacheKeyForException

protected static String getCacheKeyForException(Throwable throwable)

logException

protected static String logException(Throwable throwable)

Log an error for the given exception.

Parameters:

throwable - the caught exception

Returns:

the error message that was logged

rethrowSystemException

protected static void rethrowSystemException(Throwable throwable)
                                      throws SystemException

Rethrow the given exception as a System exception and log the message.

Parameters:

throwable - the caught exception

Throws:

SystemException - always around the given exception

getHost

public String getHost(Resource resource,
                      String clusterName,
                      String componentName)
               throws SystemException

Returns a hostname for component

Throws:

SystemException

getSpec

protected String getSpec(String protocol,
                         String hostName,
                         String port,
                         String url)

Get complete URL from parts