org.apache.ambari.server.controller.logging

Class LogSearchDataRetrievalService

java.lang.Object

com.google.common.util.concurrent.AbstractService

org.apache.ambari.server.controller.logging.LogSearchDataRetrievalService

All Implemented Interfaces:

com.google.common.util.concurrent.Service

public class LogSearchDataRetrievalService
extends com.google.common.util.concurrent.AbstractService

The LogSearchDataRetrievalService is an Ambari Service that is used by the Ambari LogSearch integration code to obtain response data from the LogSearch server. In order to improve the performance of the LogSearch integration layer in Ambari, this service implements the following:

• A cache for LogSearch data that typically is returned by the LogSearch REST API
• Implements the remote request for LogSearch data not found in the cache on a separate thread, which keeps the request from affecting the overall performance of the Ambari REST API

As with other services annotated with AmbariService, this class may be injected in order to obtain cached access to the LogSearch responses. Caches are initially empty in this implementation, and a remote request to the LogSearch server will be made upon the first request for a given response.

Nested Class Summary

Nested classes/interfaces inherited from interface com.google.common.util.concurrent.Service

com.google.common.util.concurrent.Service.Listener, com.google.common.util.concurrent.Service.State

Constructor Summary

Constructors

Constructor and Description
LogSearchDataRetrievalService()

Method Summary

Modifier and Type	Method and Description
protected void	doStart()
protected void	doStop()
protected Map<String,AtomicInteger>	getComponentRequestFailureCounts() This protected method allows for simpler unit tests.
protected Set<String>	getCurrentRequests() This protected method allows for simpler unit tests.
Set<String>	getLogFileNames(String component, String host, String cluster) This method attempts to obtain the log file names for the specified component on the specified host.
String	getLogFileTailURI(String baseURI, String component, String host, String cluster)
protected void	setExecutor(Executor executor) This protected method provides a way for unit-tests to insert a mock executor for simpler unit-testing.
protected void	setLoggingRequestHelperFactory(LoggingRequestHelperFactory loggingRequestHelperFactory)

Methods inherited from class com.google.common.util.concurrent.AbstractService

addListener, awaitRunning, awaitRunning, awaitTerminated, awaitTerminated, failureCause, isRunning, notifyFailed, notifyStarted, notifyStopped, startAsync, state, stopAsync, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

LogSearchDataRetrievalService

public LogSearchDataRetrievalService()

Method Detail

doStart

protected void doStart()

Specified by:

doStart in class com.google.common.util.concurrent.AbstractService

doStop

protected void doStop()

Specified by:

doStop in class com.google.common.util.concurrent.AbstractService

getLogFileNames

public Set<String> getLogFileNames(String component,
                                   String host,
                                   String cluster)

This method attempts to obtain the log file names for the specified component on the specified host. A cache lookup is first attempted. If the cache does not contain this data, an asynchronous task is launched in order to make the REST request to the LogSearch server to obtain this data. Once the data is available in the cache, subsequent calls for a given Host/Component combination should return non-null.

Parameters:

component - the component name

host - the host name

cluster - the cluster name

Returns:

a Set that includes the log file names associated with this Host/Component combination, or null if that object does not exist in the cache.

getLogFileTailURI

public String getLogFileTailURI(String baseURI,
                                String component,
                                String host,
                                String cluster)

setLoggingRequestHelperFactory

protected void setLoggingRequestHelperFactory(LoggingRequestHelperFactory loggingRequestHelperFactory)

setExecutor

protected void setExecutor(Executor executor)

This protected method provides a way for unit-tests to insert a mock executor for simpler unit-testing.

Parameters:

executor - an Executor instance

getCurrentRequests

protected Set<String> getCurrentRequests()

This protected method allows for simpler unit tests.

Returns:

the Set of current Requests that are not yet completed

getComponentRequestFailureCounts

protected Map<String,AtomicInteger> getComponentRequestFailureCounts()

This protected method allows for simpler unit tests.

Returns:

the Map of failure counts on a per-component basis