DecayRpcScheduler (Apache Hadoop Common 3.4.1.300-dep-1001 API)

java.lang.Object
- org.apache.hadoop.ipc.DecayRpcScheduler

All Implemented Interfaces:

DecayRpcSchedulerMXBean, RpcScheduler, MetricsSource
```
public class DecayRpcScheduler
extends java.lang.Object
implements RpcScheduler, DecayRpcSchedulerMXBean, MetricsSource
```
The decay RPC scheduler tracks the cost of incoming requests in a map, then decays the costs at a fixed time interval. The scheduler is optimized for large periods (on the order of seconds), as it offloads work to the decay sweep.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`static class`	`DecayRpcScheduler.DecayTask`	This TimerTask will call decayCurrentCosts until the scheduler has been garbage collected.
`static class`	`DecayRpcScheduler.MetricsProxy`	MetricsProxy is a singleton because we may init multiple schedulers and we want to clean up resources when a new scheduler replaces the old one.

Field Summary

Fields
Modifier and Type	Field	Description
`static java.lang.String`	`DECAYSCHEDULER_METRICS_TOP_USER_COUNT`
`static int`	`DECAYSCHEDULER_METRICS_TOP_USER_COUNT_DEFAULT`
`static java.lang.String`	`DECAYSCHEDULER_UNKNOWN_IDENTITY`
`static java.lang.Boolean`	`IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_ENABLE_DEFAULT`
`static java.lang.String`	`IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_ENABLE_KEY`
`static java.lang.String`	`IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_THRESHOLDS_KEY`
`static java.lang.String`	`IPC_DECAYSCHEDULER_SERVICE_USERS_KEY`	Service users will always be scheduled into the highest-priority queue.
`static java.lang.String`	`IPC_DECAYSCHEDULER_THRESHOLDS_KEY`	Thresholds are specified as integer percentages, and specify which usage range each queue will be allocated to.
`static java.lang.String`	`IPC_FCQ_DECAYSCHEDULER_FACTOR_KEY`	Deprecated.
`static java.lang.String`	`IPC_FCQ_DECAYSCHEDULER_PERIOD_KEY`	Deprecated.
`static java.lang.String`	`IPC_FCQ_DECAYSCHEDULER_THRESHOLDS_KEY`	Deprecated.
`static double`	`IPC_SCHEDULER_DECAYSCHEDULER_FACTOR_DEFAULT`
`static java.lang.String`	`IPC_SCHEDULER_DECAYSCHEDULER_FACTOR_KEY`	Decay factor controls how much each cost is suppressed by on each sweep.
`static long`	`IPC_SCHEDULER_DECAYSCHEDULER_PERIOD_DEFAULT`
`static java.lang.String`	`IPC_SCHEDULER_DECAYSCHEDULER_PERIOD_KEY`	Period controls how many milliseconds between each decay sweep.
`static org.slf4j.Logger`	`LOG`

Constructor Summary

Constructors
Constructor Description

DecayRpcScheduler(int numLevels, java.lang.String ns, Configuration conf)
Create a decay scheduler.

Constructors
Constructor	Description
`DecayRpcScheduler(int numLevels, java.lang.String ns, Configuration conf)`	Create a decay scheduler.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`addResponseTime(java.lang.String callName, Schedulable schedulable, ProcessingDetails details)`	Store a processing time value for an RPC call into this scheduler.
`double[]`	`getAverageResponseTime()`
`java.lang.String`	`getCallVolumeSummary()`
`DecayRpcSchedulerDetailedMetrics`	`getDecayRpcSchedulerDetailedMetrics()`
`void`	`getMetrics(MetricsCollector collector, boolean all)`	Get metrics from the metrics source
`int`	`getPriorityLevel(Schedulable obj)`	Compute the appropriate priority for a schedulable based on past requests.
`long[]`	`getResponseTimeCountInLastWindow()`
`java.lang.String`	`getSchedulingDecisionSummary()`
`long`	`getTotalCallVolume()`
`long`	`getTotalRawCallVolume()`
`long`	`getTotalServiceUserCallVolume()`
`long`	`getTotalServiceUserRawCallVolume()`
`int`	`getUniqueIdentityCount()`
`boolean`	`shouldBackOff(Schedulable obj)`
`void`	`stop()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.hadoop.ipc.RpcScheduler
addResponseTime

- Field Detail
  - IPC_SCHEDULER_DECAYSCHEDULER_PERIOD_KEY
```
public static final java.lang.String IPC_SCHEDULER_DECAYSCHEDULER_PERIOD_KEY
```
    Period controls how many milliseconds between each decay sweep.
    
    See Also:
    
    Constant Field Values
  - IPC_SCHEDULER_DECAYSCHEDULER_PERIOD_DEFAULT
```
public static final long IPC_SCHEDULER_DECAYSCHEDULER_PERIOD_DEFAULT
```
    See Also:
    
    Constant Field Values
  - IPC_FCQ_DECAYSCHEDULER_PERIOD_KEY
```
@Deprecated
public static final java.lang.String IPC_FCQ_DECAYSCHEDULER_PERIOD_KEY
```
    Deprecated.
    
    See Also:
    
    Constant Field Values
  - IPC_SCHEDULER_DECAYSCHEDULER_FACTOR_KEY
```
public static final java.lang.String IPC_SCHEDULER_DECAYSCHEDULER_FACTOR_KEY
```
    Decay factor controls how much each cost is suppressed by on each sweep. Valid numbers are > 0 and < 1. Decay factor works in tandem with period to control how long the scheduler remembers an identity.
    
    See Also:
    
    Constant Field Values
  - IPC_SCHEDULER_DECAYSCHEDULER_FACTOR_DEFAULT
```
public static final double IPC_SCHEDULER_DECAYSCHEDULER_FACTOR_DEFAULT
```
    See Also:
    
    Constant Field Values
  - IPC_FCQ_DECAYSCHEDULER_FACTOR_KEY
```
@Deprecated
public static final java.lang.String IPC_FCQ_DECAYSCHEDULER_FACTOR_KEY
```
    Deprecated.
    
    See Also:
    
    Constant Field Values
  - IPC_DECAYSCHEDULER_THRESHOLDS_KEY
```
public static final java.lang.String IPC_DECAYSCHEDULER_THRESHOLDS_KEY
```
    Thresholds are specified as integer percentages, and specify which usage range each queue will be allocated to. For instance, specifying the list 10, 40, 80 implies 4 queues, with - q3 from 80% up - q2 from 40 up to 80 - q1 from 10 up to 40 - q0 otherwise.
    
    See Also:
    
    Constant Field Values
  - IPC_FCQ_DECAYSCHEDULER_THRESHOLDS_KEY
```
@Deprecated
public static final java.lang.String IPC_FCQ_DECAYSCHEDULER_THRESHOLDS_KEY
```
    Deprecated.
    
    See Also:
    
    Constant Field Values
  - IPC_DECAYSCHEDULER_SERVICE_USERS_KEY
```
public static final java.lang.String IPC_DECAYSCHEDULER_SERVICE_USERS_KEY
```
    Service users will always be scheduled into the highest-priority queue. They are specified as a comma-separated list.
    
    See Also:
    
    Constant Field Values
  - DECAYSCHEDULER_UNKNOWN_IDENTITY
```
public static final java.lang.String DECAYSCHEDULER_UNKNOWN_IDENTITY
```
    See Also:
    
    Constant Field Values
  - IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_ENABLE_KEY
```
public static final java.lang.String IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_ENABLE_KEY
```
    See Also:
    
    Constant Field Values
  - IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_ENABLE_DEFAULT
```
public static final java.lang.Boolean IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_ENABLE_DEFAULT
```
  - IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_THRESHOLDS_KEY
```
public static final java.lang.String IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_THRESHOLDS_KEY
```
    See Also:
    
    Constant Field Values
  - DECAYSCHEDULER_METRICS_TOP_USER_COUNT
```
public static final java.lang.String DECAYSCHEDULER_METRICS_TOP_USER_COUNT
```
    See Also:
    
    Constant Field Values
  - DECAYSCHEDULER_METRICS_TOP_USER_COUNT_DEFAULT
```
public static final int DECAYSCHEDULER_METRICS_TOP_USER_COUNT_DEFAULT
```
    See Also:
    
    Constant Field Values
  - LOG
```
public static final org.slf4j.Logger LOG
```
- Constructor Detail
  - DecayRpcScheduler
```
public DecayRpcScheduler(int numLevels,
                         java.lang.String ns,
                         Configuration conf)
```
    Create a decay scheduler.
    
    Parameters:
    
    numLevels - number of priority levels
    
    ns - config prefix, so that we can configure multiple schedulers in a single instance.
    
    conf - configuration to use.
- Method Detail
  - getPriorityLevel
```
public int getPriorityLevel(Schedulable obj)
```
    Compute the appropriate priority for a schedulable based on past requests.
    
    Specified by:
    
    getPriorityLevel in interface RpcScheduler
    
    Parameters:
    
    obj - the schedulable obj to query and remember
    
    Returns:
    
    the level index which we recommend scheduling in
  - shouldBackOff
```
public boolean shouldBackOff(Schedulable obj)
```
    Specified by:
    
    shouldBackOff in interface RpcScheduler
  - addResponseTime
```
public void addResponseTime(java.lang.String callName,
                            Schedulable schedulable,
                            ProcessingDetails details)
```
    Description copied from interface: RpcScheduler
    
    Store a processing time value for an RPC call into this scheduler.
    
    Specified by:
    
    addResponseTime in interface RpcScheduler
    
    Parameters:
    
    callName - The name of the call.
    
    schedulable - The schedulable representing the incoming call.
    
    details - The details of processing time.
  - getUniqueIdentityCount
```
public int getUniqueIdentityCount()
```
    Specified by:
    
    getUniqueIdentityCount in interface DecayRpcSchedulerMXBean
  - getTotalCallVolume
```
public long getTotalCallVolume()
```
    Specified by:
    
    getTotalCallVolume in interface DecayRpcSchedulerMXBean
  - getTotalRawCallVolume
```
public long getTotalRawCallVolume()
```
  - getTotalServiceUserCallVolume
```
public long getTotalServiceUserCallVolume()
```
  - getTotalServiceUserRawCallVolume
```
public long getTotalServiceUserRawCallVolume()
```
  - getResponseTimeCountInLastWindow
```
public long[] getResponseTimeCountInLastWindow()
```
    Specified by:
    
    getResponseTimeCountInLastWindow in interface DecayRpcSchedulerMXBean
  - getAverageResponseTime
```
public double[] getAverageResponseTime()
```
    Specified by:
    
    getAverageResponseTime in interface DecayRpcSchedulerMXBean
  - getMetrics
```
public void getMetrics(MetricsCollector collector,
                       boolean all)
```
    Description copied from interface: MetricsSource
    
    Get metrics from the metrics source
    
    Specified by:
    
    getMetrics in interface MetricsSource
    
    Parameters:
    
    collector - to contain the resulting metrics snapshot
    
    all - if true, return all metrics even if unchanged.
  - getSchedulingDecisionSummary
```
public java.lang.String getSchedulingDecisionSummary()
```
    Specified by:
    
    getSchedulingDecisionSummary in interface DecayRpcSchedulerMXBean
  - getCallVolumeSummary
```
public java.lang.String getCallVolumeSummary()
```
    Specified by:
    
    getCallVolumeSummary in interface DecayRpcSchedulerMXBean
  - getDecayRpcSchedulerDetailedMetrics
```
@VisibleForTesting
public DecayRpcSchedulerDetailedMetrics getDecayRpcSchedulerDetailedMetrics()
```
  - stop
```
public void stop()
```
    Specified by:
    
    stop in interface RpcScheduler

Class DecayRpcScheduler

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface org.apache.hadoop.ipc.RpcScheduler

Field Detail

IPC_SCHEDULER_DECAYSCHEDULER_PERIOD_KEY

IPC_SCHEDULER_DECAYSCHEDULER_PERIOD_DEFAULT

IPC_FCQ_DECAYSCHEDULER_PERIOD_KEY

IPC_SCHEDULER_DECAYSCHEDULER_FACTOR_KEY

IPC_SCHEDULER_DECAYSCHEDULER_FACTOR_DEFAULT

IPC_FCQ_DECAYSCHEDULER_FACTOR_KEY

IPC_DECAYSCHEDULER_THRESHOLDS_KEY

IPC_FCQ_DECAYSCHEDULER_THRESHOLDS_KEY

IPC_DECAYSCHEDULER_SERVICE_USERS_KEY

DECAYSCHEDULER_UNKNOWN_IDENTITY

IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_ENABLE_KEY

IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_ENABLE_DEFAULT

IPC_DECAYSCHEDULER_BACKOFF_RESPONSETIME_THRESHOLDS_KEY

DECAYSCHEDULER_METRICS_TOP_USER_COUNT

DECAYSCHEDULER_METRICS_TOP_USER_COUNT_DEFAULT

LOG

Constructor Detail

DecayRpcScheduler

Method Detail

getPriorityLevel

shouldBackOff

addResponseTime

getUniqueIdentityCount

getTotalCallVolume

getTotalRawCallVolume

getTotalServiceUserCallVolume

getTotalServiceUserRawCallVolume

getResponseTimeCountInLastWindow

getAverageResponseTime

getMetrics

getSchedulingDecisionSummary

getCallVolumeSummary

getDecayRpcSchedulerDetailedMetrics

stop