com.alibaba.csp.sentinel.node

Class StatisticNode

java.lang.Object

com.alibaba.csp.sentinel.node.StatisticNode

All Implemented Interfaces:

Node, OccupySupport, DebugSupport

Direct Known Subclasses:

ClusterNode, DefaultNode

public class StatisticNode
extends Object
implements Node

The statistic node keep three kinds of real-time statistics metrics:

1. metrics in second level (rollingCounterInSecond)
2. metrics in minute level (rollingCounterInMinute)
3. thread count

Sentinel use sliding window to record and count the resource statistics in real-time. The sliding window infrastructure behind the ArrayMetric is LeapArray.

case 1: When the first request comes in, Sentinel will create a new window bucket of a specified time-span to store running statics, such as total response time(rt), incoming request(QPS), block request(bq), etc. And the time-span is defined by sample count.

        0      100ms
  +-------+--→ Sliding Windows
            ^
            |
          request
 

Sentinel use the statics of the valid buckets to decide whether this request can be passed. For example, if a rule defines that only 100 requests can be passed, it will sum all qps in valid buckets, and compare it to the threshold defined in rule.

case 2: continuous requests

  0    100ms    200ms    300ms
  +-------+-------+-------+-----→ Sliding Windows
                      ^
                      |
                   request
 

case 3: requests keeps coming, and previous buckets become invalid

  0    100ms    200ms     800ms    900ms  1000ms    1300ms
  +-------+-------+ ...... +-------+-------+ ...... +-------+-----→ Sliding Windows
                                                      ^
                                                      |
                                                    request
 

The sliding window should become:

 300ms     800ms  900ms  1000ms  1300ms
  + ...... +-------+ ...... +-------+-----→ Sliding Windows
                                                      ^
                                                      |
                                                    request
 

Author:

qinan.qn, jialiang.linjl

Constructor Summary

Constructors

Constructor and Description
StatisticNode()

Method Summary

Modifier and Type	Method and Description
void	addOccupiedPass(int acquireCount) Add occupied pass request, which represents pass requests that borrow the latter windows' token.
void	addPassRequest(int count) Add pass count.
void	addRtAndSuccess(long rt, int successCount) Add rt and success count.
void	addWaitingRequest(long futureTime, int acquireCount) Add request that occupied.
double	avgRt() Get average rt per second.
double	blockQps() Get block request per second.
long	blockRequest() Get blocked request count per minute (totalBlockRequest).
int	curThreadNum() Get current active thread count.
void	debug() For debug;
void	decreaseThreadNum() Decrease current thread count.
double	exceptionQps() Get exception count per second.
void	increaseBlockQps(int count) Increase the block count.
void	increaseExceptionQps(int count) Add the biz exception count.
void	increaseThreadNum() Increase current thread count.
double	maxSuccessQps() Get estimated max success QPS till now.
Map<Long,MetricNode>	metrics() Fetch all valid metric nodes of resources.
double	minRt() Get minimal response time.
double	occupiedPassQps() Get current occupied pass QPS.
double	passQps() Get pass request per second.
double	previousBlockQps() Get last second block QPS.
double	previousPassQps() Last window QPS.
List<MetricNode>	rawMetricsInMin(Predicate<Long> timePredicate) Fetch all raw metric items that satisfies the time predicate.
void	reset() Reset the internal counter.
double	successQps() Get Entry.exit() request per second.
long	totalException() Get exception count per minute.
long	totalPass() Get pass count per minute.
double	totalQps() Get Node.passQps() + Node.blockQps() request per second.
long	totalRequest() Get incoming request per minute (pass + block).
long	totalSuccess() Get Entry.exit() count per minute.
long	tryOccupyNext(long currentTime, int acquireCount, double threshold) Try to occupy latter time windows' tokens.
long	waiting() Get current waiting amount.

Methods inherited from class java.lang.Object

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

Constructor Detail

StatisticNode

public StatisticNode()

Method Detail

metrics

public Map<Long,MetricNode> metrics()

Description copied from interface: Node

Fetch all valid metric nodes of resources.

Specified by:

metrics in interface Node

Returns:

valid metric nodes of resources

rawMetricsInMin

public List<MetricNode> rawMetricsInMin(Predicate<Long> timePredicate)

Description copied from interface: Node

Fetch all raw metric items that satisfies the time predicate.

Specified by:

rawMetricsInMin in interface Node

Parameters:

timePredicate - time predicate

Returns:

raw metric items that satisfies the time predicate

reset

public void reset()

Description copied from interface: Node

Reset the internal counter. Reset is needed when IntervalProperty.INTERVAL or SampleCountProperty.SAMPLE_COUNT is changed.

Specified by:

reset in interface Node

totalRequest

public long totalRequest()

Description copied from interface: Node

Get incoming request per minute (pass + block).

Specified by:

totalRequest in interface Node

Returns:

total request count per minute

blockRequest

public long blockRequest()

Description copied from interface: Node

Get blocked request count per minute (totalBlockRequest).

Specified by:

blockRequest in interface Node

Returns:

total blocked request count per minute

blockQps

public double blockQps()

Description copied from interface: Node

Get block request per second.

Specified by:

blockQps in interface Node

Returns:

QPS of blocked requests

previousBlockQps

public double previousBlockQps()

Description copied from interface: Node

Get last second block QPS.

Specified by:

previousBlockQps in interface Node

previousPassQps

public double previousPassQps()

Description copied from interface: Node

Last window QPS.

Specified by:

previousPassQps in interface Node

totalQps

public double totalQps()

Description copied from interface: Node

Get Node.passQps() + Node.blockQps() request per second.

Specified by:

totalQps in interface Node

Returns:

QPS of passed and blocked requests

totalSuccess

public long totalSuccess()

Description copied from interface: Node

Get Entry.exit() count per minute.

Specified by:

totalSuccess in interface Node

Returns:

total completed request count per minute

exceptionQps

public double exceptionQps()

Description copied from interface: Node

Get exception count per second.

Specified by:

exceptionQps in interface Node

Returns:

QPS of exception occurs

totalException

public long totalException()

Description copied from interface: Node

Get exception count per minute.

Specified by:

totalException in interface Node

Returns:

total business exception count per minute

passQps

public double passQps()

Description copied from interface: Node

Get pass request per second.

Specified by:

passQps in interface Node

Returns:

QPS of passed requests

totalPass

public long totalPass()

Description copied from interface: Node

Get pass count per minute.

Specified by:

totalPass in interface Node

Returns:

total passed request count per minute

successQps

public double successQps()

Description copied from interface: Node

Get Entry.exit() request per second.

Specified by:

successQps in interface Node

Returns:

QPS of completed requests

maxSuccessQps

public double maxSuccessQps()

Description copied from interface: Node

Get estimated max success QPS till now.

Specified by:

maxSuccessQps in interface Node

Returns:

max completed QPS

occupiedPassQps

public double occupiedPassQps()

Description copied from interface: OccupySupport

Get current occupied pass QPS.

Specified by:

occupiedPassQps in interface OccupySupport

Returns:

current occupied pass QPS

avgRt

public double avgRt()

Description copied from interface: Node

Get average rt per second.

Specified by:

avgRt in interface Node

Returns:

average response time per second

minRt

public double minRt()

Description copied from interface: Node

Get minimal response time.

Specified by:

minRt in interface Node

Returns:

recorded minimal response time

curThreadNum

public int curThreadNum()

Description copied from interface: Node

Get current active thread count.

Specified by:

curThreadNum in interface Node

Returns:

current active thread count

addPassRequest

public void addPassRequest(int count)

Description copied from interface: Node

Add pass count.

Specified by:

addPassRequest in interface Node

Parameters:

count - count to add pass

addRtAndSuccess

public void addRtAndSuccess(long rt,
                            int successCount)

Description copied from interface: Node

Add rt and success count.

Specified by:

addRtAndSuccess in interface Node

Parameters:

rt - response time

successCount - success count to add

increaseBlockQps

public void increaseBlockQps(int count)

Description copied from interface: Node

Increase the block count.

Specified by:

increaseBlockQps in interface Node

Parameters:

count - count to add

increaseExceptionQps

public void increaseExceptionQps(int count)

Description copied from interface: Node

Add the biz exception count.

Specified by:

increaseExceptionQps in interface Node

Parameters:

count - count to add

increaseThreadNum

public void increaseThreadNum()

Description copied from interface: Node

Increase current thread count.

Specified by:

increaseThreadNum in interface Node

decreaseThreadNum

public void decreaseThreadNum()

Description copied from interface: Node

Decrease current thread count.

Specified by:

decreaseThreadNum in interface Node

debug

public void debug()

Description copied from interface: DebugSupport

For debug;

Specified by:

debug in interface DebugSupport

tryOccupyNext

public long tryOccupyNext(long currentTime,
                          int acquireCount,
                          double threshold)

Description copied from interface: OccupySupport

Try to occupy latter time windows' tokens. If occupy success, a value less than occupyTimeout in OccupyTimeoutProperty will be return.

Each time we occupy tokens of the future window, current thread should sleep for the corresponding time for smoothing QPS. We can't occupy tokens of the future with unlimited, the sleep time limit is occupyTimeout in OccupyTimeoutProperty.

Specified by:

tryOccupyNext in interface OccupySupport

Parameters:

currentTime - current time millis.

acquireCount - tokens count to acquire.

threshold - qps threshold.

Returns:

time should sleep. Time >= occupyTimeout in OccupyTimeoutProperty means occupy fail, in this case, the request should be rejected immediately.

waiting

public long waiting()

Description copied from interface: OccupySupport

Get current waiting amount. Useful for debug.

Specified by:

waiting in interface OccupySupport

Returns:

current waiting amount

addWaitingRequest

public void addWaitingRequest(long futureTime,
                              int acquireCount)

Description copied from interface: OccupySupport

Add request that occupied.

Specified by:

addWaitingRequest in interface OccupySupport

Parameters:

futureTime - future timestamp that the acquireCount should be added on.

acquireCount - tokens count.

addOccupiedPass

public void addOccupiedPass(int acquireCount)

Description copied from interface: OccupySupport

Add occupied pass request, which represents pass requests that borrow the latter windows' token.

Specified by:

addOccupiedPass in interface OccupySupport

Parameters:

acquireCount - tokens count.