com.alibaba.csp.sentinel.slots.system

Class SystemRule

java.lang.Object

com.alibaba.csp.sentinel.slots.block.AbstractRule

com.alibaba.csp.sentinel.slots.system.SystemRule

All Implemented Interfaces:

Rule

public class SystemRule
extends AbstractRule

Sentinel System Rule makes the inbound traffic and capacity meet. It takes average RT, QPS and thread count of requests into account. And it also provides a measurement of system's load, but only available on Linux.

We recommend to coordinate highestSystemLoad, qps, avgRt and maxThread to make sure your system run in safety level.

To set the threshold appropriately, performance test may be needed.

Author:

jialiang.linjl, Carpenter Lee

See Also:

SystemRuleManager

Constructor Summary

Constructors

Constructor and Description
SystemRule()

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object o)
long	getAvgRt()
double	getHighestCpuUsage() Get highest cpu usage.
double	getHighestSystemLoad()
long	getMaxThread()
double	getQps()
int	hashCode()
boolean	passCheck(Context context, DefaultNode node, int count, Object... args) Check whether current statistical indicators meet this rule, which means not exceeding any threshold.
void	setAvgRt(long avgRt) Set max average RT(response time) of all passed requests.
void	setHighestCpuUsage(double highestCpuUsage) set highest cpu usage.
void	setHighestSystemLoad(double highestSystemLoad) Set highest load.
void	setMaxThread(long maxThread) Set max PARALLEL working thread.
void	setQps(double qps) Set max total QPS.
String	toString()

Methods inherited from class com.alibaba.csp.sentinel.slots.block.AbstractRule

as, getLimitApp, getResource, setLimitApp, setResource

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

SystemRule

public SystemRule()

Method Detail

getQps

public double getQps()

setQps

public void setQps(double qps)

Set max total QPS. In a high concurrency condition, real passed QPS may be greater than max QPS set. The real passed QPS will nearly satisfy the following formula:

real passed QPS = QPS set + concurrent thread number

Parameters:

qps - max total QOS, values <= 0 are special for clearing the threshold.

getMaxThread

public long getMaxThread()

setMaxThread

public void setMaxThread(long maxThread)

Set max PARALLEL working thread. When concurrent thread number is greater than maxThread only maxThread will run in parallel.

Parameters:

maxThread - max parallel thread number, values <= 0 are special for clearing the threshold.

getAvgRt

public long getAvgRt()

setAvgRt

public void setAvgRt(long avgRt)

Set max average RT(response time) of all passed requests.

Parameters:

avgRt - max average response time, values <= 0 are special for clearing the threshold.

getHighestSystemLoad

public double getHighestSystemLoad()

setHighestSystemLoad

public void setHighestSystemLoad(double highestSystemLoad)

Set highest load. The load is not same as Linux system load, which is not sensitive enough. To calculate the load, both Linux system load, current global response time and global QPS will be considered, which means that we need to coordinate with setAvgRt(long) and setQps(double)

Note that this parameter is only available on Unix like system.

Parameters:

highestSystemLoad - highest system load, values <= 0 are special for clearing the threshold.

See Also:

SystemRuleManager

getHighestCpuUsage

public double getHighestCpuUsage()

Get highest cpu usage. Cpu usage is between [0, 1]

Returns:

highest cpu usage

setHighestCpuUsage

public void setHighestCpuUsage(double highestCpuUsage)

set highest cpu usage. Cpu usage is between [0, 1]

Parameters:

highestCpuUsage - the value to set.

passCheck

public boolean passCheck(Context context,
                         DefaultNode node,
                         int count,
                         Object... args)

Description copied from interface: Rule

Check whether current statistical indicators meet this rule, which means not exceeding any threshold.

Parameters:

context - current Context

node - current Node

count - tokens needed.

args - arguments of the original invocation.

Returns:

If current statistical indicators not exceeding any threshold return true, otherwise return false.

equals

public boolean equals(Object o)

Overrides:

equals in class AbstractRule

hashCode

public int hashCode()

Overrides:

hashCode in class AbstractRule

toString

public String toString()

Overrides:

toString in class Object