com.alibaba.csp.sentinel

Class SphU

java.lang.Object

com.alibaba.csp.sentinel.SphU

public class SphU
extends Object

Conceptually, physical or logical resource that need protection should be surrounded by an entry. The requests to this resource will be blocked if any criteria is met, eg. when any Rule's threshold is exceeded. Once blocked, a BlockException will be thrown.

To configure the criteria, we can use XXXRuleManager.loadRules() to add rules, eg. FlowRuleManager.loadRules(List), DegradeRuleManager.loadRules(List), SystemRuleManager.loadRules(List).

Following code is an example, "abc" represent a unique name for the protected resource:

  public void foo() {
     Entry entry = null;
     try {
        entry = SphU.entry("abc");
        // resource that need protection
     } catch (BlockException blockException) {
         // when goes there, it is blocked
         // add blocked handle logic here
     } catch (Throwable bizException) {
         // business exception
         Tracer.trace(bizException);
     } finally {
         // ensure finally be executed
         if (entry != null){
             entry.exit();
         }
     }
  }
 

Make sure SphU.entry() and Entry.exit() be paired in the same thread, otherwise ErrorEntryFreeException will be thrown.

Author:

jialiang.linjl

See Also:

SphO

Constructor Summary

Constructors

Constructor and Description
SphU()

Method Summary

Modifier and Type	Method and Description
static Entry	entry(Method method) Checking all Rules about the protected method.
static Entry	entry(Method method, EntryType type) Checking all Rules about the protected method.
static Entry	entry(Method method, EntryType type, int count) Checking all Rules about the protected method.
static Entry	entry(Method method, EntryType type, int count, Object... args) Checking all Rules about the protected method.
static Entry	entry(Method method, int count) Checking all Rules about the protected method.
static Entry	entry(String name) Checking all Rules about the resource.
static Entry	entry(String name, EntryType type) Checking all Rules about the resource.
static Entry	entry(String name, EntryType type, int count) Checking all Rules about the resource.
static Entry	entry(String name, EntryType type, int count, Object... args) Checking all Rules about the resource.
static Entry	entry(String name, int count) Checking all Rules about the resource.

Methods inherited from class java.lang.Object

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

Constructor Detail

SphU

public SphU()

Method Detail

entry

public static Entry entry(String name)
                   throws BlockException

Checking all Rules about the resource.

Parameters:

name - the unique name of the protected resource

Throws:

BlockException - if the block criteria is met, eg. when any rule's threshold is exceeded.

entry

public static Entry entry(Method method)
                   throws BlockException

Checking all Rules about the protected method.

Parameters:

method - the protected method

Throws:

BlockException - if the block criteria is met, eg. when any rule's threshold is exceeded.

entry

public static Entry entry(Method method,
                          int count)
                   throws BlockException

Checking all Rules about the protected method.

Parameters:

method - the protected method

count - tokens required

Throws:

BlockException - if the block criteria is met, eg. when any rule's threshold is exceeded.

entry

public static Entry entry(String name,
                          int count)
                   throws BlockException

Checking all Rules about the resource.

Parameters:

name - the unique string for the resource

count - tokens required

Throws:

BlockException - if the block criteria is met, eg. when any rule's threshold is exceeded.

entry

public static Entry entry(Method method,
                          EntryType type)
                   throws BlockException

Checking all Rules about the protected method.

Parameters:

method - the protected method

type - the resource is an inbound or an outbound method. This is used to mark whether it can be blocked when the system is unstable, only inbound traffic could be blocked by SystemRule

Throws:

BlockException - if the block criteria is met, eg. when any rule's threshold is exceeded.

entry

public static Entry entry(String name,
                          EntryType type)
                   throws BlockException

Checking all Rules about the resource.

Parameters:

name - the unique name for the protected resource

type - the resource is an inbound or an outbound method. This is used to mark whether it can be blocked when the system is unstable, only inbound traffic could be blocked by SystemRule

Throws:

BlockException - if the block criteria is met, eg. when any rule's threshold is exceeded.

entry

public static Entry entry(Method method,
                          EntryType type,
                          int count)
                   throws BlockException

Checking all Rules about the protected method.

Parameters:

method - the protected method

type - the resource is an inbound or an outbound method. This is used to mark whether it can be blocked when the system is unstable, only inbound traffic could be blocked by SystemRule

count - tokens required

Throws:

BlockException - if the block criteria is met, eg. when any rule's threshold is exceeded.

entry

public static Entry entry(String name,
                          EntryType type,
                          int count)
                   throws BlockException

Checking all Rules about the resource.

Parameters:

name - the unique name for the protected resource

type - the resource is an inbound or an outbound method. This is used to mark whether it can be blocked when the system is unstable, only inbound traffic could be blocked by SystemRule

count - tokens required

Throws:

BlockException - if the block criteria is met, eg. when any rule's threshold is exceeded.

entry

public static Entry entry(Method method,
                          EntryType type,
                          int count,
                          Object... args)
                   throws BlockException

Checking all Rules about the protected method.

Parameters:

method - the protected method

type - the resource is an inbound or an outbound method. This is used to mark whether it can be blocked when the system is unstable, only inbound traffic could be blocked by SystemRule

count - tokens required

args - the parameters of the method.

Throws:

BlockException - if the block criteria is met, eg. when any rule's threshold is exceeded.

entry

public static Entry entry(String name,
                          EntryType type,
                          int count,
                          Object... args)
                   throws BlockException

Checking all Rules about the resource.

Parameters:

name - the unique name for the protected resource

type - the resource is an inbound or an outbound method. This is used to mark whether it can be blocked when the system is unstable, only inbound traffic could be blocked by SystemRule

count - tokens required

args - extra parameters.

Throws:

BlockException - if the block criteria is met, eg. when any rule's threshold is exceeded.