QoSHandler (gateleen-qos 1.0.4 API)

java.lang.Object
- org.swisspush.gateleen.qos.QoSHandler

```
public class QoSHandler
extends java.lang.Object
```
QoS Handler.
```
     {
        "config":{
            "percentile":75,
            "quorum":40,
            "period":5, 
            "minSampleCount" : 1000,
            "minSentinelCount" : 5
        },
        "sentinels":{
            "sentinelA":{
                "percentile":50
            },
            "sentinelB":{},
            "sentinelC":{},
            "sentinelD":{}
        },
        "rules":{
            "/test/myapi1/v1/.*":{
                "reject":1.2,
                "warn":0.5
            },
            "/test/myapi2/v1/.*":{
                "reject":0.3
            }
        }
    }
 
```
The config section defines the global settings of the QoS.
percentile: Indicates which percentile value from the metrics will be used (eg. 50, 75, 95, 98, 999 or 99)
quorum: Percentage of the the sentinels which have to be over the calculated threshold to trigger the given rule.
period: The period (in seconds) after which a new calculation is triggered. If a rule is set to reject requests, it will reject requests until the next period.
minSampleCount: The min. count of the samples a sentinel has to provide to be regarded for the QoS calculation.
minSentinelCount:The min count of sentinels which have to be available to perform a QoS calculation. A sentinel is only available if it corresponds to the minSampleCount rule.

The sentinels section defines which metrics (defined in the routing rules) will be used as sentinels. To determine the load, the lowest measured percentile value will be preserved for each sentinel and put in relation to the current percentile value. This calculated ratio is later used to check if a rule needs some actions or not. You can override the taken percentile value for a specific sentinel by setting the attribute percentile.

The rules section defines the rules for the QoS. Each rule is based on a pattern like the routing rules.
The possible attributes are:
reject: The ratio (eg. 1.3 means that *quorum* % of all sentinels must have an even or greater current ratio) which defines when a rule rejects the given request.
warn: The ratio which defines when a rule writes a warning in the log without rejecting the given request.

You can combine warn and reject

Field Summary

Fields
Modifier and Type Field and Description

protected static java.lang.String REJECT_ACTION

protected static java.lang.String WARN_ACTION

Fields
Modifier and Type	Field and Description
`protected static java.lang.String`	`REJECT_ACTION`
`protected static java.lang.String`	`WARN_ACTION`

Constructor Summary

Constructors
Constructor and Description
`QoSHandler(io.vertx.core.Vertx vertx, org.swisspush.gateleen.core.storage.ResourceStorage storage, java.lang.String qosSettingsPath, java.util.Map<java.lang.String,java.lang.Object> properties, java.lang.String prefix)` Creates a new instance of the QoSHandler.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected boolean`	`actionNecessary(java.lang.Double ratio, double thresholdSentinelRatio)` Takes the ratio of the rule and compares if the calculated sentinel ratio from the desc.
`protected void`	`cancelTimer()` Cancels the timer.
`protected QoSConfig`	`createQoSConfig(io.vertx.core.json.JsonObject qosSettings)` Creates the QoS config object from the given JsonObject and returns it.
`protected java.util.List<QoSSentinel>`	`createQoSSentinels(io.vertx.core.json.JsonObject qosSettings)` Creates the QoS sentinel objects from the given JsonObject and returns them in a list.
`protected void`	`evaluateQoSActions()` Calculates the threshold and determines if any action for each rule has to be applied.
`QoSSentinel`	`getOldSentinel(java.lang.String sentinelName)` We try to retrive the old sentinel (if available).
`protected java.util.List<QoSRule>`	`getQosRules()` Returns a list of the QoS rules.
`protected java.util.List<QoSSentinel>`	`getQosSentinels()` Gets a list of all sentinels.
`boolean`	`handle(io.vertx.core.http.HttpServerRequest request)` Processes the request if it’s a request concerning the updates of the QoS settings or if it’s a request affected by the QoS rules.
`protected io.vertx.core.json.JsonObject`	`parseQoSSettings(io.vertx.core.buffer.Buffer buffer)` Tries to parse the QoS settings.
`protected void`	`setGlobalQoSConfig(QoSConfig globalQoSConfig)` Sets the global configuration for the QoS.
`protected void`	`setMBeanServer(javax.management.MBeanServer mbeanServer)` Sets the mbean server.
`protected void`	`setQosRules(java.util.List<QoSRule> qosRules)` Sets the QoS rules.
`protected void`	`setQosSentinels(java.util.List<QoSSentinel> qosSentinels)` Sets a list of all sentinels.

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

- Field Detail
  - REJECT_ACTION
```
protected static final java.lang.String REJECT_ACTION
```
    See Also:
    
    Constant Field Values
  - WARN_ACTION
```
protected static final java.lang.String WARN_ACTION
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - QoSHandler
```
public QoSHandler(io.vertx.core.Vertx vertx,
                  org.swisspush.gateleen.core.storage.ResourceStorage storage,
                  java.lang.String qosSettingsPath,
                  java.util.Map<java.lang.String,java.lang.Object> properties,
                  java.lang.String prefix)
```
    Creates a new instance of the QoSHandler.
    
    Parameters:
    
    vertx - vertx reference
    
    storage - storage reference
    
    qosSettingsPath - the url path to the QoS rules
    
    properties - the properties
    
    prefix - the prefix for the server
- Method Detail
  - setMBeanServer
```
protected void setMBeanServer(javax.management.MBeanServer mbeanServer)
```
    Sets the mbean server. This method is usefull for mocking in tests.
    
    Parameters:
    
    mbeanServer - a mbean server
  - handle
```
public boolean handle(io.vertx.core.http.HttpServerRequest request)
```
    Processes the request if it’s a request concerning the updates of the QoS settings or if it’s a request affected by the QoS rules. In either case the return value will be true otherwise false.
    
    Parameters:
    
    request -
    
    Returns:
    
    true if request is QoS update or affected by the rules, otherwise false.
  - createQoSConfig
```
protected QoSConfig createQoSConfig(io.vertx.core.json.JsonObject qosSettings)
```
    Creates the QoS config object from the given JsonObject and returns it.
    
    Parameters:
    
    qosSettings - json object
    
    Returns:
    
    the global QoS config object, null if the config section is not present.
  - createQoSSentinels
```
protected java.util.List<QoSSentinel> createQoSSentinels(io.vertx.core.json.JsonObject qosSettings)
```
    Creates the QoS sentinel objects from the given JsonObject and returns them in a list.
    
    Parameters:
    
    qosSettings - json object
    
    Returns:
    
    a list with the QoSSentinel objects, empty if the sentinel section is not present or empty.
  - getOldSentinel
```
public QoSSentinel getOldSentinel(java.lang.String sentinelName)
```
    We try to retrive the old sentinel (if available).
    
    Parameters:
    
    sentinelName - the name of the sentinel.
    
    Returns:
    
    old sentinel object or null if no sentinel was found
  - parseQoSSettings
```
protected io.vertx.core.json.JsonObject parseQoSSettings(io.vertx.core.buffer.Buffer buffer)
```
    Tries to parse the QoS settings.
    
    Parameters:
    
    buffer - buffer from the request
    
    Returns:
    
    a JsonObject containing the settings.
  - cancelTimer
```
protected void cancelTimer()
```
    Cancels the timer.
    This method is protected to be used in tests where you wish to manually trigger the evaluation.
  - evaluateQoSActions
```
protected void evaluateQoSActions()
```
    Calculates the threshold and determines if any action for each rule has to be applied.
  - actionNecessary
```
protected boolean actionNecessary(java.lang.Double ratio,
                                  double thresholdSentinelRatio)
```
    Takes the ratio of the rule and compares if the calculated sentinel ratio from the desc. sorted list at the index coresponding to the percentual value (quorum) of all sentinel api's is lower or even.
    
    Parameters:
    
    ratio -
    
    thresholdSentinelRatio -
    
    Returns:
    
    true if any action must be applied, otherwise false
  - setGlobalQoSConfig
```
protected void setGlobalQoSConfig(QoSConfig globalQoSConfig)
```
    Sets the global configuration for the QoS.
    
    Parameters:
    
    globalQoSConfig - the config object for QoS.
  - getQosRules
```
protected java.util.List<QoSRule> getQosRules()
```
    Returns a list of the QoS rules.
    
    Returns:
    
    list of QoS rules.
  - setQosRules
```
protected void setQosRules(java.util.List<QoSRule> qosRules)
```
    Sets the QoS rules.
    
    Parameters:
    
    qosRules - a list of the QoS rule objects
  - setQosSentinels
```
protected void setQosSentinels(java.util.List<QoSSentinel> qosSentinels)
```
    Sets a list of all sentinels.
    
    Parameters:
    
    qosSentinels - list with sentinel objects
  - getQosSentinels
```
protected java.util.List<QoSSentinel> getQosSentinels()
```
    Gets a list of all sentinels.
    
    Returns:
    
    list with sentinel objects

Class QoSHandler

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

REJECT_ACTION

WARN_ACTION

Constructor Detail

QoSHandler

Method Detail

setMBeanServer

handle

createQoSConfig

createQoSSentinels

getOldSentinel

parseQoSSettings

cancelTimer

evaluateQoSActions

actionNecessary

setGlobalQoSConfig

getQosRules

setQosRules

setQosSentinels

getQosSentinels