MetricsSystem (Alluxio Parent 2.1.3-SNAPSHOT API)

java.lang.Object
- alluxio.metrics.MetricsSystem

```
@ThreadSafe
public final class MetricsSystem
extends Object
```
A MetricsSystem is created by a specific instance(master, worker). It polls the metrics sources periodically and pass the data to the sinks. The syntax of the metrics configuration file is: sink.[name].[options]=[value]

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class MetricsSystem.InstanceType
An enum of supported instance type.

Nested Classes
Modifier and Type	Class and Description
`static class`	`MetricsSystem.InstanceType` An enum of supported instance type.

Field Summary

Fields
Modifier and Type Field and Description

static String CLUSTER

static com.codahale.metrics.MetricRegistry METRIC_REGISTRY

static String SINK_REGEX

Fields
Modifier and Type	Field and Description
`static String`	`CLUSTER`
`static com.codahale.metrics.MetricRegistry`	`METRIC_REGISTRY`
`static String`	`SINK_REGEX`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static List<Metric>`	`allClientMetrics()`
`static List<Metric>`	`allMasterMetrics()`
`static List<Metric>`	`allWorkerMetrics()`
`static void`	`checkMinimalPollingPeriod(TimeUnit pollUnit, int pollPeriod)` Checks if the poll period is smaller that the minimal poll period which is 1 second.
`static void`	`clearAllMetrics()` Resets the metric registry and removes all the metrics.
`static com.codahale.metrics.Counter`	`counter(String name)`
`static String`	`escape(AlluxioURI uri)` Escapes a URI, replacing "/" with "%2F".
`static String`	`getClusterMetricName(String name)` Builds metric registry names for cluster.
`static String`	`getJobWorkerMetricName(String name)` Builds metric registry name for job worker instance.
`static String`	`getMetricName(String name)` Converts a simple string to a qualified metric name based on the process type.
`static int`	`getNumSinks()`
`static com.codahale.metrics.Meter`	`meter(String name)`
`static <T> void`	`registerGaugeIfAbsent(String name, com.codahale.metrics.Gauge<T> metric)` Registers a gauge if it has not been registered.
`static List<Metric>`	`reportClientMetrics()`
`static List<Metric>`	`reportWorkerMetrics()`
`static void`	`resetCountersAndGauges()` Resets all counters to 0 and unregisters gauges for testing.
`static void`	`startSinks(String metricsConfFile)` Starts sinks specified in the configuration.
`static void`	`startSinksFromConfig(MetricsConfig config)` Starts sinks from a given metrics configuration.
`static void`	`stopSinks()` Stops all the sinks.
`static String`	`stripInstanceAndHost(String metricsName)` Removes the instance and host from the given metric name, returning the result.
`static com.codahale.metrics.Timer`	`timer(String name)`
`static String`	`unescape(String uri)` Unescapes a URI, reverts it to before the escape, to display it correctly.

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

- Field Detail
  - CLUSTER
```
public static final String CLUSTER
```
    See Also:
    
    Constant Field Values
  - METRIC_REGISTRY
```
public static final com.codahale.metrics.MetricRegistry METRIC_REGISTRY
```
  - SINK_REGEX
```
public static final String SINK_REGEX
```
    See Also:
    
    Constant Field Values
- Method Detail
  - startSinks
```
public static void startSinks(String metricsConfFile)
```
    Starts sinks specified in the configuration. This is an no-op if the sinks have already been started. Note: This has to be called after Alluxio configuration is initialized.
    
    Parameters:
    
    metricsConfFile - the location of the metrics configuration file
  - startSinksFromConfig
```
public static void startSinksFromConfig(MetricsConfig config)
```
    Starts sinks from a given metrics configuration. This is made public for unit test.
    
    Parameters:
    
    config - the metrics config
  - stopSinks
```
public static void stopSinks()
```
    Stops all the sinks.
  - getNumSinks
```
public static int getNumSinks()
```
    Returns:
    
    the number of sinks started
  - getMetricName
```
public static String getMetricName(String name)
```
    Converts a simple string to a qualified metric name based on the process type.
    
    Parameters:
    
    name - the name of the metric
    
    Returns:
    
    the metric with instance and id tags
  - getClusterMetricName
```
public static String getClusterMetricName(String name)
```
    Builds metric registry names for cluster. The pattern is cluster.metricName.
    
    Parameters:
    
    name - the metric name
    
    Returns:
    
    the metric registry name
  - getJobWorkerMetricName
```
public static String getJobWorkerMetricName(String name)
```
    Builds metric registry name for job worker instance. The pattern is instance.uniqueId.metricName.
    
    Parameters:
    
    name - the metric name
    
    Returns:
    
    the metric registry name
  - checkMinimalPollingPeriod
```
public static void checkMinimalPollingPeriod(TimeUnit pollUnit,
                                             int pollPeriod)
                                      throws IllegalArgumentException
```
    Checks if the poll period is smaller that the minimal poll period which is 1 second.
    
    Parameters:
    
    pollUnit - the polling unit
    
    pollPeriod - the polling period
    
    Throws:
    
    IllegalArgumentException - if the polling period is invalid
  - stripInstanceAndHost
```
public static String stripInstanceAndHost(String metricsName)
```
    Removes the instance and host from the given metric name, returning the result.
    
    Parameters:
    
    metricsName - the long metrics name with instance and host name
    
    Returns:
    
    the metrics name without instance and host name
  - escape
```
public static String escape(AlluxioURI uri)
```
    Escapes a URI, replacing "/" with "%2F". Replaces "." with "%2E" because dots are used as tag separators in metric names. Replaces "%" with "%25" because it now has special use. So when the URI is used in a metric name, the "." and "/" won't be interpreted as path separators unescaped and interfere with the internal logic of AlluxioURI.
    
    Parameters:
    
    uri - the URI to escape
    
    Returns:
    
    the string representing the escaped URI
  - unescape
```
public static String unescape(String uri)
```
    Unescapes a URI, reverts it to before the escape, to display it correctly.
    
    Parameters:
    
    uri - the escaped URI to unescape
    
    Returns:
    
    the string representing the unescaped original URI
  - counter
```
public static com.codahale.metrics.Counter counter(String name)
```
    Parameters:
    
    name - the name of the metric
    
    Returns:
    
    a counter object with the qualified metric name
  - meter
```
public static com.codahale.metrics.Meter meter(String name)
```
    Parameters:
    
    name - the name of the metric
    
    Returns:
    
    a meter object with the qualified metric name
  - timer
```
public static com.codahale.metrics.Timer timer(String name)
```
    Parameters:
    
    name - the name of the metric
    
    Returns:
    
    a timer object with the qualified metric name
  - registerGaugeIfAbsent
```
public static <T> void registerGaugeIfAbsent(String name,
                                             com.codahale.metrics.Gauge<T> metric)
```
    Registers a gauge if it has not been registered.
    
    Type Parameters:
    
    T - the type
    
    Parameters:
    
    name - the gauge name
    
    metric - the gauge
  - resetCountersAndGauges
```
public static void resetCountersAndGauges()
```
    Resets all counters to 0 and unregisters gauges for testing.
  - reportWorkerMetrics
```
public static List<Metric> reportWorkerMetrics()
```
    Returns:
    
    the worker metrics to send via RPC
  - reportClientMetrics
```
public static List<Metric> reportClientMetrics()
```
    Returns:
    
    the client metrics to send via RPC
  - allMasterMetrics
```
public static List<Metric> allMasterMetrics()
```
    Returns:
    
    all the master's metrics in the format of Metric
  - allWorkerMetrics
```
public static List<Metric> allWorkerMetrics()
```
    Returns:
    
    all the worker's metrics in the format of Metric
  - allClientMetrics
```
public static List<Metric> allClientMetrics()
```
    Returns:
    
    all the client's metrics in the format of Metric
  - clearAllMetrics
```
public static void clearAllMetrics()
```
    Resets the metric registry and removes all the metrics.

Class MetricsSystem

Nested Class Summary

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

CLUSTER

METRIC_REGISTRY

SINK_REGEX

Method Detail

startSinks

startSinksFromConfig

stopSinks

getNumSinks

getMetricName

getClusterMetricName

getJobWorkerMetricName

checkMinimalPollingPeriod

stripInstanceAndHost

escape

unescape

counter

meter

timer

registerGaugeIfAbsent

resetCountersAndGauges

reportWorkerMetrics

reportClientMetrics

allMasterMetrics

allWorkerMetrics

allClientMetrics

clearAllMetrics