MetricsSystem (Alluxio Parent 2.5.1-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 Map<String,MetricValue>`	`allMetrics()`
`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)` Get or add counter with the given name.
`static com.codahale.metrics.Counter`	`counterWithTags(String name, boolean shouldReport, String... tags)` Get or add counter with the given name with tags.
`static String`	`escape(AlluxioURI uri)` Escapes a URI, replacing "/" with "%2F".
`static String`	`getJobWorkerMetricName(String name)` Builds metric registry name for job worker instance.
`static String`	`getMasterMetricName(String name)` Builds metric registry names for master instance.
`static Map<String,Set<Metric>>`	`getMasterMetrics(Set<String> metricNames)` Gets all the master metrics belongs to the given metric names.
`static String`	`getMetricName(String name)` Converts a simple string to a qualified metric name based on the process type.
`static Metric`	`getMetricValue(String fullName)` Gets metric with the given full metric name.
`static int`	`getNumSinks()`
`static void`	`initShouldReportMetrics(MetricsSystem.InstanceType instanceType)` Initialize the `SHOULD_REPORT_METRICS`.
`static com.codahale.metrics.Meter`	`meter(String name)` Get or add meter with the given name.
`static com.codahale.metrics.Meter`	`meterWithTags(String name, boolean shouldReport, String... tags)` Get or add meter with the given 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`	`resetAllMetrics()` Resets all the metrics in the MetricsSystem.
`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)` Get or add timer with the given 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
  - getMasterMetricName
```
public static String getMasterMetricName(String name)
```
    Builds metric registry names for master instance. The pattern is instance.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)
```
    Get or add counter with the given name. The counter stores in the metrics system is never removed but may reset to zero.
    
    Parameters:
    
    name - the name of the metric
    
    Returns:
    
    a counter object with the qualified metric name
  - counterWithTags
```
public static com.codahale.metrics.Counter counterWithTags(String name,
                                                           boolean shouldReport,
                                                           String... tags)
```
    Get or add counter with the given name with tags. The counter stores in the metrics system is never removed but may reset to zero. If this metric can be aggregated at cluster level and should report to leading master, add it to the should report metrics map. This method is added to add worker metrics with ufs tags into the should report metrics map.
    
    Parameters:
    
    name - the metric name
    
    shouldReport - whether this metric should be reported
    
    tags - the tag name and tag value pairs
    
    Returns:
    
    a counter object with the qualified metric name
  - meter
```
public static com.codahale.metrics.Meter meter(String name)
```
    Get or add meter with the given name. The returned meter may be changed due to resetAllMetrics()
    
    Parameters:
    
    name - the name of the metric
    
    Returns:
    
    a meter object with the qualified metric name
  - meterWithTags
```
public static com.codahale.metrics.Meter meterWithTags(String name,
                                                       boolean shouldReport,
                                                       String... tags)
```
    Get or add meter with the given name. The returned meter may be changed due to resetAllMetrics() If this metric can be aggregated at cluster level and should report to leading master, add it to the should report metrics map. This method is added to add worker metrics with ufs tags into the should report metrics map.
    
    Parameters:
    
    name - the name of the metric
    
    shouldReport - whether this metric should be reported
    
    tags - the tag name and tag value pairs
    
    Returns:
    
    a meter object with the qualified metric name
  - timer
```
public static com.codahale.metrics.Timer timer(String name)
```
    Get or add timer with the given name. The returned timer may be changed due to resetAllMetrics()
    
    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
  - 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
  - getMasterMetrics
```
public static Map<String,Set<Metric>> getMasterMetrics(Set<String> metricNames)
```
    Gets all the master metrics belongs to the given metric names.
    
    Parameters:
    
    metricNames - the name of the metrics to get
    
    Returns:
    
    a metric map from metric name to metrics with this name
  - getMetricValue
```
@Nullable
public static Metric getMetricValue(String fullName)
```
    Gets metric with the given full metric name.
    
    Parameters:
    
    fullName - the full name of the metric to get
    
    Returns:
    
    a metric set with the master metric of the given metric name
  - allMetrics
```
public static Map<String,MetricValue> allMetrics()
```
    Returns:
    
    a map of all metrics stored in the current node from metric name to MetricValue
  - initShouldReportMetrics
```
public static void initShouldReportMetrics(MetricsSystem.InstanceType instanceType)
```
    Initialize the SHOULD_REPORT_METRICS. This should be called only once. Note that this method is able to catch most of the should report metrics except worker metrics with ufs tags.
    
    Parameters:
    
    instanceType - the instance type
  - resetAllMetrics
```
public static void resetAllMetrics()
```
    Resets all the metrics in the MetricsSystem. This method is not thread-safe and should be used sparingly.
  - clearAllMetrics
```
public static void clearAllMetrics()
```
    Resets the metric registry and removes all the metrics.
  - resetCountersAndGauges
```
public static void resetCountersAndGauges()
```
    Resets all counters to 0 and unregisters gauges for testing.

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

getMasterMetricName

getJobWorkerMetricName

checkMinimalPollingPeriod

stripInstanceAndHost

escape

unescape

counter

counterWithTags

meter

meterWithTags

timer

registerGaugeIfAbsent

reportWorkerMetrics

reportClientMetrics

getMasterMetrics

getMetricValue

allMetrics

initShouldReportMetrics

resetAllMetrics

clearAllMetrics

resetCountersAndGauges