Configuration (Alluxio Parent 305-SNAPSHOT API)

java.lang.Object
- alluxio.conf.Configuration

```
public final class Configuration
extends Object
```
Global configuration properties of Alluxio. This class works like a dictionary and serves each Alluxio configuration property as a key-value pair.
Alluxio configuration properties are loaded into this class in the following order with decreasing priority:
1. Java system properties;
2. Environment variables via alluxio-env.sh or from OS settings;
3. Site specific properties via alluxio-site.properties file;
The default properties are defined in the PropertyKey class in the codebase. Alluxio users can override values of these default properties by creating alluxio-site.properties and putting it under java CLASSPATH when running Alluxio (e.g., ${ALLUXIO_HOME}/conf/)
This class defines many convenient static methods which delegate to an internal InstancedConfiguration. To use this global configuration in a method that takes AlluxioConfiguration as an argument, pass global().

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static boolean`	`compareAndSetServerConfigReference(InstancedConfiguration conf, InstancedConfiguration newConf)` Compares and swap the two conf.
`static InstancedConfiguration`	`copyGlobal()`
`static AlluxioProperties`	`copyProperties()` Create and return a copy of all properties.
`static Object`	`get(PropertyKey key)` Gets the value for the given key in the `Properties`; if this key is not found, a RuntimeException is thrown.
`static Object`	`get(PropertyKey key, ConfigurationValueOptions options)` Gets the value for the given key in the `Properties`; if this key is not found, a RuntimeException is thrown.
`static boolean`	`getBoolean(PropertyKey key)` Gets the boolean representation of the value for the given key.
`static long`	`getBytes(PropertyKey key)` Gets the bytes of the value for the given key.
`static <T> Class<T>`	`getClass(PropertyKey key)` Gets the value for the given key as a class.
`static InstancedConfiguration`	`getClusterConf(GetConfigurationPResponse response, AlluxioConfiguration conf, Scope scope)` Loads the cluster level configuration from the get configuration response, filters out the configuration for certain scope, and merges it with the existing configuration.
`static List<ConfigProperty>`	`getConfiguration(Scope scope)` Gets all configuration properties filtered by the specified scope.
`static double`	`getDouble(PropertyKey key)` Gets the double representation of the value for the given key.
`static java.time.Duration`	`getDuration(PropertyKey key)` Gets the time of the key as a duration.
`static <T extends Enum<T>> T`	`getEnum(PropertyKey key, Class<T> enumType)` Gets the value for the given key as an enum value.
`static int`	`getInt(PropertyKey key)` Gets the integer representation of the value for the given key.
`static long`	`getLastUpdateTime()`
`static List<String>`	`getList(PropertyKey key)` Gets the value for the given key as a list.
`static long`	`getLong(PropertyKey key)` Gets the long integer representation of the value for the given key.
`static long`	`getMs(PropertyKey key)` Gets the time of key in millisecond unit.
`static Map<String,Object>`	`getNestedProperties(PropertyKey prefixKey)` Gets a set of properties that share a given common prefix key as a map.
`static Object`	`getOrDefault(PropertyKey key, String defaultValue, ConfigurationValueOptions options)`
`static <T> T`	`getOrDefault(PropertyKey key, T defaultValue)`
`static Source`	`getSource(PropertyKey key)`
`static String`	`getString(PropertyKey key)` Gets the String value for the given key.
`static AlluxioConfiguration`	`global()`
`static String`	`hash()`
`static boolean`	`isSet(PropertyKey key)` Checks if the configuration contains a value for the given key.
`static boolean`	`isSetByUser(PropertyKey key)` Checks if the configuration contains a value for the given key that is set by a user.
`static Set<PropertyKey>`	`keySet()`
`static void`	`loadClusterDefaults(InetSocketAddress address, Scope scope)` Loads cluster default values for workers from the meta master if it's not loaded yet.
`static GetConfigurationPResponse`	`loadConfiguration(InetSocketAddress address, AlluxioConfiguration conf, boolean ignoreClusterConf, boolean ignorePathConf)` Loads configuration from meta master in one RPC.
`static void`	`merge(Map<?,?> properties, Source source)` Merges the current configuration properties with new properties.
`static InstancedConfiguration`	`modifiableGlobal()`
`static void`	`reloadProperties()` Reloads site properties from disk.
`static void`	`set(PropertyKey key, Object value)` Sets the value for the appropriate key in the `Properties`.
`static void`	`set(PropertyKey key, Object value, Source source)` Sets the value for the appropriate key in the `Properties` by source.
`static Map<String,Object>`	`toMap()`
`static Map<String,Object>`	`toMap(ConfigurationValueOptions opts)`
`static void`	`unset(PropertyKey key)` Unsets the value for the appropriate key in the `Properties`.

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

- Method Detail
  - copyProperties
```
public static AlluxioProperties copyProperties()
```
    Create and return a copy of all properties.
    
    Returns:
    
    a copy of properties
  - merge
```
public static void merge(Map<?,?> properties,
                         Source source)
```
    Merges the current configuration properties with new properties. If a property exists both in the new and current configuration, the one from the new configuration wins if its priority is higher or equal than the existing one.
    
    Parameters:
    
    properties - the source Properties to be merged
    
    source - the source of the the properties (e.g., system property, default and etc)
  - set
```
public static void set(PropertyKey key,
                       Object value)
```
    Sets the value for the appropriate key in the Properties.
    
    Parameters:
    
    key - the key to set
    
    value - the value for the key
  - set
```
public static void set(PropertyKey key,
                       Object value,
                       Source source)
```
    Sets the value for the appropriate key in the Properties by source.
    
    Parameters:
    
    key - the key to set
    
    value - the value for the key
    
    source - the source of the the properties (e.g., system property, default and etc)
  - unset
```
public static void unset(PropertyKey key)
```
    Unsets the value for the appropriate key in the Properties.
    
    Parameters:
    
    key - the key to unset
  - get
```
public static Object get(PropertyKey key)
```
    Gets the value for the given key in the Properties; if this key is not found, a RuntimeException is thrown.
    
    Parameters:
    
    key - the key to get the value for
    
    Returns:
    
    the value for the given key
  - get
```
public static Object get(PropertyKey key,
                         ConfigurationValueOptions options)
```
    Gets the value for the given key in the Properties; if this key is not found, a RuntimeException is thrown.
    
    Parameters:
    
    key - the key to get the value for
    
    options - options for getting configuration value
    
    Returns:
    
    the value for the given key
  - getOrDefault
```
public static <T> T getOrDefault(PropertyKey key,
                                 T defaultValue)
```
    Type Parameters:
    
    T - the type of default value
    
    Parameters:
    
    key - the key to get the value for
    
    defaultValue - the value to return if no value is set for the specified key
    
    Returns:
    
    the value
  - getOrDefault
```
public static Object getOrDefault(PropertyKey key,
                                  String defaultValue,
                                  ConfigurationValueOptions options)
```
    Parameters:
    
    key - the key to get the value for
    
    defaultValue - the value to return if no value is set for the specified key
    
    options - options for getting configuration value
    
    Returns:
    
    the value
  - isSet
```
public static boolean isSet(PropertyKey key)
```
    Checks if the configuration contains a value for the given key.
    
    Parameters:
    
    key - the key to check
    
    Returns:
    
    true if there is value for the key, false otherwise
  - isSetByUser
```
public static boolean isSetByUser(PropertyKey key)
```
    Checks if the configuration contains a value for the given key that is set by a user.
    
    Parameters:
    
    key - the key to check
    
    Returns:
    
    true if there is value for the key by a user, false otherwise
  - keySet
```
public static Set<PropertyKey> keySet()
```
    Returns:
    
    the keys configured by the configuration
  - getString
```
public static String getString(PropertyKey key)
```
    Gets the String value for the given key.
    
    Parameters:
    
    key - the key to get the value for
    
    Returns:
    
    the value for the given key as an String
  - getInt
```
public static int getInt(PropertyKey key)
```
    Gets the integer representation of the value for the given key.
    
    Parameters:
    
    key - the key to get the value for
    
    Returns:
    
    the value for the given key as an int
  - getDouble
```
public static double getDouble(PropertyKey key)
```
    Gets the double representation of the value for the given key.
    
    Parameters:
    
    key - the key to get the value for
    
    Returns:
    
    the value for the given key as a double
  - getLong
```
public static long getLong(PropertyKey key)
```
    Gets the long integer representation of the value for the given key.
    
    Parameters:
    
    key - the key to get the value for
    
    Returns:
    
    the value for the given key as a long
  - getBoolean
```
public static boolean getBoolean(PropertyKey key)
```
    Gets the boolean representation of the value for the given key.
    
    Parameters:
    
    key - the key to get the value for
    
    Returns:
    
    the value for the given key as a boolean
  - getList
```
public static List<String> getList(PropertyKey key)
```
    Gets the value for the given key as a list.
    
    Parameters:
    
    key - the key to get the value for
    
    Returns:
    
    the list of values for the given key
  - getEnum
```
public static <T extends Enum<T>> T getEnum(PropertyKey key,
                                            Class<T> enumType)
```
    Gets the value for the given key as an enum value.
    
    Type Parameters:
    
    T - the type of the enum
    
    Parameters:
    
    key - the key to get the value for
    
    enumType - the type of the enum
    
    Returns:
    
    the value for the given key as an enum value
  - getBytes
```
public static long getBytes(PropertyKey key)
```
    Gets the bytes of the value for the given key.
    
    Parameters:
    
    key - the key to get the value for
    
    Returns:
    
    the bytes of the value for the given key
  - getMs
```
public static long getMs(PropertyKey key)
```
    Gets the time of key in millisecond unit.
    
    Parameters:
    
    key - the key to get the value for
    
    Returns:
    
    the time of key in millisecond unit
  - getDuration
```
public static java.time.Duration getDuration(PropertyKey key)
```
    Gets the time of the key as a duration.
    
    Parameters:
    
    key - the key to get the value for
    
    Returns:
    
    the value of the key represented as a duration
  - getClass
```
public static <T> Class<T> getClass(PropertyKey key)
```
    Gets the value for the given key as a class.
    
    Type Parameters:
    
    T - the type of the class
    
    Parameters:
    
    key - the key to get the value for
    
    Returns:
    
    the value for the given key as a class
  - getNestedProperties
```
public static Map<String,Object> getNestedProperties(PropertyKey prefixKey)
```
    Gets a set of properties that share a given common prefix key as a map. E.g., if A.B=V1 and A.C=V2, calling this method with prefixKey=A returns a map of {B=V1, C=V2}, where B and C are also valid properties. If no property shares the prefix, an empty map is returned.
    
    Parameters:
    
    prefixKey - the prefix key
    
    Returns:
    
    a map from nested properties aggregated by the prefix
  - getSource
```
public static Source getSource(PropertyKey key)
```
    Parameters:
    
    key - the property key
    
    Returns:
    
    the source for the given key
  - toMap
```
public static Map<String,Object> toMap()
```
    Returns:
    
    a map from all configuration property names to their values; values may potentially be null
  - toMap
```
public static Map<String,Object> toMap(ConfigurationValueOptions opts)
```
    Parameters:
    
    opts - options for formatting the configuration values
    
    Returns:
    
    a map from all configuration property names to their values; values may potentially be null
  - global
```
public static AlluxioConfiguration global()
```
    Returns:
    
    the global configuration through AlluxioConfiguration API, which is a read-only API
  - modifiableGlobal
```
public static InstancedConfiguration modifiableGlobal()
```
    Returns:
    
    the global configuration instance that is modifiable
  - copyGlobal
```
public static InstancedConfiguration copyGlobal()
```
    Returns:
    
    a copy of InstancedConfiguration object based on the global configuration
  - getConfiguration
```
public static List<ConfigProperty> getConfiguration(Scope scope)
```
    Gets all configuration properties filtered by the specified scope.
    
    Parameters:
    
    scope - the scope to filter by
    
    Returns:
    
    the properties
  - loadClusterDefaults
```
public static void loadClusterDefaults(InetSocketAddress address,
                                       Scope scope)
                                throws AlluxioStatusException
```
    Loads cluster default values for workers from the meta master if it's not loaded yet.
    
    Parameters:
    
    address - the master address
    
    scope - the property scope
    
    Throws:
    
    AlluxioStatusException
  - compareAndSetServerConfigReference
```
public static boolean compareAndSetServerConfigReference(InstancedConfiguration conf,
                                                         InstancedConfiguration newConf)
```
    Compares and swap the two conf.
    
    Parameters:
    
    conf - the old config
    
    newConf - the new config
    
    Returns:
    
    whether the compare and set successful
  - loadConfiguration
```
public static GetConfigurationPResponse loadConfiguration(InetSocketAddress address,
                                                          AlluxioConfiguration conf,
                                                          boolean ignoreClusterConf,
                                                          boolean ignorePathConf)
                                                   throws AlluxioStatusException
```
    Loads configuration from meta master in one RPC.
    
    Parameters:
    
    address - the meta master address
    
    conf - the existing configuration
    
    ignoreClusterConf - do not load cluster configuration related information
    
    ignorePathConf - do not load path configuration related information
    
    Returns:
    
    the RPC response
    
    Throws:
    
    AlluxioStatusException
  - getClusterConf
```
public static InstancedConfiguration getClusterConf(GetConfigurationPResponse response,
                                                    AlluxioConfiguration conf,
                                                    Scope scope)
```
    Loads the cluster level configuration from the get configuration response, filters out the configuration for certain scope, and merges it with the existing configuration.
    
    Parameters:
    
    response - the get configuration RPC response
    
    conf - the existing configuration
    
    scope - the target scope
    
    Returns:
    
    the merged configuration
  - hash
```
public static String hash()
```
    Returns:
    
    hash of properties
  - reloadProperties
```
public static void reloadProperties()
```
    Reloads site properties from disk.
  - getLastUpdateTime
```
public static long getLastUpdateTime()
```
    Returns:
    
    the last update time

Class Configuration

Method Summary

Methods inherited from class java.lang.Object

Method Detail

copyProperties

merge

set

set

unset

get

get

getOrDefault

getOrDefault

isSet

isSetByUser

keySet

getString

getInt

getDouble

getLong

getBoolean

getList

getEnum

getBytes

getMs

getDuration

getClass

getNestedProperties

getSource

toMap

toMap

global

modifiableGlobal

copyGlobal

getConfiguration

loadClusterDefaults

compareAndSetServerConfigReference

loadConfiguration

getClusterConf

hash

reloadProperties

getLastUpdateTime