edu.upc.dama.dex.utils
Class DEXConfig

java.lang.Object
  java.util.Dictionary
      java.util.Hashtable
          java.util.Properties
              edu.upc.dama.dex.utils.DEXConfig

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.util.Map

public class DEXConfig
extends java.util.Properties

Runtime configuration settings for the DEX framework.

Maintains a set of hardwired configuration settings that can be overrriden by creating a text properties file containing custom values. By default, DEX will look for the file "dex.cfg" in the current working directory for configuration name/value pairs. The framework can be instructed to look for a different file by putting the full path to the file into the "dex.config" System property (for example by using a -D flag at the Java runtime command line).

Some of the supported configuration properties include:

• dex.io.cache.maxsize - Maximum Cache (total pools) size in MB. 0 means unlimited. The default setting is 0.
• dex.monitor.active - Activate the remote monitor. It is necessary to use DEXAdmin. The default setting is false.
• dex.monitor.port - Port used by the monitor for the remote connections. The default setting is 9999.
• dex.tasks.workers - Number of workers to be used by the task Scheduler (Scheduler). The default setting is 1.
• dex.license - License code. The default setting is "", which means evaluation version.
• dex.log - Log traces. It is possible to specify a log level and an output file. Allowed log levels, from lower to higher, are: OFF, SEVERE, WARNING, INFO, CONFIG and FINE. The higher the level the more log traces we get. Specifically, OFF disables all log traces. For the output file a relative or full path ca be given. The default setting is "INFO;jdex.log".
• dex.io.recovery - Enable ("true") or ("disable") recovery. If disabled, all other recovery variables are ignored. Value format: string. Default value: "false"
• dex.io.recovery.logfile - Recovery log file. Empty string means the recovery log file will be the same as the database path plus ".log". Example: if the database is at "gdb.dex" then the recovery log file will be "gdb.dex.log". Value format: string. Default value: ""
• dex.io.recovery.cachesize - Maximum size for the recovery cache in MBs. Value format: number. Default value: 1
• dex.io.recovery.checkpointTime - Checkpoint frequency for the recovery cache. Value format: time unit. Default value: 60
• dex.ha - Enables or disables HA mode. If disabled, all other HA variables are ignored. Value format: string. Default value: false
• dex.ha.ip - IP address and port for the instance. It must be given as follows: `ip:port` Value format: string. Default value: `localhost:7777`
• dex.ha.coordinators - Comma-separated list of the ZooKeeper instances. For each instance, the IP address and the port must be given as follows: `ip:port`. Moreover, the port must correspond to the given as `clientPort` in the ZooKeeper configuration file. Value format: string. Default value: ""
• dex.ha.sync - Synchronization polling time. If 0, polling is disabled and synchronization is only performed when the slave receives a write request, otherwise the parameter fixes the frequency the slaves poll the master asking for writes. The polling timer is reset if the slaves receives a write request, as it synchronizes then. Value format: time unit. Default value: 0.
• dex.ha.master.history - The history log is limited to a certain period of time, so writes occurred beyond that period of time will be removed from it and the master will not accept requests from those deleted DEX slaves. For example, in case of `12H`, the master will store in the history log all write operations during the last 12 hours. It will reject requests from a slave which has not been up-to-date in the last 12 hours. Value format: time unit. Default value: 1D

Application creators are welcome to add their own custom properties to the configuration files and use the DEXConfig instance to access those properties.

This class is a singleton, accessed through a static accessor method.

See Also:

Serialized Form

Author:

Sparsity Technologies

Field Summary

Fields inherited from class java.util.Properties

defaults

Method Summary

static java.lang.String	get(java.lang.String key) Gets a DEX configuration property.
static boolean	getBoolean(java.lang.String key) Gets a DEX configuration property as a boolean.
static DEXConfig	getConfig() Gets the global DEXConfig instance.
static double	getDouble(java.lang.String key) Gets a DEX configuration property as a double.
static float	getFloat(java.lang.String key) Gets a DEX configuration property as a float.
static int	getInt(java.lang.String key) Gets a DEX configuration property as an integer.
static long	getLong(java.lang.String key) Gets a DEX configuration property as a long.
static void	set(java.lang.String key, java.lang.String value) Sets a DEX configuration property.

Methods inherited from class java.util.Properties

getProperty, getProperty, list, list, load, load, loadFromXML, propertyNames, save, setProperty, store, store, storeToXML, storeToXML, stringPropertyNames

Methods inherited from class java.util.Hashtable

clear, clone, contains, containsKey, containsValue, elements, entrySet, equals, get, hashCode, isEmpty, keys, keySet, put, putAll, rehash, remove, size, toString, values

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

getConfig

public static DEXConfig getConfig()

Gets the global DEXConfig instance.

Returns:

The configuration instance.

get

public static java.lang.String get(java.lang.String key)

Gets a DEX configuration property.

Parameters:

key - the name of the property to lookup.

Returns:

the property value, or null if the key is not found.

getInt

public static int getInt(java.lang.String key)

Gets a DEX configuration property as an integer.

Parameters:

key - the name of the property to lookup.

Returns:

the property value, or the minimum possible integer value if the key is not found or parsing of the number fails.

getLong

public static long getLong(java.lang.String key)

Gets a DEX configuration property as a long.

Parameters:

key - the name of the property to lookup.

Returns:

the property value, or the minimum possible long value if the key is not found or parsing of the number fails.

getFloat

public static float getFloat(java.lang.String key)

Gets a DEX configuration property as a float.

Parameters:

key - the name of the property to lookup.

Returns:

the property value, or a Float.NaN. value if the key is not found or parsing of the number fails.

getDouble

public static double getDouble(java.lang.String key)

Gets a DEX configuration property as a double.

Parameters:

key - the name of the property to lookup.

Returns:

the property value, or a Double.NaN value if the key is not found or parsing of the number fails.

getBoolean

public static boolean getBoolean(java.lang.String key)

Gets a DEX configuration property as a boolean.

Parameters:

key - the name of the property to lookup.

Returns:

the property value. False is returned if the key is not found or does not parse to a true/false value.

set

public static void set(java.lang.String key,
                       java.lang.String value)

Sets a DEX configuration property.

Parameters:

key - the name of the property.

value - the value of the property.