Examples of com.sleepycat.je.EnvironmentConfig

• com.sleepycat.je.EnvironmentConfig
  omize an environment configuration EnvironmentConfig envConfig = new EnvironmentConfig(); // will throw if timeout value is invalid envConfig.setLockTimeout(250, TimeUnit.MILLISECONDS); // Open the environment using this configuration. Environment myEnvironment = new Environment(home, envConfig);

  Additional parameters are described by the parameter name String constants in this class. These additional parameters will not be needed by most applications. This category of properties can be specified for the EnvironmentConfig object through a Properties object read by EnvironmentConfig(Properties), or individually through EnvironmentConfig.setConfigParam().

  For example, an application can change the default btree node size with:

   envConfig.setConfigParam(EnvironmentConfig.NODE_MAX_ENTRIES, "256"); 

  Environment configuration follows this order of precedence:

  1. Configuration parameters specified in <environment home>/je.properties take first precedence.
  2. Configuration parameters set in the EnvironmentConfig object used at Environment construction are next.
  3. Any configuration parameters not set by the application are set to system defaults, described along with the parameter name String constants in this class.

  An EnvironmentConfig can be used to specify both mutable and immutable environment properties. Immutable properties may be specified when the first Environment handle (instance) is opened for a given physical environment. When more handles are opened for the same environment, the following rules apply:

  1. Immutable properties must equal the original values specified when constructing an Environment handle for an already open environment. When a mismatch occurs, an exception is thrown.
  2. Mutable properties are ignored when constructing an Environment handle for an already open environment.

  After an Environment has been constructed, its mutable properties may be changed using {@link Environment#setMutableConfig}. See {@link EnvironmentMutableConfig} for a list of mutable properties; all otherproperties are immutable. Whether a property is mutable or immutable is also described along with the parameter name String constants in this class.

  Getting the Current Environment Properties

  To get the current "live" properties of an environment after constructing it or changing its properties, you must call {@link Environment#getConfig} or{@link Environment#getMutableConfig}. The original EnvironmentConfig or EnvironmentMutableConfig object used to set the properties is not kept up to date as properties are changed, and does not reflect property validation or properties that are computed.

  Time Duration Properties

  Several environment and transaction configuration properties are time durations. For these properties, a time unit is specified along with an integer duration value.

  When specific setter and getter methods exist for a time duration property, these methods have a {@link TimeUnit} argument. Examples are{@link #setLockTimeout(long,TimeUnit)} and {@link #getLockTimeout(TimeUnit)}. Note that the {@link TimeUnit} argument maybe null only when the duration value is zero; there is no default unit that is used when null is specified.

  When a time duration is specified as a string value, the following format is used.

      {@code  [   ]}

  The {@code } is an integer. The {@code } name, if present,must be preceded by one or more spaces or tabs.

  The following {@code } names are allowed. Both {@link TimeUnit}names and IEEE standard abbreviations are allowed. Unit names are case insensitive.

  IEEE abbreviation	TimeUnit name	Definition
  {@code ns}	{@code NANOSECONDS}	one billionth (10-9) of a second
  {@code us}	{@code MICROSECONDS}	one millionth (10-6) of a second
  {@code ms}	{@code MILLISECONDS}	one thousandth (10-3) of a second
  {@code s}	{@code SECONDS}	1 second
  {@code min}		60 seconds
  {@code h}		3600 seconds

  Examples are:

   3 seconds 3 s 500 ms 1000000 (microseconds is implied) 

  Note that when the {@code } is omitted, microseconds is implied.This default is supported for compatibility with JE 3.3 and earlier. In JE 3.3 and earlier, explicit time units were not used and durations were always implicitly specified in microseconds. The older methods that do not have a {@link TimeUnit} argument, such as {@link #setLockTimeout(long)} and {@link #getLockTimeout()}, use microsecond durations and have been deprecated.

Related Classes of com.sleepycat.je.EnvironmentConfig