VMware GemFire Java API Reference
Package org.apache.geode
The base package of the GemFire Java product, featuring highly concurrent distributed caching with cache event delivery, OQL querying, and remote cache administration, built using a DistributedSystem which includes a DistributedLockService.
This package contains classes that are used throughout GemFire,
providing enhanced serialization performance using the DataSerializable feature and the ability to
profile your GemFire application using a handy Statistics infrastructure.
GemFire Statistics
The ability to monitor and analyze the behavior and performance of an application can ease the job of optimization. To aid in this analysis, GemFire provides the ability to register and capture application statistics. An application statistic is simply a number that the application is free to modify and that is monitored by the GemFire's statistics collector. The statistics may be monitored at runtime using the Admin API or GemFire JMX Agent.
Each application statistic is described by a
StatisticDescriptor instance.
Logical groupings of application statistics are described by a
StatisticsType instance that contains the name
and description of each statistic. Each instance of an type
is represented by an instance of
Statistics.
The descriptors,
types, and
instances are created using an
instance of the StatisticsFactory interface.
Each statistics instance
(there may be multiple instances of a statistics type) can be identified
by a text id
and/or a numeric id.
The name, description, etc. of the statistic and its type
are available in the Admin API or GemFire JMX Agent.
An application can get, set, and increment the value of a statistic
using methods of the Statistics interface. If statistics
sampling has been enabled
a thread in the application VM periodically
reads the values of application statistics allowing them to be viewed
by the Admin API and GemFire JMX Agent. Statistics may also be archived
to a file, the name
and location of which may be configured when creating a DistributedSystem.
In addition to application statistics, GemFire maintains statistics about the distributed system, the distributed cache, and the physical machine on which it runs. These statistics can be monitored, viewed, and archived just like application statistics.
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ClassDescriptionAbstract cancellation proxy for cancelling an operation, esp.Abstract root class of all GemFire exceptions representing system cancellation
CanonicalInstantiatoris much like its parentInstantiatorexcept that instead of needing to implementnewInstance()you now must implementnewInstance(DataInput).Indicates a failure to copy an object.A static helper for optimally creating copies.An interface for objects whose state can be written/read as primitive types and strings ("data").Replaceableallows an object to write an alternative version of itself to aDataOutput.Provides static helper methods for reading and writing non-primitive data when working with aDataSerializable.This interface defines a contract between the application and GemFire that allows GemFire to determine whether an application object contains a delta, allows GemFire to extract the delta from an application object, and generate a new application object by applying a delta to an existing application object.This exception wraps any checked exception encountered during invocation ofDelta.fromDelta(java.io.DataInput)orDelta.toDelta(java.io.DataOutput)in GemFire.AnForcedDisconnectExceptionis thrown when a GemFire application is removed from the distributed system due to membership constraints such as network partition detection.AnGemFireCacheExceptionis used to wrap aCacheException.This is the abstract superclass of exceptions that are thrown and declared.AGemFireConfigExceptionis used for failures while processing a GemFire configuration XML file.This is the abstract superclass of exceptions that are thrown to indicate incorrect usage of GemFire.AGemFireIOExceptionis thrown when a GemFire operation failure is caused by anIOException.This error is used by GemFire for internal purposes.AnIncompatibleSystemExceptionis thrown when a new GemFire process tries to connect to an existing distributed system and its version is not the same as that of the distributed system.Instantiatorallows classes that implementDataSerializableto be registered with the data serialization framework.Indicates that serious error has occurred within the GemFire system.AnInternalGemFireExceptionis thrown when a low level, internal, operation fails due to no fault of the user.AnInvalidDeltaExceptionis thrown when a delta cannot be successfully applied by the receiving peer/client.AnInvalidValueExceptionis thrown when an attempt is made to set a configuration attribute to an invalid value is made.Deprecated.Please use Log4J2 instead.ANoSystemExceptionis thrown when a locator can not be found or connected to.Indicates that attempts to allocate more objects in off-heap memory has failed and the Cache will be closed to prevent it from losing distributed consistency.An exception indicating that a serialization or deserialization failed.Describes an individual statistic whose value is updated by an application and may be archived by GemFire.Instances of this interface maintain the values of various application-defined statistics.Instances of this interface provide methods that create instances ofStatistics.Used to describe a logical collection of statistics.Instances of this interface provide methods that create instances ofStatisticDescriptorandStatisticsType.AnSystemConnectExceptionis thrown when a GemFire application tries to connect to an existing distributed system and is unable to contact all members of the distributed system to announce its presence.Deprecated.since Geode 1.11 because it is potentially counterproductive to try to mitigate a VirtualMachineError since the JVM (spec) makes no guarantees about the soundness of the JVM after such an error.ASystemIsRunningExceptionis thrown when an operation is attempted that requires that the locator is stopped.AToDataExceptionis thrown during serialization ifDataSerializable.toData(java.io.DataOutput)throws an exception or ifDataSerializer.toData(java.lang.Object, java.io.DataOutput)is called and returns false.AnUncreatedSystemExceptionis thrown when the specified locator's directory or configuration file can not be found.AUnmodifiableExceptionis thrown when a an attempt is made to modify a GemFire member configuration attribute that can not currently be modified.AnUnstartedSystemExceptionis thrown when the specified locator exists but is not running or could not be connected to.