com.metamatrix.common.buffer
Class BufferManagerPropertyNames

java.lang.Object
  com.metamatrix.common.buffer.BufferManagerPropertyNames

public final class BufferManagerPropertyNames
extends java.lang.Object

This class holds constants for all the buffer manager properties.

Field Summary

static java.lang.String	ACTIVE_MEMORY_THRESHOLD Optional property - the percent of buffer management memory that serves as a threshold for active memory management.
static java.lang.String	BUFFER_STORAGE_DIRECTORY Optional property - this value specifies the location to store temporary buffers to large to fit in memory.
static java.lang.String	CONNECTION_DATABASE The environment property name for the name of the metadata store database.
static java.lang.String	CONNECTION_DRIVER The environment property name for the class of the driver.
static java.lang.String	CONNECTION_FACTORY The environment property name for the class that is to be used for the MetadataConnectionFactory implementation.
static java.lang.String	CONNECTION_PASSWORD The environment property name for the password that is to be used for connecting to the metadata store.
static java.lang.String	CONNECTION_POOL_MAXIMUM_AGE The environment property name for the maximum number of milliseconds that a metadata connection may remain unused before it becomes a candidate for garbage collection.
static java.lang.String	CONNECTION_POOL_MAXIMUM_CONCURRENT_USERS The environment property name for the maximum number of concurrent users of a single metadata connection.
static java.lang.String	CONNECTION_PROTOCOL The environment property name for the protocol for connecting to the metadata store.
static java.lang.String	CONNECTION_USERNAME The environment property name for the username that is to be used for connecting to the metadata store.
static java.lang.String	CONNECTOR_BATCH_SIZE Optional property - the max size of a batch sent between connector and query service.
static java.lang.String	LOG_STATS_INTERVAL Optional property - this value specifies how often the buffer statistics should be collected and logged.
static java.lang.String	MANAGEMENT_INTERVAL Optional property - the period between checking whether active memory clean up should occur, in milliseconds.
static java.lang.String	MAX_FILE_SIZE Optional property - this values specifies the maximum size in MegaBytes that a buffer file can reach.
static java.lang.String	MAX_OPEN_FILES Optional property - this values specifies how many open file descriptors should be cached in the storage directory.
static java.lang.String	MEMORY_AVAILABLE Optional property - the amount of memory (in megabytes) that buffer management should use.
static java.lang.String	PROCESSOR_BATCH_SIZE Optional property - the max size of a batch sent internally within the query processor.
static java.lang.String	SESSION_USE_PERCENTAGE Optional property - the percent of buffer management memory that a particular session can use.

Method Summary

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MEMORY_AVAILABLE

public static final java.lang.String MEMORY_AVAILABLE

Optional property - the amount of memory (in megabytes) that buffer management should use. This value should be a positive integer (less than the the max heap size) and defaults to 128.

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Constant Field Values

SESSION_USE_PERCENTAGE

public static final java.lang.String SESSION_USE_PERCENTAGE

Optional property - the percent of buffer management memory that a particular session can use. This property can be used to prevent a single user from consuming too many resources. This value should be in the range [1..100] and defaults to 50.

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Constant Field Values

ACTIVE_MEMORY_THRESHOLD

public static final java.lang.String ACTIVE_MEMORY_THRESHOLD

Optional property - the percent of buffer management memory that serves as a threshold for active memory management. Below the threshold, no active memory management occurs and no data is moved between memory and persistent storage in the background. Above the threshold, a background thread attempts to clean the in-memory buffers using an LRU algorithm. This value should be in the range [1..100] and defaults to 75.

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Constant Field Values

MANAGEMENT_INTERVAL

public static final java.lang.String MANAGEMENT_INTERVAL

Optional property - the period between checking whether active memory clean up should occur, in milliseconds. This value should be a millisecond value and defaults to 500 ms. A value of 0 indicates that no active management should occur.

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Constant Field Values

CONNECTOR_BATCH_SIZE

public static final java.lang.String CONNECTOR_BATCH_SIZE

Optional property - the max size of a batch sent between connector and query service. Making batches larger reduces communication overhead between connector and query service but increases the granularity of memory management on those batches. This value should be a positive integer and defaults to 1000.

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Constant Field Values

PROCESSOR_BATCH_SIZE

public static final java.lang.String PROCESSOR_BATCH_SIZE

Optional property - the max size of a batch sent internally within the query processor. In general, these batches should be smaller than the connector batch size as there are no communication costs with these batches. Smaller batches typically allow a user to get their first results quicker and allow fine-grained buffer management on intermediate results. This value should be a positive integer and defaults to 100.

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Constant Field Values

BUFFER_STORAGE_DIRECTORY

public static final java.lang.String BUFFER_STORAGE_DIRECTORY

Optional property - this value specifies the location to store temporary buffers to large to fit in memory. Temporary buffer files will be created and destroyed in this directory. This value should be a string specifying an absolute directory path.

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Constant Field Values

MAX_OPEN_FILES

public static final java.lang.String MAX_OPEN_FILES

Optional property - this values specifies how many open file descriptors should be cached in the storage directory. Increasing this value in heavy load may improve performance but will use more file descriptors, which are a limited system resource. The default is 10.

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Constant Field Values

MAX_FILE_SIZE

public static final java.lang.String MAX_FILE_SIZE

Optional property - this values specifies the maximum size in MegaBytes that a buffer file can reach. The default is 2048 MB (i.e. 2GB).

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Constant Field Values

LOG_STATS_INTERVAL

public static final java.lang.String LOG_STATS_INTERVAL

Optional property - this value specifies how often the buffer statistics should be collected and logged. This is primarily useful during debugging and defaults to a value of 0, which indicates no stats logging. This value should be either 0 to indicate no logging or a positive integer indicating the period in milliseconds between logging.

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Constant Field Values

CONNECTION_FACTORY

public static final java.lang.String CONNECTION_FACTORY

The environment property name for the class that is to be used for the MetadataConnectionFactory implementation. This property is required (there is no default).

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Constant Field Values

CONNECTION_DRIVER

public static final java.lang.String CONNECTION_DRIVER

The environment property name for the class of the driver. This property is optional.

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Constant Field Values

CONNECTION_PROTOCOL

public static final java.lang.String CONNECTION_PROTOCOL

The environment property name for the protocol for connecting to the metadata store. This property is optional.

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Constant Field Values

CONNECTION_DATABASE

public static final java.lang.String CONNECTION_DATABASE

The environment property name for the name of the metadata store database. This property is optional.

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Constant Field Values

CONNECTION_USERNAME

public static final java.lang.String CONNECTION_USERNAME

The environment property name for the username that is to be used for connecting to the metadata store. This property is optional.

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Constant Field Values

CONNECTION_PASSWORD

public static final java.lang.String CONNECTION_PASSWORD

The environment property name for the password that is to be used for connecting to the metadata store. This property is optional.

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Constant Field Values

CONNECTION_POOL_MAXIMUM_AGE

public static final java.lang.String CONNECTION_POOL_MAXIMUM_AGE

The environment property name for the maximum number of milliseconds that a metadata connection may remain unused before it becomes a candidate for garbage collection. This property is optional.

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Constant Field Values

CONNECTION_POOL_MAXIMUM_CONCURRENT_USERS

public static final java.lang.String CONNECTION_POOL_MAXIMUM_CONCURRENT_USERS

The environment property name for the maximum number of concurrent users of a single metadata connection. This property is optional.

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Constant Field Values