Package org.apache.ignite.internal.processors.cache.persistence

Class DataRegionMetricsSnapshot

java.lang.Object

org.apache.ignite.internal.processors.cache.persistence.DataRegionMetricsSnapshot

All Implemented Interfaces:

DataRegionMetrics

public class DataRegionMetricsSnapshot
extends Object
implements DataRegionMetrics

Constructor Summary

Constructors

Constructor	Description
DataRegionMetricsSnapshot(DataRegionMetrics metrics)

Method Summary

Modifier and Type	Method	Description
float	getAllocationRate()	Gets pages allocation rate of a memory region.
long	getCheckpointBufferSize()	Gets checkpoint buffer size in bytes.
long	getDirtyPages()	Gets the number of dirty pages (pages which contents is different from the current persistent storage state).
float	getEvictionRate()	Gets eviction rate of a given memory region.
float	getLargeEntriesPagesPercentage()	Gets percentage of pages that are fully occupied by large entries that go beyond page size.
String	getName()	A name of a memory region the metrics are collected for.
long	getOffHeapSize()	Total offheap size in bytes.
long	getOffheapUsedSize()	Total used offheap size in bytes.
float	getPagesFillFactor()	Returns the ratio of space occupied by user and system data to the size of all pages that contain this data.
int	getPageSize()	Gets memory page size.
long	getPagesRead()	The number of read pages from last restart.
float	getPagesReplaceAge()	Gets average age (in milliseconds) for the pages being replaced from the disk storage.
long	getPagesReplaced()	The number of replaced pages from last restart .
float	getPagesReplaceRate()	Gets rate (pages per second) at which pages get replaced with other pages from persistent storage.
long	getPagesWritten()	The number of written pages from last restart.
long	getPhysicalMemoryPages()	Gets total number of pages currently loaded to the RAM.
long	getPhysicalMemorySize()	Gets total size of pages loaded to the RAM.
long	getTotalAllocatedPages()	Gets a total number of allocated pages related to the data region.
long	getTotalAllocatedSize()	Gets a total size of memory allocated in the data region.
long	getTotalUsedPages()	Gets a total number of pages used for storing the data.
long	getTotalUsedSize()	Returns the total amount of bytes occupied by the non-empty pages.
long	getUsedCheckpointBufferPages()	Gets used checkpoint buffer size in pages.
long	getUsedCheckpointBufferSize()	Gets used checkpoint buffer size in bytes.

Methods inherited from class java.lang.Object

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

Constructor Detail

DataRegionMetricsSnapshot

public DataRegionMetricsSnapshot(DataRegionMetrics metrics)

Parameters:

metrics - Metrics instance to take a copy.

Method Detail

getName

public String getName()

A name of a memory region the metrics are collected for.

Specified by:

getName in interface DataRegionMetrics

Returns:

Name of the memory region.

getTotalAllocatedPages

public long getTotalAllocatedPages()

Gets a total number of allocated pages related to the data region. When persistence is disabled, this metric shows the total number of pages in memory. When persistence is enabled, this metric shows the total number of pages in memory and on disk.

Specified by:

getTotalAllocatedPages in interface DataRegionMetrics

Returns:

Total number of allocated pages.

getTotalAllocatedSize

public long getTotalAllocatedSize()

Gets a total size of memory allocated in the data region. When persistence is disabled, this metric shows the total size of pages in memory. When persistence is enabled, this metric shows the total size of pages in memory and on disk.

Specified by:

getTotalAllocatedSize in interface DataRegionMetrics

Returns:

Total size of memory allocated, in bytes.

getTotalUsedPages

public long getTotalUsedPages()

Gets a total number of pages used for storing the data. It includes allocated pages except of empty pages that are not used yet or pages that can be reused.

E. g. data region contains 1000 allocated pages, and 200 pages are used to store some data, this metric shows 200 used pages. Then the data was partially deleted and 50 pages were totally freed, hence this metric should show 150 used pages.

Specified by:

getTotalUsedPages in interface DataRegionMetrics

Returns:

Total number of used pages.

getTotalUsedSize

public long getTotalUsedSize()

Returns the total amount of bytes occupied by the non-empty pages. This value is directly tied to the DataRegionMetrics.getTotalUsedPages() and does not take page fragmentation into account (i.e. if some data is removed from a page, but it is not completely empty, it will still show the whole page bytes as being occupied).

Specified by:

getTotalUsedSize in interface DataRegionMetrics

Returns:

Total amount of bytes occupied by the non-empty pages

getAllocationRate

public float getAllocationRate()

Gets pages allocation rate of a memory region.

Specified by:

getAllocationRate in interface DataRegionMetrics

Returns:

Number of allocated pages per second.

getEvictionRate

public float getEvictionRate()

Gets eviction rate of a given memory region.

Specified by:

getEvictionRate in interface DataRegionMetrics

Returns:

Number of evicted pages per second.

getLargeEntriesPagesPercentage

public float getLargeEntriesPagesPercentage()

Gets percentage of pages that are fully occupied by large entries that go beyond page size. The large entities are split into fragments in a way so that each fragment can fit into a single page.

Specified by:

getLargeEntriesPagesPercentage in interface DataRegionMetrics

Returns:

Percentage of pages fully occupied by large entities.

getPagesFillFactor

public float getPagesFillFactor()

Returns the ratio of space occupied by user and system data to the size of all pages that contain this data.

This metric can help to determine how much space of a data page is occupied on average. Low fill factor can indicate that data pages are very fragmented (i.e. there is a lot of empty space across all data pages).

Specified by:

getPagesFillFactor in interface DataRegionMetrics

Returns:

Ratio of space occupied by user and system data to the size of all pages that contain ant data.

getDirtyPages

public long getDirtyPages()

Gets the number of dirty pages (pages which contents is different from the current persistent storage state). This metric is enabled only for Ignite nodes with enabled persistence.

Specified by:

getDirtyPages in interface DataRegionMetrics

Returns:

Current number of dirty pages.

getPagesReplaceRate

public float getPagesReplaceRate()

Gets rate (pages per second) at which pages get replaced with other pages from persistent storage. The rate effectively represents the rate at which pages get 'evicted' in favor of newly needed pages. This metric is enabled only for Ignite nodes with enabled persistence.

Specified by:

getPagesReplaceRate in interface DataRegionMetrics

Returns:

Pages per second replace rate.

getPagesReplaceAge

public float getPagesReplaceAge()

Gets average age (in milliseconds) for the pages being replaced from the disk storage. This number effectively represents the average time between the moment when a page is read from the disk and the time when the page is evicted. Note that if a page is never evicted, it does not contribute to this metric. This metric is enabled only for Ignite nodes with enabled persistence.

Specified by:

getPagesReplaceAge in interface DataRegionMetrics

Returns:

Replaced pages age in milliseconds.

getPhysicalMemoryPages

public long getPhysicalMemoryPages()

Gets total number of pages currently loaded to the RAM. When persistence is disabled, this metric is equal to DataRegionMetrics.getTotalAllocatedPages().

Specified by:

getPhysicalMemoryPages in interface DataRegionMetrics

Returns:

Total number of pages loaded to RAM.

getPhysicalMemorySize

public long getPhysicalMemorySize()

Gets total size of pages loaded to the RAM. When persistence is disabled, this metric is equal to DataRegionMetrics.getTotalAllocatedSize().

Specified by:

getPhysicalMemorySize in interface DataRegionMetrics

Returns:

Total size of pages loaded to RAM in bytes.

getUsedCheckpointBufferPages

public long getUsedCheckpointBufferPages()

Gets used checkpoint buffer size in pages.

Specified by:

getUsedCheckpointBufferPages in interface DataRegionMetrics

Returns:

Checkpoint buffer size in pages.

getUsedCheckpointBufferSize

public long getUsedCheckpointBufferSize()

Gets used checkpoint buffer size in bytes.

Specified by:

getUsedCheckpointBufferSize in interface DataRegionMetrics

Returns:

Checkpoint buffer size in bytes.

getCheckpointBufferSize

public long getCheckpointBufferSize()

Gets checkpoint buffer size in bytes.

Specified by:

getCheckpointBufferSize in interface DataRegionMetrics

Returns:

Checkpoint buffer size in bytes.

getPageSize

public int getPageSize()

Gets memory page size.

Specified by:

getPageSize in interface DataRegionMetrics

Returns:

Page size in bytes.

getPagesRead

public long getPagesRead()

The number of read pages from last restart.

Specified by:

getPagesRead in interface DataRegionMetrics

Returns:

The number of read pages from last restart.

getPagesWritten

public long getPagesWritten()

The number of written pages from last restart.

Specified by:

getPagesWritten in interface DataRegionMetrics

Returns:

The number of written pages from last restart.

getPagesReplaced

public long getPagesReplaced()

The number of replaced pages from last restart .

Specified by:

getPagesReplaced in interface DataRegionMetrics

Returns:

The number of replaced pages from last restart .

getOffHeapSize

public long getOffHeapSize()

Total offheap size in bytes.

Specified by:

getOffHeapSize in interface DataRegionMetrics

Returns:

Total offheap size in bytes.

getOffheapUsedSize

public long getOffheapUsedSize()

Total used offheap size in bytes.

Specified by:

getOffheapUsedSize in interface DataRegionMetrics

Returns:

Total used offheap size in bytes.