DataRegionMetrics (Ignite 2.7.2)

All Known Subinterfaces:

DataRegionMetricsMXBean
```
public interface DataRegionMetrics
```
This interface provides page memory related metrics of a specific Apache Ignite node. The overall page memory architecture is covered in DataStorageConfiguration.
Since there are can be several memory regions configured with DataRegionConfiguration on an individual Apache Ignite node, the metrics for every region will be collected and obtained separately.
There are two ways to get the metrics of an Apache Ignite node.
1. First, a collection of the metrics can be obtained through Ignite.dataRegionMetrics() method. Note that the method returns data region metrics snapshots rather than just in time memory state.
2. Second, all DataRegionMetrics of a local Apache Ignite node are visible through JMX interface. Refer to DataRegionMetricsMXBean for more details.
Data region metrics collection is not a free operation and might affect performance of an application. This is the reason why the metrics are turned off by default. To enable the collection you can use both DataRegionConfiguration.setMetricsEnabled(boolean) configuration property or DataRegionMetricsMXBean.enableMetrics() method of a respective JMX bean.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and 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()` Gets the percentage of the used space.
`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`	`getUsedCheckpointBufferPages()` Gets used checkpoint buffer size in pages.
`long`	`getUsedCheckpointBufferSize()` Gets used checkpoint buffer size in bytes.

- Method Detail
  - getName
```
String getName()
```
    A name of a memory region the metrics are collected for.
    
    Returns:
    
    Name of the memory region.
  - getTotalAllocatedPages
```
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.
    
    Returns:
    
    Total number of allocated pages.
  - getTotalAllocatedSize
```
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.
    
    Returns:
    
    Total size of memory allocated, in bytes.
  - getAllocationRate
```
float getAllocationRate()
```
    Gets pages allocation rate of a memory region.
    
    Returns:
    
    Number of allocated pages per second.
  - getEvictionRate
```
float getEvictionRate()
```
    Gets eviction rate of a given memory region.
    
    Returns:
    
    Number of evicted pages per second.
  - getLargeEntriesPagesPercentage
```
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.
    
    Returns:
    
    Percentage of pages fully occupied by large entities.
  - getPagesFillFactor
```
float getPagesFillFactor()
```
    Gets the percentage of the used space.
    
    Returns:
    
    The percentage of the used space.
  - getDirtyPages
```
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.
    
    Returns:
    
    Current number of dirty pages.
  - getPagesReplaceRate
```
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.
    
    Returns:
    
    Pages per second replace rate.
  - getPagesReplaceAge
```
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.
    
    Returns:
    
    Replaced pages age in milliseconds.
  - getPhysicalMemoryPages
```
long getPhysicalMemoryPages()
```
    Gets total number of pages currently loaded to the RAM. When persistence is disabled, this metric is equal to getTotalAllocatedPages().
    
    Returns:
    
    Total number of pages loaded to RAM.
  - getPhysicalMemorySize
```
long getPhysicalMemorySize()
```
    Gets total size of pages loaded to the RAM. When persistence is disabled, this metric is equal to getTotalAllocatedSize().
    
    Returns:
    
    Total size of pages loaded to RAM in bytes.
  - getUsedCheckpointBufferPages
```
long getUsedCheckpointBufferPages()
```
    Gets used checkpoint buffer size in pages.
    
    Returns:
    
    Checkpoint buffer size in pages.
  - getUsedCheckpointBufferSize
```
long getUsedCheckpointBufferSize()
```
    Gets used checkpoint buffer size in bytes.
    
    Returns:
    
    Checkpoint buffer size in bytes.
  - getCheckpointBufferSize
```
long getCheckpointBufferSize()
```
    Gets checkpoint buffer size in bytes.
    
    Returns:
    
    Checkpoint buffer size in bytes.
  - getPageSize
```
int getPageSize()
```
    Gets memory page size.
    
    Returns:
    
    Page size in bytes.
  - getPagesRead
```
long getPagesRead()
```
    The number of read pages from last restart.
    
    Returns:
    
    The number of read pages from last restart.
  - getPagesWritten
```
long getPagesWritten()
```
    The number of written pages from last restart.
    
    Returns:
    
    The number of written pages from last restart.
  - getPagesReplaced
```
long getPagesReplaced()
```
    The number of replaced pages from last restart .
    
    Returns:
    
    The number of replaced pages from last restart .
  - getOffHeapSize
```
long getOffHeapSize()
```
    Total offheap size in bytes.
    
    Returns:
    
    Total offheap size in bytes.
  - getOffheapUsedSize
```
long getOffheapUsedSize()
```
    Total used offheap size in bytes.
    
    Returns:
    
    Total used offheap size in bytes.

Interface DataRegionMetrics

Method Summary

Method Detail

getName

getTotalAllocatedPages

getTotalAllocatedSize

getAllocationRate

getEvictionRate

getLargeEntriesPagesPercentage

getPagesFillFactor

getDirtyPages

getPagesReplaceRate

getPagesReplaceAge

getPhysicalMemoryPages

getPhysicalMemorySize

getUsedCheckpointBufferPages

getUsedCheckpointBufferSize

getCheckpointBufferSize

getPageSize

getPagesRead

getPagesWritten

getPagesReplaced

getOffHeapSize

getOffheapUsedSize