CacheStats (Apache HBase 1.2.12 API)

java.lang.Object
- org.apache.hadoop.hbase.io.hfile.CacheStats

Direct Known Subclasses:

BucketCacheStats, CombinedBlockCache.CombinedCacheStats
```
@InterfaceAudience.Private
public class CacheStats
extends Object
```
Class that implements cache metrics.

Field Summary

Fields
Modifier and Type	Field and Description
`private com.yammer.metrics.core.Histogram`	`ageAtEviction` Keep running age at eviction time
`(package private) static int`	`DEFAULT_WINDOW_PERIODS` Sliding window statistics.
`private AtomicLong`	`evictedBlockCount` The total number of blocks that have been evicted
`private AtomicLong`	`evictionCount` The number of times an eviction has occurred
`private AtomicLong`	`failedInserts` The total number of blocks that were not inserted.
`private AtomicLong`	`hitCachingCount` The number of getBlock requests that were cache hits, but only from requests that were set to use the block cache.
`private long[]`	`hitCachingCounts` Caching hit counts for each period in window
`private AtomicLong`	`hitCount` The number of getBlock requests that were cache hits
`private long[]`	`hitCounts` Hit counts for each period in window
`private long`	`lastHitCachingCount` Last hit caching count read
`private long`	`lastHitCount` Last hit count read
`private long`	`lastRequestCachingCount` Last request caching count read
`private long`	`lastRequestCount` Last request count read
`private static com.yammer.metrics.core.MetricsRegistry`	`METRICS` Needed making histograms.
`private AtomicLong`	`missCachingCount` The number of getBlock requests that were cache misses, but only from requests that were set to use the block cache.
`private AtomicLong`	`missCount` The number of getBlock requests that were cache misses
`private int`	`numPeriodsInWindow` The number of metrics periods to include in window
`private AtomicLong`	`primaryEvictedBlockCount` The total number of blocks for primary replica that have been evicted
`private AtomicLong`	`primaryHitCount` The number of getBlock requests that were cache hits from primary replica
`private AtomicLong`	`primaryMissCount` The number of getBlock requests for primary replica that were cache misses
`private long[]`	`requestCachingCounts` Caching access counts for each period in window
`private long[]`	`requestCounts` Access counts for each period in window
`private long`	`startTime`
`private int`	`windowIndex` Current window index (next to be updated)

Constructor Summary

Constructors
Constructor and Description

CacheStats(String name)

CacheStats(String name, int numPeriodsInWindow)

Constructors
Constructor and Description
`CacheStats(String name)`
`CacheStats(String name, int numPeriodsInWindow)`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`evict()`
`void`	`evicted(long t, boolean primary)`
`double`	`evictedPerEviction()`
`long`	`failInsert()`
`AgeSnapshot`	`getAgeAtEvictionSnapshot()`
`long`	`getEvictedCount()`
`long`	`getEvictionCount()`
`long`	`getFailedInserts()`
`long`	`getHitCachingCount()`
`double`	`getHitCachingRatio()`
`double`	`getHitCachingRatioPastNPeriods()`
`long`	`getHitCount()`
`double`	`getHitRatio()`
`double`	`getHitRatioPastNPeriods()`
`long`	`getMissCachingCount()`
`double`	`getMissCachingRatio()`
`long`	`getMissCount()`
`double`	`getMissRatio()`
`long`	`getPrimaryEvictedCount()`
`long`	`getPrimaryHitCount()`
`long`	`getPrimaryMissCount()`
`long`	`getRequestCachingCount()`
`long`	`getRequestCount()`
`long`	`getSumHitCachingCountsPastNPeriods()`
`long`	`getSumHitCountsPastNPeriods()`
`long`	`getSumRequestCachingCountsPastNPeriods()`
`long`	`getSumRequestCountsPastNPeriods()`
`void`	`hit(boolean caching)`
`void`	`hit(boolean caching, boolean primary)`
`private static long[]`	`initializeZeros(int n)`
`void`	`miss(boolean caching, boolean primary)`
`void`	`rollMetricsPeriod()`
`private static long`	`sum(long[] counts)`
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - METRICS
```
private static final com.yammer.metrics.core.MetricsRegistry METRICS
```
    Needed making histograms.
  - DEFAULT_WINDOW_PERIODS
```
static final int DEFAULT_WINDOW_PERIODS
```
    Sliding window statistics. The number of metric periods to include in sliding window hit ratio calculations.
    
    See Also:
    Constant Field Values
  - hitCount
```
private final AtomicLong hitCount
```
    The number of getBlock requests that were cache hits
  - primaryHitCount
```
private final AtomicLong primaryHitCount
```
    The number of getBlock requests that were cache hits from primary replica
  - hitCachingCount
```
private final AtomicLong hitCachingCount
```
    The number of getBlock requests that were cache hits, but only from requests that were set to use the block cache. This is because all reads attempt to read from the block cache even if they will not put new blocks into the block cache. See HBASE-2253 for more information.
  - missCount
```
private final AtomicLong missCount
```
    The number of getBlock requests that were cache misses
  - primaryMissCount
```
private final AtomicLong primaryMissCount
```
    The number of getBlock requests for primary replica that were cache misses
  - missCachingCount
```
private final AtomicLong missCachingCount
```
    The number of getBlock requests that were cache misses, but only from requests that were set to use the block cache.
  - evictionCount
```
private final AtomicLong evictionCount
```
    The number of times an eviction has occurred
  - evictedBlockCount
```
private final AtomicLong evictedBlockCount
```
    The total number of blocks that have been evicted
  - primaryEvictedBlockCount
```
private final AtomicLong primaryEvictedBlockCount
```
    The total number of blocks for primary replica that have been evicted
  - failedInserts
```
private final AtomicLong failedInserts
```
    The total number of blocks that were not inserted.
  - numPeriodsInWindow
```
private final int numPeriodsInWindow
```
    The number of metrics periods to include in window
  - hitCounts
```
private final long[] hitCounts
```
    Hit counts for each period in window
  - hitCachingCounts
```
private final long[] hitCachingCounts
```
    Caching hit counts for each period in window
  - requestCounts
```
private final long[] requestCounts
```
    Access counts for each period in window
  - requestCachingCounts
```
private final long[] requestCachingCounts
```
    Caching access counts for each period in window
  - lastHitCount
```
private long lastHitCount
```
    Last hit count read
  - lastHitCachingCount
```
private long lastHitCachingCount
```
    Last hit caching count read
  - lastRequestCount
```
private long lastRequestCount
```
    Last request count read
  - lastRequestCachingCount
```
private long lastRequestCachingCount
```
    Last request caching count read
  - windowIndex
```
private int windowIndex
```
    Current window index (next to be updated)
  - ageAtEviction
```
private com.yammer.metrics.core.Histogram ageAtEviction
```
    Keep running age at eviction time
  - startTime
```
private long startTime
```
- Constructor Detail
  - CacheStats
```
public CacheStats(String name)
```
  - CacheStats
```
public CacheStats(String name,
          int numPeriodsInWindow)
```
- Method Detail
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - miss
```
public void miss(boolean caching,
        boolean primary)
```
  - hit
```
public void hit(boolean caching)
```
  - hit
```
public void hit(boolean caching,
       boolean primary)
```
  - evict
```
public void evict()
```
  - evicted
```
public void evicted(long t,
           boolean primary)
```
  - failInsert
```
public long failInsert()
```
  - getRequestCount
```
public long getRequestCount()
```
  - getRequestCachingCount
```
public long getRequestCachingCount()
```
  - getMissCount
```
public long getMissCount()
```
  - getPrimaryMissCount
```
public long getPrimaryMissCount()
```
  - getMissCachingCount
```
public long getMissCachingCount()
```
  - getHitCount
```
public long getHitCount()
```
  - getPrimaryHitCount
```
public long getPrimaryHitCount()
```
  - getHitCachingCount
```
public long getHitCachingCount()
```
  - getEvictionCount
```
public long getEvictionCount()
```
  - getEvictedCount
```
public long getEvictedCount()
```
  - getPrimaryEvictedCount
```
public long getPrimaryEvictedCount()
```
  - getHitRatio
```
public double getHitRatio()
```
  - getHitCachingRatio
```
public double getHitCachingRatio()
```
  - getMissRatio
```
public double getMissRatio()
```
  - getMissCachingRatio
```
public double getMissCachingRatio()
```
  - evictedPerEviction
```
public double evictedPerEviction()
```
  - getFailedInserts
```
public long getFailedInserts()
```
  - rollMetricsPeriod
```
public void rollMetricsPeriod()
```
  - getSumHitCountsPastNPeriods
```
public long getSumHitCountsPastNPeriods()
```
  - getSumRequestCountsPastNPeriods
```
public long getSumRequestCountsPastNPeriods()
```
  - getSumHitCachingCountsPastNPeriods
```
public long getSumHitCachingCountsPastNPeriods()
```
  - getSumRequestCachingCountsPastNPeriods
```
public long getSumRequestCachingCountsPastNPeriods()
```
  - getHitRatioPastNPeriods
```
public double getHitRatioPastNPeriods()
```
  - getHitCachingRatioPastNPeriods
```
public double getHitCachingRatioPastNPeriods()
```
  - getAgeAtEvictionSnapshot
```
public AgeSnapshot getAgeAtEvictionSnapshot()
```
  - sum
```
private static long sum(long[] counts)
```
  - initializeZeros
```
private static long[] initializeZeros(int n)
```

Class CacheStats

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

METRICS

DEFAULT_WINDOW_PERIODS

hitCount

primaryHitCount

hitCachingCount

missCount

primaryMissCount

missCachingCount

evictionCount

evictedBlockCount

primaryEvictedBlockCount

failedInserts

numPeriodsInWindow

hitCounts

hitCachingCounts

requestCounts

requestCachingCounts

lastHitCount

lastHitCachingCount

lastRequestCount

lastRequestCachingCount

windowIndex

ageAtEviction

startTime

Constructor Detail

CacheStats

CacheStats

Method Detail

toString

miss

hit

hit

evict

evicted

failInsert

getRequestCount

getRequestCachingCount

getMissCount

getPrimaryMissCount

getMissCachingCount

getHitCount

getPrimaryHitCount

getHitCachingCount

getEvictionCount

getEvictedCount

getPrimaryEvictedCount

getHitRatio

getHitCachingRatio

getMissRatio

getMissCachingRatio

evictedPerEviction

getFailedInserts

rollMetricsPeriod

getSumHitCountsPastNPeriods

getSumRequestCountsPastNPeriods

getSumHitCachingCountsPastNPeriods

getSumRequestCachingCountsPastNPeriods

getHitRatioPastNPeriods

getHitCachingRatioPastNPeriods

getAgeAtEvictionSnapshot

sum

initializeZeros