com.datastax.driver.core

Class QueryLogger.DynamicThresholdQueryLogger

java.lang.Object

com.datastax.driver.core.QueryLogger

com.datastax.driver.core.QueryLogger.DynamicThresholdQueryLogger

All Implemented Interfaces:

LatencyTracker, LifecycleAwareLatencyTracker

Enclosing class:

QueryLogger

public static class QueryLogger.DynamicThresholdQueryLogger
extends QueryLogger

A QueryLogger that uses a dynamic threshold in milliseconds to track slow queries.

Dynamic thresholds are based on per-host latency percentiles, as computed by PercentileTracker.

Nested Class Summary

Nested classes/interfaces inherited from class com.datastax.driver.core.QueryLogger

QueryLogger.Builder, QueryLogger.ConstantThresholdQueryLogger, QueryLogger.DynamicThresholdQueryLogger

Field Summary

Fields inherited from class com.datastax.driver.core.QueryLogger

cluster, DEFAULT_MAX_LOGGED_PARAMETERS, DEFAULT_MAX_PARAMETER_VALUE_LENGTH, DEFAULT_MAX_QUERY_STRING_LENGTH, DEFAULT_SLOW_QUERY_THRESHOLD_MS, DEFAULT_SLOW_QUERY_THRESHOLD_PERCENTILE, ERROR_LOGGER, maxLoggedParameters, maxParameterValueLength, maxQueryStringLength, NORMAL_LOGGER, SLOW_LOGGER

Method Summary

Modifier and Type	Method and Description
PercentileTracker	getPercentileLatencyTracker() Return the percentile tracker to use for recording per-host latency histograms.
double	getSlowQueryLatencyThresholdPercentile() Return the threshold percentile beyond which queries are considered 'slow' and logged as such by the driver.
protected void	maybeLogNormalOrSlowQuery(Host host, Statement statement, long latencyMs)
protected void	maybeLogSlowQuery(Host host, Statement statement, long latencyMs, long threshold)
void	onRegister(Cluster cluster) Gets invoked when the tracker is registered with a cluster, or at cluster startup if the tracker was registered at initialization with Cluster.register(LatencyTracker).
void	onUnregister(Cluster cluster) Gets invoked when the tracker is unregistered from a cluster, or at cluster shutdown if the tracker was not unregistered.
void	setPercentileLatencyTracker(PercentileTracker percentileLatencyTracker) Set the percentile tracker to use for recording per-host latency histograms.
void	setSlowQueryLatencyThresholdPercentile(double slowQueryLatencyThresholdPercentile) Set the threshold percentile beyond which queries are considered 'slow' and logged as such by the driver.

Methods inherited from class com.datastax.driver.core.QueryLogger

append, append, appendParameters, appendParameters, builder, countBoundValues, getMaxLoggedParameters, getMaxParameterValueLength, getMaxQueryStringLength, logQuery, maybeLogErrorQuery, maybeLogNormalQuery, parameterValueAsString, parameterValueAsString, setMaxLoggedParameters, setMaxParameterValueLength, setMaxQueryStringLength, statementAsString, update

Methods inherited from class java.lang.Object

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

Method Detail

getPercentileLatencyTracker

public PercentileTracker getPercentileLatencyTracker()

Return the percentile tracker to use for recording per-host latency histograms. Cannot be null.

Returns:

the percentile tracker to use.

setPercentileLatencyTracker

public void setPercentileLatencyTracker(PercentileTracker percentileLatencyTracker)

Set the percentile tracker to use for recording per-host latency histograms. Cannot be null.

Parameters:

percentileLatencyTracker - the percentile tracker instance to use.

Throws:

IllegalArgumentException - if percentileLatencyTracker == null.

getSlowQueryLatencyThresholdPercentile

public double getSlowQueryLatencyThresholdPercentile()

Return the threshold percentile beyond which queries are considered 'slow' and logged as such by the driver. The default value is QueryLogger.DEFAULT_SLOW_QUERY_THRESHOLD_PERCENTILE.

Returns:

threshold percentile beyond which queries are considered 'slow' and logged as such by the driver.

setSlowQueryLatencyThresholdPercentile

public void setSlowQueryLatencyThresholdPercentile(double slowQueryLatencyThresholdPercentile)

Set the threshold percentile beyond which queries are considered 'slow' and logged as such by the driver.

Parameters:

slowQueryLatencyThresholdPercentile - Slow queries threshold percentile. It must be comprised between 0 inclusive and 100 exclusive.

Throws:

IllegalArgumentException - if slowQueryLatencyThresholdPercentile < 0 || slowQueryLatencyThresholdPercentile >= 100.

maybeLogNormalOrSlowQuery

protected void maybeLogNormalOrSlowQuery(Host host,
                                         Statement statement,
                                         long latencyMs)

Specified by:

maybeLogNormalOrSlowQuery in class QueryLogger

maybeLogSlowQuery

protected void maybeLogSlowQuery(Host host,
                                 Statement statement,
                                 long latencyMs,
                                 long threshold)

onRegister

public void onRegister(Cluster cluster)

Description copied from interface: LifecycleAwareLatencyTracker

Gets invoked when the tracker is registered with a cluster, or at cluster startup if the tracker was registered at initialization with Cluster.register(LatencyTracker).

Parameters:

cluster - the cluster that this tracker is registered with.

onUnregister

public void onUnregister(Cluster cluster)

Description copied from interface: LifecycleAwareLatencyTracker

Gets invoked when the tracker is unregistered from a cluster, or at cluster shutdown if the tracker was not unregistered.

Parameters:

cluster - the cluster that this tracker was registered with.