net.ttddyy.dsproxy.listener

Class SlowQueryListener

java.lang.Object

net.ttddyy.dsproxy.listener.SlowQueryListener

All Implemented Interfaces:

QueryExecutionListener

Direct Known Subclasses:

AbstractSlowQueryLoggingListener

public class SlowQueryListener
extends Object
implements QueryExecutionListener

Slow query detection listener. When query takes more than specified threshold, onSlowQuery(ExecutionInfo, List, long) callback method is called. The callback is called only once for the target query if it exceeds the threshold time. NOTE: ExecutionInfo.elapsedTime contains the time when callback is triggered which usually is the specified threshold time. If you want to log or do something with AFTER execution that has exceeded specified threshold time, use normal logging listener like following:

 
 long thresholdInMills = ...
 SLF4JQueryLoggingListener listener = new SLF4JQueryLoggingListener(){
       @Override
      public void afterQuery(ExecutionInfo execInfo, List queryInfoList) {
          if (execInfo.getElapsedTime() >= thresholdInMills) {
              super.afterQuery(execInfo, queryInfoList);
          }
      }
 };
 
 

Since:

1.4.1

Author:

Tadaya Tsuyukubo

See Also:

CommonsSlowQueryListener, JULSlowQueryListener, SLF4JSlowQueryListener, SystemOutSlowQueryListener

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	SlowQueryListener.RunningQueryContext Data holder for currently running query.

Field Summary

Fields

Modifier and Type	Field and Description
protected ScheduledExecutorService	executor
protected Map<String,SlowQueryListener.RunningQueryContext>	inExecution
protected long	threshold
protected TimeUnit	thresholdTimeUnit
protected boolean	useDaemonThread

Fields inherited from interface net.ttddyy.dsproxy.listener.QueryExecutionListener

DEFAULT

Constructor Summary

Constructors

Constructor and Description
SlowQueryListener()

Method Summary

Modifier and Type	Method and Description
void	afterQuery(ExecutionInfo execInfo, List<QueryInfo> queryInfoList)
void	beforeQuery(ExecutionInfo execInfo, List<QueryInfo> queryInfoList)
protected String	getExecutionInfoKey(ExecutionInfo executionInfo) Calculate a key for given ExecutionInfo.
ScheduledExecutorService	getExecutor()
long	getThreshold()
TimeUnit	getThresholdTimeUnit()
protected void	onSlowQuery(ExecutionInfo execInfo, List<QueryInfo> queryInfoList, long startTimeInMills) Callback when query execution time exceeds the threshold.
void	setThreshold(long threshHold)
void	setThresholdTimeUnit(TimeUnit thresholdTimeUnit)
void	setUseDaemonThread(boolean useDaemonThread) When set to true(default), the executor creates daemon threads to check slow queries.

Methods inherited from class java.lang.Object

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

Field Detail

useDaemonThread

protected boolean useDaemonThread

executor

protected ScheduledExecutorService executor

threshold

protected long threshold

thresholdTimeUnit

protected TimeUnit thresholdTimeUnit

inExecution

protected Map<String,SlowQueryListener.RunningQueryContext> inExecution

Constructor Detail

SlowQueryListener

public SlowQueryListener()

Method Detail

beforeQuery

public void beforeQuery(ExecutionInfo execInfo,
                        List<QueryInfo> queryInfoList)

Specified by:

beforeQuery in interface QueryExecutionListener

afterQuery

public void afterQuery(ExecutionInfo execInfo,
                       List<QueryInfo> queryInfoList)

Specified by:

afterQuery in interface QueryExecutionListener

getExecutionInfoKey

protected String getExecutionInfoKey(ExecutionInfo executionInfo)

Calculate a key for given ExecutionInfo.

This key is passed to the slow query check Runnable as well as for removal in afterQuery(ExecutionInfo, List).

Default implementation uses System.identityHashCode(Object). This does NOT guarantee 100% of uniqueness; however, since the current usage of the key is short lived and good enough for this use case.

Subclass can override this method to provide different implementation to uniquely represent ExecutionInfo.

Parameters:

executionInfo - execution info

Returns:

key

onSlowQuery

protected void onSlowQuery(ExecutionInfo execInfo,
                           List<QueryInfo> queryInfoList,
                           long startTimeInMills)

Callback when query execution time exceeds the threshold. This callback is called only once per query if it exceeds the threshold time.

Parameters:

execInfo - query execution info

queryInfoList - query parameter info

startTimeInMills - time in mills when the query started

setThreshold

public void setThreshold(long threshHold)

setThresholdTimeUnit

public void setThresholdTimeUnit(TimeUnit thresholdTimeUnit)

getExecutor

public ScheduledExecutorService getExecutor()

getThreshold

public long getThreshold()

getThresholdTimeUnit

public TimeUnit getThresholdTimeUnit()

setUseDaemonThread

public void setUseDaemonThread(boolean useDaemonThread)

When set to true(default), the executor creates daemon threads to check slow queries.

Parameters:

useDaemonThread - use daemon thread or not. (default is true)

Since:

1.4.2