Reduce time to convert TaskFinishedEvent to string

"Dispatcher thread {Central}" #38 prio=5 os_prio=0 tid=0x00002ba188535800 nid=0x1b3e3 runnable [0x00002ba1a3e02000]
   java.lang.Thread.State: RUNNABLE
        at java.util.Arrays.copyOf(Arrays.java:3332)
        at java.lang.AbstractStringBuilder.ensureCapacityInternal(AbstractStringBuilder.java:124)
        at java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:448)
        at java.lang.StringBuilder.append(StringBuilder.java:136)
        at org.apache.tez.common.counters.AbstractCounters.toString(AbstractCounters.java:344)
        - locked <0x00000007a2ed6b80> (a org.apache.tez.common.counters.TezCounters)
        at org.apache.tez.dag.history.events.TaskFinishedEvent.toString(TaskFinishedEvent.java:135)
        at org.apache.tez.dag.history.HistoryEventHandler.handleCriticalEvent(HistoryEventHandler.java:155)
        at org.apache.tez.dag.history.HistoryEventHandler.handle(HistoryEventHandler.java:259)
        at org.apache.tez.dag.app.dag.impl.TaskImpl.logJobHistoryTaskFinishedEvent(TaskImpl.java:923)
        at org.apache.tez.dag.app.dag.impl.TaskImpl$AttemptSucceededTransition.transition(TaskImpl.java:1116)
        at org.apache.tez.dag.app.dag.impl.TaskImpl$AttemptSucceededTransition.transition(TaskImpl.java:1036)
        at org.apache.hadoop.yarn.state.StateMachineFactory$MultipleInternalArc.doTransition(StateMachineFactory.java:385)
        at org.apache.hadoop.yarn.state.StateMachineFactory.doTransition(StateMachineFactory.java:302)
        at org.apache.hadoop.yarn.state.StateMachineFactory.access$300(StateMachineFactory.java:46)
        at org.apache.hadoop.yarn.state.StateMachineFactory$InternalStateMachine.doTransition(StateMachineFactory.java:448)
        - locked <0x0000000717ed2120> (a org.apache.hadoop.yarn.state.StateMachineFactory$InternalStateMachine)
        at org.apache.tez.state.StateMachineTez.doTransition(StateMachineTez.java:59)
        at org.apache.tez.dag.app.dag.impl.TaskImpl.handle(TaskImpl.java:826)
        at org.apache.tez.dag.app.dag.impl.TaskImpl.handle(TaskImpl.java:112)
        at org.apache.tez.dag.app.DAGAppMaster$TaskEventDispatcher.handle(DAGAppMaster.java:2312)
        at org.apache.tez.dag.app.DAGAppMaster$TaskEventDispatcher.handle(DAGAppMaster.java:2299)
        at org.apache.tez.common.AsyncDispatcher.dispatch(AsyncDispatcher.java:180)
        at org.apache.tez.common.AsyncDispatcher$1.run(AsyncDispatcher.java:115)
        at java.lang.Thread.run(Thread.java:745)