If slow query log size larger than 64M,log file roll over failed

[yanhuqing666]

• dble version：2.18.09.0-release
• preconditions ：
  no
• configs：

schema.xml

~

rule.xml

~

server.xml

<property name="enableSlowLog ">1</property>
<property name="flushSlowLogPeriod ">1</property>
<property name="flushSlowLogSize ">1000</property>
<property name="sqlSlowTime ">10</property>

• steps：
  step1. If slow query log size large than 64M
• expect result：
  1. file roll over to new log file
• real result：
  1. file roll over failed,left lots of empty slow log files,and stackoverflow in wrapper.log

Exception in thread "SlowQueryLogProcessor" 
INFO   | jvm 1    | 2018/10/09 10:43:13 | java.lang.StackOverflowError
INFO   | jvm 1    | 2018/10/09 10:43:13 | 	at java.io.RandomAccessFile.open0(Native Method)
INFO   | jvm 1    | 2018/10/09 10:43:13 | 	at java.io.RandomAccessFile.open(RandomAccessFile.java:316)
INFO   | jvm 1    | 2018/10/09 10:43:13 | 	at java.io.RandomAccessFile.<init>(RandomAccessFile.java:243)
INFO   | jvm 1    | 2018/10/09 10:43:13 | 	at java.io.RandomAccessFile.<init>(RandomAccessFile.java:124)
INFO   | jvm 1    | 2018/10/09 10:43:13 | 	at com.actiontech.dble.log.DailyRotateLogStore.indexRollOver(DailyRotateLogStore.java:154)
INFO   | jvm 1    | 2018/10/09 10:43:13 | 	at com.actiontech.dble.log.DailyRotateLogStore.write(DailyRotateLogStore.java:111)
INFO   | jvm 1    | 2018/10/09 10:43:13 | 	at com.actiontech.dble.log.DailyRotateLogStore.writeFileHeader(DailyRotateLogStore.java:189)
INFO   | jvm 1    | 2018/10/09 10:43:13 | 	at com.actiontech.dble.log.DailyRotateLogStore.indexRollOver(DailyRotateLogStore.java:155)
INFO   | jvm 1    | 2018/10/09 10:43:13 | 	at com.actiontech.dble.log.DailyRotateLogStore.write(DailyRotateLogStore.java:111)

/label ~BUG

[yexiaoli88]

verified on version: 5.6.29-dble-2.18.10.0-6367e10-20181012031734