MetricFileNameComparator will throw ArrayIndexOutOfBoundsException when metric log dir has both pid and no-pid files

[wh88725]

Issue Description

Type: bug report

Describe what happened (or what feature you want)

MetricFileNameComparator will throw ArrayIndexOutOfBoundsException when metric log dir has both pid and no-pid files.
In MetricFileNameComparator.compare() method, when the first comparing filename has the "pid" tag, it also consider the second comparing filename has the pid tag. If the filename do not have, this will lead the ArrayIndexOutOfBoundsException

the file list:
org-codehaus-classworlds-Launcher-metrics.log.2019-08-26.14
org-codehaus-classworlds-Launcher-metrics.log.2019-08-26.15
org-codehaus-classworlds-Launcher-metrics.log.2019-08-26.16
org-codehaus-classworlds-Launcher-metrics.log.2019-08-27
org-codehaus-classworlds-Launcher-metrics.log.pid20760.2019-08-26
org-codehaus-classworlds-Launcher-metrics.log.pid6192.2019-08-26

the exception stack:
2019-08-27 11:42:57 write metric error:
java.lang.ArrayIndexOutOfBoundsException: 3
at com.alibaba.csp.sentinel.node.metric.MetricWriter$MetricFileNameComparator.compare(MetricWriter.java:250)
at com.alibaba.csp.sentinel.node.metric.MetricWriter$MetricFileNameComparator.compare(MetricWriter.java:238)
at java.util.TimSort.countRunAndMakeAscending(TimSort.java:355)
at java.util.TimSort.sort(TimSort.java:220)
at java.util.Arrays.sort(Arrays.java:1512)
at java.util.ArrayList.sort(ArrayList.java:1454)
at java.util.Collections.sort(Collections.java:175)
at com.alibaba.csp.sentinel.node.metric.MetricWriter.listMetricFiles(MetricWriter.java:292)
at com.alibaba.csp.sentinel.node.metric.MetricWriter.removeMoreFiles(MetricWriter.java:297)
at com.alibaba.csp.sentinel.node.metric.MetricWriter.closeAndNewFile(MetricWriter.java:312)
at com.alibaba.csp.sentinel.node.metric.MetricWriter.write(MetricWriter.java:136)
at com.alibaba.csp.sentinel.node.metric.MetricTimerListener.run(MetricTimerListener.java:58)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.runAndReset$$$capture(FutureTask.java:308)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

Describe what you expected to happen

MetricFileNameComparator.compare() mothed should cover this situation

How to reproduce it (as minimally and precisely as possible)

1. use -Dcsp.sentinel.log.use.pid=true to run a while to generate files contains pid
2. delete the property to run a while
3. the exception appear in sentinel-record.log

Tell us your environment

sentinel version: 1.3.0.GA
windows 7

Anything else we need to know?

[sczyh30]

Hi, is this reproducible with the latest 1.6.3 version?

[wh88725]

I didn't test it in 1.6.3. I just read the latest MetricFileNameComparator and it has no change.
if the latest version fix it in another way, i can try it.

[sczyh30]

This might have been fixed by #331. You have to ensure whether this bug can be reproduced in the latest version.

[wh88725]

OK. I will try it later.