[improve] add metrics: total_entry_log_space_bytes

[ethqunzhong]

Motivation

add metric TOTAL_ENTRY_LOG_SPACE_BYTES As a supplement to metric ACTIVE_ENTRY_LOG_SPACE_BYTES

This allows us to easily analyze the proportion of valid data in the cluster entry log.

Changes

1. add metric TOTAL_ENTRY_LOG_SPACE_BYTES in GarbageCollectorStats.
2. Standardize totalEntryLogSize and activeEntryLogSize naming.

[liangyepianzhou]

LGTM, It is also recommended to add a test

[StevenLuMT]

reopen's reason: rerun failure checks

[StevenLuMT]

LGTM

[hezhangjian]

I am a little hesitat, I prefer to remove TOTAL_ perfix, it's common appears as suffix to indicate it's type. Put it in front doesn't bring additional information.

[eolivelli]

+1

[eolivelli]

For the name: we sure follow current conventions in the project codebase

[hezhangjian]

@eolivelli I didn't see "TOTAL_" prefix in other metric name. did I miss something?

[StevenLuMT]

+1, It might be better to change total_entry_log_space_bytes to entry_log_space_bytes.

[ethqunzhong]

+1, It might be better to change total_entry_log_space_bytes to entry_log_space_bytes.

@StevenLuMT thx, make sense. updated.

[dlg99]

Please fix the checkstyle error. Otherwise LGTM.

[INFO] There is 1 error reported by Checkstyle 9.3 with buildtools/src/main/resources/bookkeeper/checkstyle.xml ruleset.
Error:  src/main/java/org/apache/bookkeeper/bookie/stats/GarbageCollectorStats.java:[38,1] (imports) ImportOrder: Import org.apache.bookkeeper.bookie.BookKeeperServerStats.ENTRY_LOG_SPACE_BYTES appears after other imports that it should precede

[StevenLuMT]

@ethqunzhong please fix it

[hezhangjian]

Thanks for your contribution. :)