Additional file being created when using with Multi-kahadb

[choudhary001]

When running these jars with MultiKahadb directory they create a db-1.log file. What is the purpose of this file ? I see that it is empty.

? ll -h db-1.log
-rw-r--r-- 1 choudhab choudhab 0 Jun 12 06:12 db-1.log


[06/12/18  6:12AM] choudhab at argon38.psc(nyc) in /u/choudhab/activemq/kahadb
? java -jar ~/Downloads/kahadb_tool/KahaDBJournalsStatistics.jar . 
 INFO | ignoring zero length, partially initialised journal data file: db-1.log number = 1 , length = 0
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 INFO | ignoring zero length, partially initialised journal data file: db-1.log number = 1 , length = 0
....
Rest of the output
...

[phamlankt]

I am not a developer. Could you please show me how you built the .jar file? Thanks.