It is the version of the KahaDB format on-disk. Did you perform the upgrade with previous data?
I suspect you saw 5.16.2 load previous files from 5.15.11 (version 6) and then create new files with version 7. 5.15.x version 6 ref: https://github.com/apache/activemq/blob/activemq-5.15.15/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java#L140 <https://github.com/apache/activemq/blob/activemq-5.15.15/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java#L140> 5.16.x version 7 ref: https://github.com/apache/activemq/blob/activemq-5.16.x/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java#L139 <https://github.com/apache/activemq/blob/activemq-5.16.x/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java#L139> -Matt Pavlovich > On May 26, 2021, at 4:21 PM, VenuGopal Thati <[email protected]> wrote: > > Hi, > > While upgrading from ActiveMQ version 5.15.11 to 5.16.2, there is a log > line that says KahaDB version is 6 but when I downgraded back to 5.15.11, > log line printed as KahaDB version is 7. Are these versions related to the > state of the database because of upgrades ? Or the actual KahaDB ? If it's > actual KahaDB, I am wondering why the version is going down in the new > version of ActiveMQ. > > I looked into the source code link below, it's reading this version value > from java.io.DataInput but I couldn't figure out whether it's the actual > database version. Thanks for your help. > > https://github.com/apache/activemq/blob/ccb1050af9d1ecd5dbd18c4d8df33fdf10cc84dd/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java#L179 > > > -- > Regards, > Venu.
