Apparently transient error cl5DBData2Entry - Invalid data version

[Roderick Johnstone]

Hi

We have 3 IPA servers which we are in the process of updating from RHEL 
7.7 to RHEL 7.8.

Servers X, Z are at: ipa-server-4.6.6-11.el7.x86_64 (RHEL 7.8)
Server W is at: ipa-server-4.6.5-11.el7_7.3.x86_64 (RHEL 7.7)

Server X was updated some time ago, and server Z was updated last Thursday.

I was doing some checks of the log files before our planned update of 
server W to RHEL 7.8 tomorrow and found the following in 
/var/log/dirsrv/slapd-REALM/errors:

[26/Apr/2020:22:00:21.704887592 +0100] - INFO - dblayer_copy_directory - 
Backing up file 119 
(/var/lib/dirsrv/slapd-REALM/bak/REALM/ipaca/vlv#cacompleterenewalpkitomcatindex.db)

[26/Apr/2020:22:00:23.627421118 +0100] - ERR - NSMMReplicationPlugin - 
changelog program - cl5DBData2Entry - Invalid data version

[26/Apr/2020:22:00:24.760704543 +0100] - INFO - dblayer_copyfile - 
Copying 
/var/lib/dirsrv/slapd-REALM/db/ipaca/vlv#cacompleterenewalpkitomcatindex.db 
to 
/var/lib/dirsrv/slapd-REALM/bak/REALM/ipaca/vlv#cacompleterenewalpkitomcatindex.db

[26/Apr/2020:22:00:24.776815976 +0100] - ERR - NSMMReplicationPlugin - 
changelog program - cl5DBData2Entry - Invalid data version

The errors were generated during our cronjob that runs this each night:
/sbin/ipa-backup --data --online

The errors don't seem to have been present the last two nights.

Would I be right to assume that this is just some transient 
inconsistency caused by doing the online backup or should I be more 
worried even though the error hasn't occurred since?

Thanks for any insights on this.

Roderick Johnstone