Error Code -6 when applying a transaction log file (from live backup)

[justin_willey]

We are occasionally getting the undocumented error code -6 when applying a transaction log using dbsvr17.exe (v17.0.10.6175). The transaction log is generated by dbbackup.exe with the live log option from a database running elsewhere on a WAN.

The command line is:

dbsrv17 -n LogApply -o "/srv/iqx/backup/central/Messages/20210505194503 Live Backup Log Apply.txt" -qs -c 1G -ca 0 -x none -xd /srv/iqx/backup/central/IQX.db -a /srv/iqx/backup/central/SafeLive.log -ek ***

The error is:

I. 05/05 19:45:03. Database recovery in progress
I. 05/05 19:45:03.     Last checkpoint at Wed May 05 2021 11:30
I. 05/05 19:45:03.     Transaction log: /srv/iqx/backup/central/SafeLive.log...
I. 05/05 19:45:03.     Parallel recovery enabled
I. 05/05 19:45:09.     ... recovery 1% complete
******************** ERROR ********************
19:45:09 Failed with exit code -6

It seems that the log file has been corrupted somehow, because if the live backup transaction log file is deleted and dbbackup restarted, the new transaction log file created can then be applied without any problem. Only dbbackup and dbsrv17 are interacting with the live backup transaction log file.

dbtran.exe will translate the log file without error - suggesting that if there is a corruption, it must be very minor.

The situation here is that a live backup log file is being maintained by dbbackup and is being regularly applied to the stand-by database. We have seen this happen on a number of WANs but not on LANs, on both Windows & Linux.

Does the -6 error code give any indication of what the problem might be?

[Breck_Carter]

Is that message contained in the dbsrv17 -o txt file, or did it get appended by a command file or some such artifact?

...because the message format doesn't look like the others.

Auntie Google has no clue, "exit code -6" is strange, like bog snorkeling.

[justin_willey]

Hi Breck - you are right - its appended by the controlling (Python) program reporting the exit code from dbsrv17 that seems to have just bombed out.

[justin_willey]

"bog snorkeling" - extreme ironing is probably more fun

[Breck_Carter]

> exit code from dbsrv17

If the Python program added the minus sign, then 6 means communication failure according to the exit code list https://help.sap.com/viewer/98ad9ec940e2465695685d98e308dff5/17.0/en-US/3be2a6b66c5f10149c10fa0b095c...

I searched all the SA17 sdk*.h files and there's a -1 and -2, but they aren't error codes, and there is no -6.