KB-1419 Negative KDB numbering
Symptom
KDB file numbering for one or more engines moves into the negatives. This may manifest in:
- the names of actual .kdb files on disk
- the checkpointing messages in the corresponding gw_*.log
- the DB ID referenced in the corresponding db_*.log
For example, if the process execution01 engine is the one in question, you may notice the following:
- A negative .kdb file in
<APPIAN_HOME>/server/process/exec/01/gw1/: pe-2147483646.kdb. - A reference in the gw_PX001*.log:
[PX001] INFO .a.gw.ssa "Server switchover to database ID -2147483646". - A reference in the db_PX001*.log:
[PX001] {pe-2147483646.kdb ,4405}.
Cause
This issue can occur after improperly resetting a particular engine's KDBs or if extraneous KDB files are manually introduced.
Action
- Shut down the engine with the negative KDB numbering.
- Rename any negative KDBs to positive numbers, ensuring that the most recent KDB has the highest number.
- Check that all KDB file names look normal - i.e. no remaining negative numbers or manually introduced KDBs such as pe.kdb.
- Start the engine and confirm that KDB numbering is positive once again.
Warning: Renaming .kdb files is not supported beyond what is documented in Appian documentation, the Appian Playbook, and KB articles.
Affected Versions
This article applies to all self-managed versions of Appian.
Last Reviewed: November 2017