Kbase 17815: SYSTEM ERROR: Unrecognized undo code <15>. (5310)
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
7/22/1998 |
|
SYSTEM ERROR: Unrecognized undo code <15>. (5310)
SYSTEM ERROR: Unrecognized undo code <15>. (5310)
This error has shown up several times over the last few years, yet a
reproducible case and a plausible explanation have both eluded us.
This knowledgebase article will attemt to explain what is causing the
error internally and what steps to take in troubleshooting it.
This error comes while we are trying to back out a transaction.
This process is called LOGICAL UNDO, and it is performed by the undo
dispatcher. During this processing each bi log record generated by the
transaction is being read from the newest to oldest and we are
performing the operation that is the opposite of the operation
recorded in the corresponding bi log record. A good example of this
would be recreating a record that has just been deleted.
This processing continues to read all of the bi log records backwards
sequentially until we get to the beginning of the transaction, which
is marked by the the transaction BEGIN record.
When we see the SYSTEM ERROR: Unrecognized undo code <15>. (5310), the
15 in this case indicates that the undo dispatcher encountered a
transaction END record when it was expecting the BEGIN record, and
this obviously should never happen. Either the transaction begin
record was skipped over, or it is missing, and we have reached the end
of the previous transaction. These are just some possibilities, and
nothing has been proven up to this point, however this IS indicative
of a Progress bug.
Some other possibilities are that a bug is causing the bi cluster to
be reused by mistake, even though the transaction was still active
and now its notes are gone. Another could be that the starting bi
address for this transaction has been smashed, or this could be a
symptom of hitting the 2gig file size limitation for the bi file.
We have no evidence to support these theories, however they are simply
some ideas Development has come up with based on the bi file's
architecture.
Although most of this is theory, we do have a bug logged on this
issue: 98-03-19-022. This is not reproducible and does not appear at
this time to be limited to a particular version or platform. We
require a reproducible case to add to the bug, and should even try to
get a copy of the database receiving the error in house to duplicate
the problem. This error should be treated as BI CORRUPTION with the
advice of either forcing in and dumping and loading, or to restore
a backup copy of the database. As always, there is no way to find out
at this point exactly how much corruption if any has been written to
the database.
SDA 3/31/98
Progress Software Technical Support Note # 17815