Re: Recovery bugs, classified by me

[Christopher Powers]

Philip Stoev wrote:
> It is OK however to re-triage this bug to a lower SR tag.
> 
>> http://bugs.mysql.com/bug.php?id=36993
>> Bug#39139 Falcon reports Index SCHEDULE..PRIMARY_KEY in SYSTEM.SCHEDULE
>> damaged
>> Suspected cause:
>> Kill -9 before system tables were completely created.
>> Suggested fix: won't fix (good workaround)
>> Workaround: delete all falcon spaces and serial logs.
> 
> Note that this is just an error printed in the log, the database 
> continues to run. Therefore "delete all falcon tablespaces" is not a 
> good workaround because a person may not even notice the problem, since 
> it does not reveal itself in a crash. God knows what else is also damaged.

Seems to me that if the system tables are not fully established, then 
the database is not viable and recovery should not be run.

> Also, the kill -9 did not happen while the server was starting up. The 
> server had already started and databases and tables were created by the 
> time the kill -9 arrived. Therefore, it is not about "killing before 
> system tables were completely created", it may be about "killing before 
> gophers applied all serial log events related to system tables".
> 
> So, this remains a valid bug for me. I do intend to test recovery 
> systematically with kill -9 immediately after server startup, so a 
> decision and a solution must be implemented for that one. Maybe the 
> solution is to do extra checkpoints after creating the system tables and 
> waiting for the gophers to write everything to disk.
> 
> Philip Stoev
>