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From:Philip Stoev Date:April 9 2009 8:45am
Subject:Re: Recovery bugs, classified by me
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>> 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.
>
> And what you do if you kill before checkpoint has run?

It appears to me that the current behavior is as follows:

1. Falcon starts up, system tables are created in memory
2. Server becomes available for connections
3. Queries start arriving
4. A scheduled checkpoint arrives, the gophers write the system tables to 
disk, etc.

If there is a crash in Step #3, you can not use a workaround "delete 
tablespaces and start from scratch", because you would loose the 
transactions that were issued by the users.

So, instead, maybe this will work:

1. Falcon starts up
2. System tables are created and flushed to disk, force two checkpoints, 
waits for gophers to complete, whatever is needed
3. Server becomes available for connections
4. Queries start arriving

This way, for crashes in Step #2, the workaround can be "delete tablespaces 
and start from scratch". Crashes in Step #4 should recover properly without 
waivers.

Philip Stoev 

Thread
Blobs, earlyWrite, and All ThatJim Starkey9 Apr
  • Recovery bugs, classified by meVladislav Vaintroub9 Apr
    • PAGE IO bugs, classified by meVladislav Vaintroub9 Apr
    • Recovery and Page IO bugs classified by VladChristopher Powers11 Apr
  • Re: Recovery bugs, classified by mePhilip Stoev9 Apr
    • RE: Recovery bugs, classified by meVladislav Vaintroub9 Apr
      • Re: Recovery bugs, classified by meJames Day13 Apr
        • Re: Recovery bugs, classified by meKevin Lewis13 Apr
    • RE: Recovery bugs, classified by meVladislav Vaintroub9 Apr
    • Re: Recovery bugs, classified by meChristopher Powers11 Apr
      • Re: Recovery bugs, classified by meJames Day13 Apr
  • Re: Recovery bugs, classified by mePhilip Stoev9 Apr
    • RE: Recovery bugs, classified by meVladislav Vaintroub9 Apr
  • Re: Recovery bugs, classified by mePhilip Stoev9 Apr
  • Re: Recovery bugs, classified by mePhilip Stoev11 Apr