Re: BUG #15182: Canceling authentication due to timeout aka Denial ofService Attack - Mailing list pgsql-hackers

From Bossart, Nathan
Subject Re: BUG #15182: Canceling authentication due to timeout aka Denial ofService Attack
Date
Msg-id 082C3D70-C39D-41F4-B889-C128D09DE02E@amazon.com
Whole thread Raw
In response to Re: BUG #15182: Canceling authentication due to timeout aka Denial ofService Attack  ("Bossart, Nathan" <bossartn@amazon.com>)
List pgsql-hackers
On 7/26/18, 10:07 AM, "Bossart, Nathan" <bossartn@amazon.com> wrote:
> The first time we use this callback, the relation won't be locked, so
> isn't it possible that we won't get a valid tuple here?  I did notice
> that callbacks like RangeVarCallbackForRenameRule,
> RangeVarCallbackForPolicy, and RangeVarCallbackForRenameTrigger assume
> that the relation can be concurrently dropped, but
> RangeVarCallbackOwnsRelation does not.  Instead, we assume that the
> syscache search will succeed if the given OID is valid.  Is this a
> bug, or am I missing something?

Please pardon the noise.  I see that we don't accept invalidation
messages until later on in RangeVarGetRelidExtended(), at which point
we'll retry and get InvalidOid for concurrently dropped relations.

Nathan


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