[Catalyst] MySQL server has gone away

[Jeff Chimene]

Oleg Pronin wrote:
> If you don't need transaction you don't use it. This is not we talking
> about. To use transaction or not in every case is a high-level logic
> decision
I disagree. That /is/ what we are talking about - unless MySQL cannot
tell you that the database connection has evaporated while in
transaction context. I don't know MySQL well enough in this instance to
say for certain that transaction context will address this issue. In a
well-designed RDBMS, a transaction will report "failure" if, while in
the context of a transaction, any statement fails. In that case, the
entire transaction which may consist of several prepare/execute
operations that can be rolled back and retried.

Transactions are /precisely/ the mechanism to determine, at a high
level, when a certain operation has failed.
>
> 2007/4/27, Jeff Chimene <jchimene at gmail.com <mailto:jchimene at gmail.com>>:
>
>     Oleg Pronin wrote:
>     > One can say that it is a very rare situation. I can tell you that in
>     > production environment (about 1.000.000 hits per day) it happens
>     every
>     > day several times. Some users just see an error, some lost their
>     data.
>     > This is just not always visible to you.
>     The OP may find a requirement to incorporate a transaction model
>     (explicit start txn/commit/rollback) to solve this problem in MySQL;
>     which is what they'd have to do for Oracle or Postgres or Rdb. I'd
>     hope
>     that MySQL reports a transaction failure when the database connection
>     evaporates. This would allow a retry on the failed transaction.
>     However,
>     it may be that the Catalyst Controller / View design/implementation is
>     only what would ordinarily be flat file accesses that use SQL
>     instead of
>     keyed-access flat files. If that's the case, wrapping a transaction
>     around each of these SQL prepare/execute pairs will be a substantial
>     performance hit.
>
>     _______________________________________________
>     List: Catalyst at lists.rawmode.org <mailto:Catalyst at lists.rawmode.org>
>     Listinfo: http://lists.rawmode.org/mailman/listinfo/catalyst
>     Searchable archive:
>     http://www.mail-archive.com/catalyst@lists.rawmode.org/
>     Dev site: http://dev.catalyst.perl.org/
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> List: Catalyst at lists.rawmode.org
> Listinfo: http://lists.rawmode.org/mailman/listinfo/catalyst
> Searchable archive: http://www.mail-archive.com/catalyst@lists.rawmode.org/
> Dev site: http://dev.catalyst.perl.org/
>