Re: [Cppcms-users] C++DB + MySQL disconnect

For anyone else who might care: This weekend I chased this back to the
MySQL backend. The MySQL client library loses all "prepared" queries when
the connection drops and they aren't made again when its auto-reconnected.
The C++DB backend thinks the query is still there and tries to re-use it
causing the "disconnect" error to act as if its being cached. I'll have to
fix this.

-Jon


On 03/25/2021 10:43 AM, Jon Foster wrote:
> This isn't specifically a C++CMS query. I'm using C++DB with C++CMS and
> FLTK to query a MariaDB server. With other languages and tools I can tell
> the client library to auto-reconnect and it does. From the C++DB docs I
> should be able to append ";opt_reconnect=1" to the connection string and it
> should auto-reconnect. But this has not been reliable, where in other tools
> it is. My test FLTK app, which doesn't use a connection pool, will fail
> after the idle timeout set in the server (1hr in this case) and *never*
> reconnect. My C++CMS apps which use connection pooling kind of work but I
> still get random 500s and logs telling me "MySQL went away". Fortunately it
> seems to mostly re-connect if I hit another page and then come back to the
> one that broke.
>
> But I *HATE* random fails in my projects. I'm not a "80% of the time it
> works 100% of the time" kind of guy. So! Is there an easy fix for this? Am
> I misinterpreting the docs and writing that option wrong? Or do I just need
> to dig into the source and force that client option? I'm not even sure why
> its an option. ;-) Anyhow I can't go live with a real C++CMS website and
> have this happening.
>
> Versions:
>
> C++DB: 0.3.1
> MariaDB: 10.0.38 & 10.2.25
> G++: 4.9.2
>
> TIA,
> Jon
>
>

-- 
Sent from my Devuan Linux workstation -- https://devuan.org/
"Init Freedom", Yeah!

Jon Foster
JF Possibilities, Inc.
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