[R-sig-DB] RMySQL doesn't auto-reconnect

[Jack Tanner]

Unfortunately, the server in question is on a web host, so I almost 
certainly have no control of time-out parameters, even just to play with 
to test the hypothesis. The loss of connection usually happens within 
seconds, not even tens of seconds. Connecting from a different client 
machine still results in "server has gone away."

I agree that auto-reconnect is a kludge, but I don't really know how to 
diagnose the failure of the connection. Ideas welcome. :)

Could you clarify why auto-reconnect is dangerous security-wise?

Paul Gilbert wrote:
> Jack
>
> It is possible this is a firewall, but I think there is also a 
> connection timeout parameter on the server, which can be adjusted. I'm 
> not sure what the default is, but I don't usually have trouble unless 
> I leave a connection sitting idle overnight. Probably the firewall has 
> some sort of connection timeout too. I think both these timeouts 
> should depend on idle time, so are not consistent with the problem you 
> report.
>
> Auto-reconnect would fix your problem, but I don't think you should be 
> getting dropped in the first place, unless you are really leaving the 
> connection idle for a long time.  If you are doing that, I would not 
> recommend auto-reconnect  (for security reasons).
>
> Paul
>
> Jeffrey Horner wrote:
>> Jack Tanner wrote:
>>
>>> After I do library(RMySQL), dbConnect(), and run a few queries, I 
>>> sometimes get this:
>>>
>>> Error in mysqlExecStatement(conn, statement, ...) :
>>>  RS-DBI driver: (could not run statement: MySQL server has gone away)
>>>
>>> If I issue a dbConnect() again, I can run queries again ... for a 
>>> little while, and then I get another "server has gone away".
>>>
>>> The MySQL server is on a separate machine from the client. It's 
>>> entirely possible that there's one or more firewalls in between, 
>>> which could be causing the problem. The
>>>
>>> I understand that MySQL has auto-reconnect functionality:
>>>
>>> http://blog.taragana.com/index.php/archive/how-to-enable-disable-auto-reconnect-in-mysql/ 
>>>
>>>
>>> Does RMySQL allow me to turn on auto-reconnect? If so, how?
>>
>>
>> Unfortunately it doesn't right now, but that would be a great 
>> addition. I've often had to test for the connection going away for 
>> unknown reasons as well.
>>
>> I'll pencil it in for the next release as it's easy to add.
>>
>> Jeff
>>
>>>
>>> > version
>>>               _                          platform       
>>> i386-redhat-linux-gnu      arch           i386                       
>>> os             linux-gnu                  system         i386, 
>>> linux-gnu            status                                    
>>> major          2                          minor          
>>> 9.1                        year           2009                       
>>> month          06                         day            
>>> 26                         svn rev        48839                      
>>> language       R                          version.string R version 
>>> 2.9.1 (2009-06-26)
>>> > mysqlClientLibraryVersions()
>>> 5.0.45 5.0.45
>>> 50045  50045