[Vtigercrm-developers] Duplicate CRMIDs 5.40

[Joe Bordes]

I agree, I had noticed this also although we haven't run into the 
problem either (at least that we know of).

+1

On 08/01/14 13:48, Zygmuntowicz Michal wrote:
> I did not hit this problem (or maybe I just did not notice it), but 
> recently I took a look
> at the adodb library GenID function that creates unique IDs 
> for sequences and for me it seems
> that this function may not be safe under some circumstances.
> Most objects use the singleton instance of the global $adb 
> PearDatabase object.
> 1. The genID function of the underlaying adodb object is not thread 
> safe, as it uses
>    $this->genID to store intermediate result and return it upon 
> function exit.
>    But this should not be an issue, as script execution is 
> single-threaded and each
>    HTTP request will get its own $adb object.
> 2. The genID function is using last_insert_id, which works only if the 
> database connection
>     is used only by a single script and single thread. I don't know 
> what happens
>     if the web server uses connection pooling. Maybe it is possible 
> that the same database
>     connection is shared between concurrent HTTP requests and 
> therefore last_insert_id
>     may return incorrect values.
> 3. I am not sure if the sequence tables should be locked - I guess 
> autoincrement columns
>     should be transaction safe.
> These are only my thoughts - I think someone with good understanding 
> of the web server/mysql/php
> interactions should throw some light on this.
>
> *From:* Stefan Warnat <mailto:ich at stefanwarnat.de>
> *Sent:* Wednesday, January 08, 2014 12:05 PM
> *To:* vtigercrm-developers at lists.vtigercrm.com 
> <mailto:vtigercrm-developers at lists.vtigercrm.com>
> *Subject:* [Vtigercrm-developers] Duplicate CRMIDs 5.40
>
> Hy,
>
> Yesterday I found a very strange situation in one of my clients vtiger 
> 5.4 systems.
> The System ~250k records contains Leads with a leadid, which isn't a 
> "setype LEAD" in vtiger_crmentity.
> Some are Contacts, other Accounts, Tickets, ...
> Also the ID exist correctly in the respective tables of contacts, 
> accounts, ...
>
> I create the following problem situation:
> Two records are created in absolutely the same moment. (The 
> createdtime column is completely equal)
> Because ADODB don't lock the sequence table, there could be a chance 
> of duplicate crmid's, I suspect.
> I'm not fully sure how safe the used "LAST_INSERT_ID(id+1)" is.
> The normal "LAST_INSERT_ID()" is per connection, but only get back a 
> auto increment.
>
> Anyone other with this problem?
>
> Stefan
>
> ------------------------------------------------------------------------
> _______________________________________________
> http://www.vtiger.com/
>
>
> _______________________________________________
> http://www.vtiger.com/


-- 
Un saludo
Joe
TSolucio

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.vtigercrm.com/pipermail/vtigercrm-developers/attachments/20140108/0f2e8da5/attachment.html>