Oops, sorry: link to sources http://www.bernardlebel.com/scripts/nonxsi/help/
Thanks again Bernard On 1/18/06, Bernard Lebel <[EMAIL PROTECTED]> wrote: > Hello, > > I'm stumbled at a serious problem, and quite frankly getting > desparate. This is a rather long-winded one so I'll try to get > straight to the point. > > I have this Python program, that performs MySQL queries to a database. > These queries are performed at regular intervals. Basically it is > looking for fields that match certain criterias. Such fields are not > present at all time. When the program finds such field, it then takes > an action, if nothing is found, just keep this query-fetch cycle > forever. > > I don't know where the source of the problem is, but the symptoms go as > follow: > > When the program starts, the first time it performs a certain > query/fetch, a result is fetched. Now, later on, when the action done > after the first fetched is completed, the program starts > querying/fetching again. But it seems unable to the fetch anything > else with the same query. > > If an entry that the query should return is inserted in the database, > the program just can't get it once it has started. > > A more schematic representation of the symptoms. > > What it should do: > 1. program starts > 2. enter query-fetch cycle > 3. find specific entry, take action > 4. action done > 5. resume query-fetch cycle > 6. find specific entry, take action > 7. action done > 8. resume query-fetch cyle > 9. there was nothing to be found, continue cycle > 10. find specific entry, take action > 11. action done > 12. resume query-fetch cycle........... > > What it does now: > 1. program starts > 2. enter query-fetch cycle > 3. find specific entry, take action > 4. action done > 5. resume query-fetch cycle > 6. no more entry fetched despite valid entries being in the database > > What is does now also: > 1. program starts > 2. enter query-fetch cycle > 3. there was nothing to be found, continue cycle > 4. valid entry added my myself, manually, and successfully committed > 5. query-cycle continues, entry just added never found....... > > I have looked at connection objects, cursor objects, and I just can't > seem to find the cause of that behavior. > > In parallel, if I run individual queries in a command line shell, I > fetch the entries as expected. > The only way I have found to force the program to find the new entry, > is to close the connection and create a new one, every time it > performs a transaction. Not very efficient. > > > > To give a little more details about the implementation.... when the > program starts, it starts a little queue server in a separate thread. > This queue server is nothing more than a list. Each time a query has > to be performed, it is added to the queue. > The queue server checks the queue to find if it has something to do. > > When if finds something, it carries the entire operation, from query > to fetch/commit. It then stores the result in a dictionary, using a > unique ID as the key. At that point, the list element is removed from > it. > > The function that submitted the query to the queue, during that times, > checks the dictionary until the result of the operation shows up, and > then checks the actual result. The result is then returned to the > original function who submitted a database transaction. > > > > I don't know what other details to provide, other than the sources > themselves....... > farmclient_2.0_beta05.py is the top program file > The other py files are the imported modules > - fcSql is the actual database transaction management module > - fcJob has a function called readyGetJob(), wich is at the origin of > the MySQL query. The actual query being used is located on line 202. > The sql file is used to create the database > > Thanks for any help, let me know if you need more details > > Bernard > -- http://mail.python.org/mailman/listinfo/python-list
