Hmm.. I do not know enough about the SimpleLDAPObject code. Perhaps a 
python-ldap developer can provide more information (but I think they will 
recommend that you not use SimpleLDAPObject). Assigning to self may not work as 
you expect. I do not think you will be able to replace the SimpleLDAPObject 
inside an exception handler.

Creating a new LDAP connection using the same URIs as the original is valid 
logic, but your code will need to keep track of the state of pending LDAP 
requests and whether they have completed successfully, perhaps storing the 
requests in some sort of local database. The LDAP API itself does not provide 
for this sort of complex behavior. The level of redundancy you seek is not easy.

Yancey


On Mar 29, 2010, at 1:03 PM, Alberto Luengo Cabanillas (Pexego) wrote:

Yeargan, Yancey wrote:

I think it is as simple as using multiple URL values separated with spaces. For 
example:

ldap.initalize("url1 url2 url3")

The underlying LDAP code will automatically try each URL until one succeeds or 
they all fail.

Yancey

Hi Yeargan. Thanks for the quick reply but that's not exactly the problem we're 
facing. The point that if you initialize url1, url2 and url3, with url1 down, 
the followup queries will be against url2. That's a correct behaviour, but if 
while you're keeping up that connection, this url2 server goes down, you'll get 
an exception, instead of trying to reconnect to next available server (url1 or 
url3), supposing, of course, that they have an equivalent structure.
So, when this happens, we're initializing another LDAPObject with remaining 
URIs this way:

new_object =  ldap.functions._ldap_function_call(_ldap.initialize,string_uris)

self = new_object (or self._l = new_object?)

, but this still fails, any suggestion?

Greetings.


On Mar 29, 2010, at 9:41 AM, Alberto Luengo Cabanillas (Pexego) wrote:

Hi all! Me and a workmate are currently working in an approach of connecting to 
different LDAP servers (each one is a replica of another) because of fault 
tolerancy purposes.
So, first thing we did was modifying the __init__ method of SimpleLDAPObject 
class (ldapobject.py file) adding a new attribute "pool" which contains the 
list  of servers passed as param in initialize method as a string. So, 
attribute ._l changes to:
    self._l = ldap.functions._ldap_function_call(_ldap.initialize,self._pool[0])

Then, in _ldap_call we introduced a while loop surrounding all code with a 
boolean condition set to False. When "func" call fails raising a "SERVER_DOWN" 
exception, we remove URI from pool and create a new ReconnectLDAPObject 
instance with self._l attribute pointing to next LDAP URI in pool.

The problem we're actually facing is that when func calls raises a SERVER_DOWN 
exception (with, for example, a search_s operation) the code behaviour is 
correct when URI is wrong, but when LDAP URI is right the func calls stills 
raises an exception...Is this because of what is explained in the beginning of 
ReconnectLDAPObject class (that synchronous methods like search_s() 
automatically tries to reconnect when LDAP server is down)?.

Are we pointing in the right direction?

Thanks a lot in advance.
<ATT00001..c><ATT00002..c>



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