Hi,
As co-contributor of the latest piece of code about SSS/VLV, I will try and give some explanations : VLV does not give a clean way to destroy the server side sorted entries list.
The SSS/VLV overlay implementation is using a limit in order to manage memory limits : a connection will be limited to a specified number of paged searches. The only way to reset this limit is to close and reopen a connection.
Maybe a timeout will be a good idea also but this is not implemented now.
Regards,
2011/7/1 Chris Card ctcard@hotmail.com
When using the sssvlv overlay how does the client tell the server
that the
sort request can be thrown away, so that sort requests don't hang
around until
sssvlv-max or sssvlv-maxpercon are exceeded?
There is no official mechanism for this. This is a flaw in the
Sorting/VLV
specification. For Paged Results you simply send a followup request
with
pagesize set to zero, but that doesn't apply for VLV.
I believe in our current implementation, if you send a new Paged
Results
request on a connection that has VLVs outstanding, one of the VLVs
will be
aborted. Unfortunately, if you have multiple VLVs outstanding, there's
no way
to determine which one gets aborted. (Apparently this was overlooked
when
patching the overlay to allow multiple VLVs on a connection...)
Thanks for the info. Is it the case that sort requests are associated with a particular
connection?
What does RFC2891 say?
As far as I can see it doesn't mention connections.
However, looking at the code in sssvlv.c, it appears that a sort operation is associated with a session, and a session is associated with a connection, e.g. on line 900 of sssvlv.c in sssvlv_op_search():
sort_conns[op->o_conn->c_conn_idx][sess_id] = so;From my testing it seems that a sort request will remain active in the
server evenif the client disconnects, which doesn't seem right.
How are you determining that this is the case?
I'm using ldapsearch to test requests with sss and vlv controls. After running several such ldapsearch commands I get an error from the server :
# search result search: 2 result: 51 Server is busy text: Other sort requests already in progress
I am assuming that the connection to the server is dropped when the ldapsearch command terminates; that must certainly be the case at the client end since the process no longer exists.
Chris