Forum OpenACS Development: Re: Get number of visitors currently browsing the site

In my experience uniqueness of the ip address is very unreliable. There are providers where all accesses appear to come from the same ip address, others where the address of a single user changes from request to request. I wouldn't use it it for anything besides vague estimates.

I guess that the problem with session_id is that it will also count the spiders, etc (I mean, everything accessing the site).

Something like:

set ten_min_ago [expr [ns_time] - (10*60)]
set sql_query "select count(distinct session_id) 
    as result from sec_session_properties where last_hit > :ten_min_ago"
db_1row select_sessions $sql_query

should give you some sessions. The only issue that I see is that, at least in OpenACS 4.6.3 (that's what we are using at the moment) you don't have an index on sec_session_properties(last_hit) so this query is quite inefficient (but I am not sure than adding an index is also a good solution, this table is touched a lot -for every hit, right?-).

Just my 2 cents,

/B

I tried Bruno's query and find that I get 0 sessions even if there is an active member session.