Hi Bill, On 2/28/2014 11:28 AM, Ingram, William A wrote: > Hi Tim, > > This is DSpace 3.2, XMLUI. The slowness seems to occur on every page, but > ONLY when the user is logged in. That makes sense given the eperson and > epersongroup queries, which couldn't run otherwise. > We will give http://www.yourkit.com/ a try and report back if we get > anywhere. I haven't done enough detailed analysis of the queries. But at > first blush, it looks like DSpace is gathering all the groups the eperson is > a member of (ditto all the parent groups) and then running another query for > every other eperson in each of those groups. Since we have eperson groups > based on AD groups, some of these can be very large (e.g., "Students"). You > can see how this could be a problem if the system was running a database > query for every eperson from every group the logged-in user is a member of. > But like I said, I'm not a hundred percent sure that is even what's happening. > To be continued....
Actually, AD groups shouldn't be a problem. These types of external groups are "Special Groups" within DSpace. Essentially in DSpace, they have no members. But, when you login, a query is performed against AD or LDAP which then determines which of these Special Groups you are a member of. Then you are added to those DSpace groups *only for the remainder of your session*. IIRC, what is essentially supposed to happen is this... (1) You login, your EPerson info is queried in the database and is cached in the Session's Context object, as the "currentUser" https://github.com/DSpace/DSpace/blob/master/dspace-api/src/main/java/org/dspace/core/Context.java (2) Any Special Groups you are found to be a member of (by querying external AD or LDAP or similar) are also cached in the Context object (as the "specialGroups" list) (3) When any Group objects are loaded (by a database query), those Group objects are also cached in the Context Object (using cache() and fromCache()). The odd thing here is that, based on what you've said/provided, it sounds like #3 is not happening properly (since every page seems to rebuild those Group objects by re-querying the database). It's possible there's an odd bug here that is not readily apparent. I'm hoping maybe YourKit can give us some more clues as to what could be going on. - Tim ------------------------------------------------------------------------------ Flow-based real-time traffic analytics software. Cisco certified tool. Monitor traffic, SLAs, QoS, Medianet, WAAS etc. with NetFlow Analyzer Customize your own dashboards, set traffic alerts and generate reports. Network behavioral analysis & security monitoring. All-in-one tool. http://pubads.g.doubleclick.net/gampad/clk?id=126839071&iu=/4140/ostg.clktrk _______________________________________________ Dspace-devel mailing list Dspace-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dspace-devel
