The fix is ready and checked into SVN.
sorry for inconvenience :(

On Sun, Nov 20, 2011 at 18:26, [email protected]
<[email protected]>wrote:

> Thanks!
>
>
> 2011/11/20 Maxim Solodovnik <[email protected]>
>
>> OK sure
>> RoomClient was the part of RoomPoll this is why I have moved it into DB
>> I will make the fix immediately
>>
>>
>> On Sun, Nov 20, 2011 at 18:23, [email protected] <
>> [email protected]> wrote:
>>
>>> The query should be:
>>> SELECT RoomClient where room_id = :room_id and isScreenSharing != true
>>>
>>> Anyhow, I have to admit that I would really liek to get rid of the
>>> RoomClient from the database. The RoomClient is a session object.
>>> Storing session variables in a database is never a good approach.
>>> If we need to have a caching control over the RoomClient we should use
>>> something like Ehcache (http://ehcache.org/).
>>>
>>> If you need the RoomClient as reference under some circumstances you can
>>> still store it "on demand", meaning: You persist the RoomClient only if
>>> there is really something to store that has this RoomClient as reference.
>>> I don't really understand why you needed it for the poll feature,
>>> actually also your implementation does delete all roomclients when the room
>>> is empty (at least I hope so :D otherwise we have another problem :)))).
>>> So if you delete the RoomClient anyway => what should anybody reference
>>> this temp RoomClient object if it will be gone again.
>>>
>>> So please make the RoomClient a static variable in the again, we will
>>> have to think about how to really solve it using a caching mechanism but
>>> using the database as session cache is not working.
>>>
>>>
>>> Sebastian
>>>
>>> 2011/11/20 Maxim Solodovnik <[email protected]>
>>>
>>>> Since the is selection from the DB I will iterate only to get the list
>>>> of IDs the call sometheng like:
>>>>
>>>> SELECT RoomClient where id IN(...)
>>>>
>>>> OK I will implement your logic tonight
>>>>
>>>>
>>>> On Sun, Nov 20, 2011 at 17:45, [email protected] <
>>>> [email protected]> wrote:
>>>>
>>>>> Returning a Set<RoomClients> based on the a list of streamid ... you
>>>>> would need to collect all streamids and iterate two times to the clients
>>>>> and a third time to get the RoomCLient from the Set then .... I would not
>>>>> do that.
>>>>>
>>>>> *1 Basic approach*
>>>>> Those sync methods => they will always iterate through all clients of
>>>>> ONE room
>>>>> ... so you can get those RoomClient BEFORE you iterate through the
>>>>> connections
>>>>> ... and you return a java.util.Map with the streamid as key, so that
>>>>> you can access those RoomClients fast
>>>>> public Map<RoomClient> getRoomClientsByRoomId
>>>>>
>>>>> I still think it would perform better to have no Select at all,
>>>>> however ...
>>>>> doing like that would result in just a single select so I guess we
>>>>> could give it a try.
>>>>>
>>>>> *1A => Extend that basic approach with isScreenClient *
>>>>> This could be a basic solution. But additionally those sync methods
>>>>> always check for one attribute right now:
>>>>> rcl.getIsScreenClient() != null && rcl.getIsScreenClient()
>>>>> => because if the RoomClient is a ScreenSharing Connection => we of
>>>>> course don't want to send this client a whiteboard object!
>>>>>
>>>>> So the method should be:
>>>>> public Map<RoomClient> getRoomClientsForWhiteboardByRoomId(Long roomId)
>>>>> => and only return those clients where isScreenClient != true
>>>>> And in the iteration you need to check if the returning Map
>>>>> containKey(streamid) => to verify we don't send the wrong connection our
>>>>> objects to
>>>>>
>>>>> *1B => Extend that basic approach with upcoming audio/video components
>>>>> *
>>>>> German & Timur's solution with separated Audio/video components will
>>>>> have another effect:
>>>>> We will have two Connections to each Flash client, but we want ONLY
>>>>> ONE to send our whitbeoard objects to.
>>>>> So in a later extension the method:
>>>>> public Map<RoomClient> getRoomClientsForWhiteboardByRoomId(Long roomId)
>>>>> Has to do a SELECT where it only returns those RoomClients that are
>>>>> really the "main-netconnection".
>>>>>
>>>>>
>>>>> 1
>>>>> +
>>>>> 1 A
>>>>>
>>>>> should be done right now,
>>>>>
>>>>> 1 B is something we can do in a second step.
>>>>>
>>>>> Of course it might be needed in some circumstances to think about if
>>>>> it makes sense to have also the ScreenSharing clients in the returning 
>>>>> Map,
>>>>> but the standard use-case will be NOT to have them.
>>>>>
>>>>>
>>>>> Sebastian
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> 2011/11/20 Maxim Solodovnik <[email protected]>
>>>>>
>>>>>> Hello Sebastian,
>>>>>>
>>>>>> I haven't test so much clients, I have no server with big number of
>>>>>> attendees.
>>>>>> To resolve the issue I can write a method in clientListManager which
>>>>>> will accept Set<IConnection> as a parameter and return all roomClients 
>>>>>> with
>>>>>> ids passed in one request.
>>>>>>
>>>>>> Or if you feel this would be performance degradation I can move
>>>>>> RoomClient out of database.
>>>>>> It was necessary bacause in old designs RoomPolls has references to
>>>>>> RoomClient, currently it references Users, so it might me easily removed
>>>>>> from the DB and will affect nothing.
>>>>>>
>>>>>>
>>>>>> On Sun, Nov 20, 2011 at 16:46, [email protected] <
>>>>>> [email protected]> wrote:
>>>>>>
>>>>>>> Hi Maxim,
>>>>>>>
>>>>>>> I would like to discuss a design problem of the new architecture to
>>>>>>> store the RoomClients in the database.
>>>>>>>
>>>>>>> Did you see that when iterating through the connections for example
>>>>>>> in the method:
>>>>>>>
>>>>>>> http://code.google.com/p/openmeetings/source/browse/trunk/singlewebapp/src/app/org/openmeetings/app/remote/red5/ScopeApplicationAdapter.java#2504
>>>>>>>
>>>>>>> You request on each connection, everytime you iterate throuhg a
>>>>>>> SINGLE SELECT on the database to get the roomclient ?!
>>>>>>> Meaning if you have 200 people in a conference room you make 200
>>>>>>> single select statements on the database, and as that happens for 
>>>>>>> example
>>>>>>> for each time the green dod in video-views starts or stops to blink, or
>>>>>>> each time the users sends a new whiteboard event ...actually everytime 
>>>>>>> you
>>>>>>> sync ANYTHING to your participants the server will iterate through all
>>>>>>> session objects and then does now a SINGLE query for each connection
>>>>>>> getting the corresponding RoomClient from the DB.
>>>>>>>
>>>>>>> Did you ever test the effect when having lets say 500 participants
>>>>>>> online, and 150 in a single room and now you send a whiteboard event, 
>>>>>>> how
>>>>>>> long does it take?! I mean we make a real-time application? This
>>>>>>> implementation does not scale at all. That was the reason why the
>>>>>>> RoomClient was a static variable of type HashMap and not in the 
>>>>>>> database.
>>>>>>> To be able to access it really FAST. Red5 does something similar for
>>>>>>> "sharedObjects" it stores them in the session (using ehCache I think).
>>>>>>>
>>>>>>> However, there is really need for immediatelly change in that part,
>>>>>>> making a single selct ON EACH CONNECTION => this will not fly!
>>>>>>>
>>>>>>> Can you please propose some concept on that, so we discuss this
>>>>>>> together and then implement it.
>>>>>>>
>>>>>>>
>>>>>>> Sebastian
>>>>>>>
>>>>>>> --
>>>>>>> Sebastian Wagner
>>>>>>> http://www.openmeetings.de
>>>>>>> http://www.webbase-design.de
>>>>>>> http://www.wagner-sebastian.com
>>>>>>> [email protected]
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> WBR
>>>>>> Maxim aka solomax
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Sebastian Wagner
>>>>> http://www.openmeetings.de
>>>>> http://www.webbase-design.de
>>>>> http://www.wagner-sebastian.com
>>>>> [email protected]
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> WBR
>>>> Maxim aka solomax
>>>>
>>>
>>>
>>>
>>> --
>>> Sebastian Wagner
>>> http://www.openmeetings.de
>>> http://www.webbase-design.de
>>> http://www.wagner-sebastian.com
>>> [email protected]
>>>
>>
>>
>>
>> --
>> WBR
>> Maxim aka solomax
>>
>
>
>
> --
> Sebastian Wagner
> http://www.openmeetings.de
> http://www.webbase-design.de
> http://www.wagner-sebastian.com
> [email protected]
>



-- 
WBR
Maxim aka solomax

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