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

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