Feature #375

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Better remote backend reconnect handling

Added by Michael Elsdörfer 5129 days ago. Updated 4536 days ago.

Status:Closed Start:05/07/2010
Priority:Normal Due date:
Assigned to:avatarMirco Bauer % Done:

100%

Category:Frontend GNOME
Target version:0.8.9
Complexity:

Medium

Votes: 0

Description

I'm using Smuxi with a remote backend. If I loose connection to the server, which is at least one a day, but frequently happens more often than that of course, Smuxi will show a dialog in the current virtual workspace, asking me if I would like to reconnect. If I respond yes, it'll move the main window to the current workspace, and I need to move it back.

I would argue that the dialog is wholly unnecessary - Upon losing the connection, Smuxi should automatically try to reconnect - the user doesn't even need to know that the connection was gone. If reconnection fails, further attempts could be delayed, with the delay slowly increasing etc.

The interface would reflect the disconnected state, and all the user to request a manual reconnect at any time.

Associated revisions

Revision 75c554063336e77efbf3e30440a5787ba2826154
Added by Mirco Bauer 4651 days ago

[Frontend-GNOME] Auto-reconnect to smuxi-server if frontend has no focus (closes: #375)

Revision a437464198da1dfccd4e4c78789974933d4012ab
Added by Mirco Bauer 4651 days ago

[Frontend-GNOME] Auto-reconnect to smuxi-server if frontend has no focus (closes: #375)

Revision 8a42c4253391843945c3894d2cdb18a898e540f9
Added by Mirco Bauer 4651 days ago

[Frontend/Frontend-GNOME] Implemented background and concurrent chat sync (references: #375)

Instead of adding and syncing each chat at a time in the GUI thread and thus
block the GUI from refreshing, we are now using a thread pool with 4 worker
threads which add and sync the chats in the background and only populating the
retreived data is done in the GUI thread. This makes the frontend connect
faster, feels much more responsive and even allows to use the synced chats
already while it is still syncing the remaining ones.

Implemented the ChatViewSyncManager class which queues and processes the
AddChat and SyncChat calls using the ThreadPoolQueue.

Added Sync() to IChatView which the ChatViewSyncManager will call from a
thread pool worker thread and thus must be implemented thread-safely.

Added Populate() to IChatView which the ChatViewManager will call from it's
ChatViewSyncManager.ChatSynced handler to populate the data into the GUI.

Added ID and Position property to IChatView which the ChatViewManager will
call to populate the data before ChatViewSyncManager.ChatAdded will be raised
from a thread pool worker thread and thus must be implemented thread-safely.

Summary of the sync API workflow: - FrontendManager.Sync() calls IFrontendUI.AddChat() and SyncChat() via
.NET remoting.
/> - IFrontendUI.AddChat() calls ChatViewSyncManager.QueueAdd().
- IFrontendUI.SyncChat() calls ChatViewSyncManager.QueueSync().
/> - ChatViewSyncManager queues the Add and Sync requests to ThreadPoolQueue.
- ChatViewSyncManager.QueueAdd() create a sync lock to make sure a sync
processor will not run before the chat was added to the frontend.
- ChatViewSyncManager's add worker will fetch ID, ChatType, Position and
ProtocolManagerType from a thread pool worker thread and raises the
ChatAdded event.
/> - ChatViewManager's ChatViewSyncManager.ChatAdded handler adds the chat to
the GUI and calls ChatViewSyncManager.ReleaseSync() to signal the possibly
waiting thread pool worker thread.
/> - ChatViewSyncManager's sync worker optionally honors a sync lock and then
calls IChatView.Sync() from a thread pool worker thread and raises the
ChatSynced event.
/> - IChatView.Sync() fetches all the data it needs from the ChatModel via
.NET remoting.
- ChatViewManager's ChatViewSyncManager.ChatSynced handler calls
IChatView.Populate() from the GUI thread.
- IChatView.Populate() pushes the fetched data into the GUI.

/>

History

Updated by Mirco Bauer 5056 days ago

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  • Category set to Frontend GNOME
  • Complexity set to Medium

The problem with auto-reconnecting to the smuxi-server could make the user think the application is hanging. Around Smuxi 0.8 I plan to introduce a progress dialog when connecting to a smuxi-server which could solve this issue with auto-reconnecting. Does this sound acceptable for you? Auto-reconnect while showing that it lost the connection and is reconnecting? One other issue is that the reconnect might fail, say your network or internet is down, in that case the connect dialog could show the failed attempt though.

Updated by Michael Elsdörfer 5055 days ago

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Mirco Bauer wrote:

The problem with auto-reconnecting to the smuxi-server could make the user think the application is hanging.

No, the main Smuxi Window would need to make the user aware of what is going on - by graying out the interface, or maybe showing a big "I am reconnecting right now"-overlay on top of everything. I just think that from a UI perspective, this is vastly superior to any dialog:

- As long as Smuxi is in the background, behind some other window, or on a different workspace, I don't see why the user would care about the connection being lost. He shouldn't be bothered. He is not interacting with Smuxi right now. There's nothing he gains from it; at best, he can press the "Yes, reconnect" button, something that could happen automatically.

- As soon as the user decides he wants to interact with Smuxi, the window will clearly indicate the current connection status and the reconnection attempt. The user will know about the connection loss right when he needs to, but not earlier.

One other issue is that the reconnect might fail, say your network or internet is down, in that case the connect dialog could show the failed attempt though.

Again, I don't think it should. Not intrusively. Show it within the Smuxi window, of course. If you judge it important, I suggest that a notification could be displayed, or an indicator. When my connection fails, I don't want to be bombarded by all kinds of applications about their connection troubles. I think Smuxi should behave like most instant messenger apps do: If you lose the connection, try to reconnect as soon as possible, using a delayed reconnect loop, i.e. wait a little bit longer after each failed reconnect attempt. In the meantime, change the indicator icon to something that says "offline".

Also, with respect to the hanging, I notice that this happens from time to time in the UI when Smuxi is communicating with the server. For example, when I say "Yes" in the reconnection dialog, the UI is frozen for a couple of seconds until the reconnect is complete. It seems like the network communication is happening in the UI thread. A better architecture would keep the UI responsive at all times, and simply show a spinning "i am busy" icon.

Updated by Mirco Bauer 4655 days ago

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Auto-reconnect to smuxi-server when Smuxi is not focused is a very good idea. The user wouldn't notice anyhow and would not be faced with a reconnect nag dialog if he wants to chat... Of course when the reconnect is happening the user should be able to see that, else he would believe Smuxi is suddenly not working correctly.

Updated by Mirco Bauer 4651 days ago

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  • Assigned to set to Mirco Bauer
  • Target version set to 0.8.9

Updated by Mirco Bauer 4651 days ago

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  • Status changed from New to Closed
  • % Done changed from 0 to 100

Updated by Mirco Bauer 4536 days ago

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This change can be tested with a development build which can be obtained from here: http://www.smuxi.org/documentation/running-from-git/

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