engcoder
hello,
today i noticed that when a form getting data from a command subscribe from LS, it get some rows (add command) then all rows is deleted one by one (delete command). but when i close the form and open it again that do resubscribe, it get the last one row from LS.
what may cause the problem and is the LS may cache any data even it is received as deleted command from client?
Giuseppe Corti
Hi engcoder,
I confirm that the behavior experienced is not the one expected.
If the client subscribe an Item in COMMAND mode, the snapshot is the shortest sequence of commands needed to build the current state of the table from scratch. So, in case of an empty table the client should not receive anything.
In order to check what really happen, please could you replicate the case in a test environment after changing these log settings (in lightstreamer_log_conf.xml)?
[SYNTAX=XML]<logger name="LightstreamerLogger.pump" level="DEBUG"/>
<logger name="LightstreamerLogger.subscriptions" level="DEBUG">[/SYNTAX]
Regards,
Giuseppe
engcoder
this is the lightstreamer log file of today after i changed the log confg. as you showed
http://www.mediafire.com/download/q1cvg13a12za8sd/Lightstreamer+log+26-1-2016.rar
Giuseppe Corti
Hi engcoder,
I noticed that the log does not contain an isolated case, but multiple sessions with different subscriptions in COMMAND mode. I tried to verify some of these but I have not found the pattern complained.
Please could you point me inside the log precisely to the issue? For example, specifying a specific time or a session id and an Item involved in the issue.
Thank you,
Giuseppe
engcoder
hi,
i am not understand what is the isolated case and its benefit?
i don't remember the time of the problem but i guess it is not related to a time but it related to event that i noticed that when a form getting data from a command subscribe from LS, it get some rows (add command) then all rows is deleted one by one (delete command). but when i close the form and open it again that do resubscribe, it get the last one row from LS.
Giuseppe Corti
Hi engcoder,
By "isolated case" I mean:
- start a Lightstreamer server (for example a test or development server that are already in use) with the log settings suggested;
- connect with only a single client;
- repeating the minimum activities client-side to reproduce the issue;
- shut down the server.
In this way, the resulting log will be more compact and easier to read, helping us to identify the problem.
In any case, I have noticed that subscriptions for type COMMAND involving Items such these: pa11, pb11, pa2, ...
Could you tell us which of these should we examine?
Thank you,
Giuseppe
engcoder
hello,
i already do the isolatiotion for only one client outside the server and repeat activities.
you examine the subscribtions of items have the prefix pa and pb.
Giuseppe Corti
Hi engcoder,
I am sorry but I was not able to recognize the issue in the log.
However, I can report that I have often found messages like these:
26-Jan-16 16:02:55,272|DEBUG|LightstreamerLogger.subscriptions|ol.DataPool Notify Receiver|INCOMING DATA for pb11 on DataPool.DataPool --> ...
26-Jan-16 16:02:55,272|WARN |LightstreamerLogger.preprocessor |ol.DataPool Notify Receiver|Unexpected UPDATE event for key 33-p1-8. Event propagated as an ADD command.
This mean that when Lightstreamer server asks for the snapshot receives from your Adapter some UPDATE events. While, as snapshot events, only ADDs are expected.
Could be that the adapter send some of this UPDATEs incorrectly?
Regards,
Giuseppe
