Hi @gang.chen1 and @ancoder

Just to confirm - to know the state of connectivity, you need to monitor the Status Msg for the Login Stream - not the market data item streams such as MarketPrice or others.

@gang.chen1 - regards your other question about - Received an item event with invalid message stream - this was asked previously by yourself: Received an item event with invalid message stream - Forum | Refinitiv Developer Community

Hi @gang.chen1

There is a related question on the forum - EMA C++ - Reconnection to ADS - Forum | Refinitiv Developer Community - which explains how to monitor the connection state and also EMA Webinar Nov 2: How are connection events handled (disconnections, buffer overflows, etc) - Forum | Refinitiv Developer Community

if you want to know the state of connectivity to a server within the application, you can manually register for the Login Domain stream.

Please refer to the 330__Login__Streaming example that comes with the SDK.

So, for example, if the DataState of your Login stream changes to Suspect, you know something is not right - but as long as the StreamState remains open - this should recover to DataState of OK. If however, it has not recovered after a while, you could try and reconnect.

OR, If the StreamState changes to Closed, then this indicates that the application has been logged out of the server and you would need to reconnect.

Since we added StreamState into monitoring, we got so many StatusMsgs with StreamState[CLOSED] as below

2022-05-18T15:20:33,874 ERROR 23600 [pool-5-thread-1] EmaClient 53 onStatusMsg - StreamState[CLOSED] in StatusMsg
    streamId="7"
    domain="MarketPrice Domain"
    state="Closed / Ok / None / 'Stream closed for batch'"
    serviceName="ELEKTRON_DD"
StatusMsgEnd

2022-05-18T15:20:33,883 ERROR 23609 [pool-5-thread-1] EmaClient 53 onStatusMsg - StreamState[CLOSED] in StatusMsg
    streamId="9"
    domain="MarketPrice Domain"
    state="Closed / Ok / None / 'Stream closed for batch'"
    serviceName="ELEKTRON_DD"
StatusMsgEnd

...

While subscribing to Chain of LSE : [0#LSE-ALL] and Chain of SGX : [0#A.SI, 0#B.SI, 0#C.SI, 0#D.SI, 0#E.SI, 0#F.SI, 0#G.SI, 0#H.SI, 0#I.SI, 0#J.SI, 0#K.SI, 0#L.SI, 0#M.SI, 0#N.SI, 0#O.SI, 0#P.SI, 0#Q.SI, 0#R.SI, 0#S.SI, 0#T.SI, 0#U.SI, 0#V.SI, 0#W.SI, 0#X.SI, 0#Y.SI, 0#Z.SI]

We wonder if it is normal and what could be the possible reasons for this...