Transparent Application Failover Support --> some questions
Posted: Tue 11 Jan 2011 15:44
Hello,
I have some questions about the TAF-support in dotConnect. Possibly it could be that TAF is totally the wrong thing in our requirements.
Currently we are already using some years the corelab-devart-dotconnect and are really happy about it.
But we did have some discussion about what could happens with an active-open OracleConnection object, and for some reason the application can not reach the DB (Ex; DB down, network troubles,....)
If you execute a OracleReader on that connection --> what will happen and does comes TAF here in to play? Knowing that we have currently a single instance DB (not yet a cluster)
Is there some mechanismn possible that will start in that situation and say tries some times to auto-reconnect ? (This is what TAF does) --> but does this also works when the client can not reach the DB (has no network at all)
I did tried a simple test, and created the connection + open. Also attached the TAF-failover event. I executed a query which was OK.
I then fysically removed my lan-cable, and tried the query again. My app was in some waiting-mode then. But when I re-attached my lan-cable, nothing TAF-happens, only an exception was thrown. Which stated some TNS writing problems....
PS: I did not tested what happens when I do NOT reconnect my lan-cable. will there be some oracle-timeout-exception in the end ?
I do not know if this kind of connection-loss-problems can be auto-solved by TAF ? Or are there some other functionalities possible ?
Thx,
Fred
I have some questions about the TAF-support in dotConnect. Possibly it could be that TAF is totally the wrong thing in our requirements.
Currently we are already using some years the corelab-devart-dotconnect and are really happy about it.
But we did have some discussion about what could happens with an active-open OracleConnection object, and for some reason the application can not reach the DB (Ex; DB down, network troubles,....)
If you execute a OracleReader on that connection --> what will happen and does comes TAF here in to play? Knowing that we have currently a single instance DB (not yet a cluster)
Is there some mechanismn possible that will start in that situation and say tries some times to auto-reconnect ? (This is what TAF does) --> but does this also works when the client can not reach the DB (has no network at all)
I did tried a simple test, and created the connection + open. Also attached the TAF-failover event. I executed a query which was OK.
I then fysically removed my lan-cable, and tried the query again. My app was in some waiting-mode then. But when I re-attached my lan-cable, nothing TAF-happens, only an exception was thrown. Which stated some TNS writing problems....
PS: I did not tested what happens when I do NOT reconnect my lan-cable. will there be some oracle-timeout-exception in the end ?
I do not know if this kind of connection-loss-problems can be auto-solved by TAF ? Or are there some other functionalities possible ?
Thx,
Fred