Users getting disconnected when the sap cluster group failover happens.

[Former Member]

Hello all,

We have done the HA installation on mysaperp2005(ecc6.0).

The failover groups are sapcluster group(ascs+scs instance) and the Database(DB group).The central and the dialog instances are installed locally and do not form the part of the cluster.

When ever the sapcluster group failover to the second node.The users gets disconnected and need to login again.

How can we configure the nodes so that the users do not get disconnected during the failover of the sap groups and the users are not disturbed.

thanks

satyajit

[Former Member]

Hi marcus,

The diconnection occurs from the gui with the message

REP:connection to partner 192.168.0.77 broken:sapddp02

Connection reset by peer

and the system disconnects and then if we are trying to logon again it connects to the diffrent node.

Thanks

satyajit

[Former Member]

Hi Satyajit,

This is exactly the reason why it is called High Availability and not Full Availability.

When the node where Database runs fails, the memory structure (Instance) associated with the Database is lost and needs to be restarted on the other node. This means that all the transactions which have not been commited to the database needs to be rolled back. Hence the users doing insert/updates into the database will be disconnected from the System.

While the database is unavailable the Work processes go into a restart mode wherein they wait for the DB to come up again and keep pining it.

Database becomes available again after the Instance is started on the other node with Instance recovery and the users can connect back. Work processes recognize that the database is available and everything is back to normal.

In case of Central Instance (enqueue) failover, the lock information is lost and hence again the transactions need to be rolled back hence the users will be disconnected if they are doing an Insert/Update into the System. System becomes available once the Enqueue service is made available again after the failover.

So in either case there will be user disconnects as HA doesnot cover the memory structure failovers.

Hope this clears it up for you.

Thanks and Best Regards,

Sunil.

[Former Member]

Hello,

The database failover happens fast.but the user disconnects immeditely when the sap cluster group failover happens and he has to reconnect.

thx

satyajit

[markus_doehr2]

Disconnecting with what error message?

Markus

[markus_doehr2]

> How can we configure the nodes so that the users do not get disconnected during the failover of the sap groups and the users are not disturbed.

One reason can be that the database is taking too long to switch over and so the workprocesses don't wait long enough to get up again.

Markus