How to add a HANA multi node cluster on Studio

[Former Member]

Hi all,

we have a 5 node HANA cluster db and i am trying to find a way to add multiple hostnames to studio so that incase a node goes down the studio tries to acess the other available nodes .

Thank you

Jonu Joy

[lbreddemann]

You simply add one address.

Upon request, the JDBC client will find the other possible servers.

- Lars

[Former Member]

Thank you lars, but if the node which we have defined in studio crashes( not pingable) then how does the studio know which other servers are part of the custer in order to reach them .

Thank you

Jonu Joy

[lbreddemann]

Upon first connect the server provides a list of possible other servers.

SAP HANA studio remembers this list and will try the other connections for reconnection.

If you want to specifically be able to connect to one of the servers, then you'll have to setup an logon entry for these servers.

- Lars

[Former Member]

  thank you lars, would you know if its possible to see the list which studio remembers, is it stored on the filesystem and viewable .

Thank you

Jonu Joy

[lbreddemann]

It can be reviewed in the logon property details.

- Lars

[Former Member]

We have a 5 node cluster and when i checked the studio i see only 2 nodes in the Hosts used to connect list .

[lbreddemann]

Hey Jonu,

correct, the list there is a bit misleading.

What it seems to display is the list of hosts that either are MASTER or SLAVE coordinators in distributed systems. (check against M_SERVICES.COORDINATOR_TYPE).

In the HANA Studio you can check the "Index Server Role (actual)" for this.

In addition to this, the list will contain any host you explicitly entered into the connection detail when you defined the connection.

Anyhow, the complete list of all hosts and there roles is also stored in the system landscape file:

.. \hdbstudio\.metadata\.plugins\com.sap.ndb.studio.datamodel\hdbstudio.xml

In case the MASTER host is not reachable, the STANDBY node is tried to get connection information.If this one is either not reachable either or reports to be not the MASTER yet (because no take over occurred) the connection will fail.

Once one of the coordinators is actually reached, the current landscape information will be delivered to the client again and the SQL connection can be established with one of the available SQL services.

Hope that makes it a bit easier to understand.

- Lars