Number of application instances/ server nodes - best practices

[Former Member]

Hello,

we are preparing project to adjust our Solman for all connected systems and activated functionalities. I used Quick sizer tool in order to count hardware demand however I would like to adjust number of application instances / server nodes as well.

Could you please share with me some hints and tips how to properly calculate it?

Thank you.

Monika

[patelyogesh]

What OS and DB are you planning to use?

-Yogesh

[Former Member]

Hi Yogesh,

I will use oracle on AIX.

Monika.

[oppancs · Accepted solution]

Dear Monika,

I can recommend some best practices from AS Java side for one instance:

In the AS Java there is no hard limitation for the number of nodes, but the recommended is to use up to 4 per instance.

In special cases, you can use up to 6 server nodes, but an overall higher overhead in multiple aspects can be noticed, for example, on native memory allocation.

The more nodes you have (server nodes and/or application instances), slower will be the overall startup. More information on Note 1794717.

The more nodes you have (server nodes) in an instance, slower/unresponsive the system can be, as the ICM or Dispatcher node, that balances the load and forward requests to the server nodes, will be overloaded. If this is the case the scenario must be reviewed to use more distributed elements.

It is preferred to increase the number of server nodes (up to 4), than to increase the heap size. Increasing the heap size will cause longer Garbage Collections (GC), and the overall performance will decrease. This is why the standard heap size recommendation is 2 GB, and preferably it is recommended to not use more than 5 GB, unless special cases due to application requirements.

32-bit systems are not recommended.

To create or remove server nodes in an appropriated way, you can use Note 1731107 for 7.0 releases, and Note 1734360 for 7.1 and higher releases.

In terms of heap size configuration, the following is used:

AS Java 7.0: Note 723909.
AS Java 7.1 and higher: Note 2548750.

When using specific applications and/or usage types, the application is the responsible to provide the sizing configuration, as each application has a different scenario and need different setups. In example, the standard AS Java recommendation is 2 GB of heap size, but with BW applications server nodes with less than 4GB can cause system crashes. More information on Note 1869544.

Best Regards,

Barnabás