Dynamic Node addition & Cluster status update for SG Cluster

[vijay_78]

Hi All,

we are looking for the following functionality in ServiceGuard.

1) Adding new nodes to MC/SG Cluster, without bringing down existing application packages /nodes in the existing cluster.

2).Updating the cluster configurations/status dynamically through APIs, so as to carry out some mainteneance activities, without bringing down the application packages.

Does MC/ServiceGuard supports these features out-of-the-box?. if not, does it provide APIs to support the above features?.

Thanks for the help

Regards,
Vijay

[Ramesh S]

Hi

For answering to your first question

Adding a server to a running cluster is permissible.If a package configuration file was modified to add the new server as another
resource NODE_NAME, it will be necessary to halt the package before performing the cmapplyconf command.

1.Configure the new node to access the cluster and package resources.

2.Updating the Cluster ASCII configuration file

3.Updating the server name to any package configuration files

4.Use the cmapplyconf command to update the cluster binary file

A node can only be added to a cluster when it has the same version of ServiceGuard loaded that is operating on the cluster.It is permissible to mix operating system revisions on cluster nodes as long as they all have the same version of serviceGuard loaded.

I dont know anything about API.

Hope this helps you!!

Thanks & Regards

Ramesh

[melvyn burnard]

you can add a node without taking down the cluster PROVIDED that you do not break some rules, one example being adding a fifth node to a four node cluster that is using a cluster lock disk, as this would first require the cluster lock disk being removed from the configuration. In most cases it is simply making sure you have the same version of SG and patches, making sure you have the networking configured correctly, and the storage connectivity is worked out.

Depending upon the version of SG, there are a number of things you can/cannot do with a pakcage up, or the cluster up.
I suggest you read the Managing Serviceguard manual for the version of SG you are using available at:
http://docs.hp.com/en/ha

Also, please note the product has not been called MC/ServiceGuard or MC/SG for many years now, the correct name is just Serviceguard (note the lower case g)

[Stephen Doud]

As Melvyn said, you can add nodes to a cluster within constraints that are specified in the manual.

As for modifying the cluster status without bringing down a package, please tell us what you have in mind. Before I can comment, I need to know what you want to do in more detail.

If you want to, say, shut down an application within a package without halting the package, that is possible.

If you want to do the reverse, and halt a package without actually relinquishing system resources or halting the application, then it this too is possible but if falls outside of HP supported techniques.

If you want to halt Serviceguard daemons on a node or halt a cluster but leave the package resources available, this too falls outside HP-supportable techniques, but may be possible.

Please detail your goal.