gco

Hi,

Yes, the heartbeat between two sites goes via ICMP traffic over WAN. GCO uses resource called WAC to form this heartbeat.

If you look at GAB output, GAB will not form a membership with remote site, GAB will have local membership with local nodes. You can identify remote nodes using "hastatus -sum" command which will show status of remote site

You can query status of heartbeat using "hahb" command ..

https://sort.symantec.com/public/documents/vcs/6.0/solaris/productguides/html/vcs_admin/ch18s02s06.htm

G

Hi,

Your understanding on GCO is right. Global Cluster Option(popularly known as GCO) is a global cluster formed from atleast 2 VCS clusters, each one in a separate site. This clusters are NOT geographically co-located(usually, separated by more than 80 kilometers).

HB between clusters: There is ICMP based heartbeat between clusters, which goes over the WAN. You can check remote clusters HB connectivity using “hahb” command.

E.g. In 2 cluster GCO(Pune and Mumbai), “hahb –state” executed from Pune gives connectivity between it and Mumbai cluster. 

# haclus -state
#Cluster     Attribute                Value
Pune         ClusState                RUNNING
Mumbai       ClusState                RUNNING

# hahb -state
#HB          Attribute     Scope      Value
Icmp         State         Mumbai     ALIVE

Message/State exchange between cluster: Wide-Area Connector(WAC) process runs on one of the node in each cluster. It is used for message/state exchange between clusters. This process listens for connection from remote clusters on port number 14155(default wac port). It is configured in ClusterService group.

GAB: GAB maintains membership between local nodes of a cluster. It never spans across clusters. 

Thanks & Regards,
Sunil Y