Red Hat Summit11.5.4.2. Topology Change Headers for Topology-Aware Clients
The response header sent to topology-aware clients when a topology change is returned by the server includes the following elements:
| Response Header Fields | Data Type/Size | Details |
|---|---|---|
| Response Header with Topology Change Marker | - | - |
| Topology ID | vInt | - |
| Num Servers in Topology | vInt | Contains the number of Hot Rod servers running in the cluster. This value can be a subset of the entire cluster if only some nodes are running Hot Rod servers. |
| mX: Host/IP Length | vInt | Contains the length of the hostname or IP address of an individual cluster member. Variable length allows this element to include hostnames, IPv4 and IPv6 addresses. |
| mX: Host/IP Address | string | Contains the hostname or IP address of an individual cluster member. The Hot Rod client uses this information to access the individual cluster member. |
| mX: Port | Unsigned Short. 2 bytes | Contains the port used by Hot Rod clients to communicate with the cluster member. |
The three entries with the prefix
mX, are repeated for each server in the topology. The first server in the topology's information fields will be prefixed with m1 and the numerical value is incremented by one for each additional server till the value of X equals the number of servers specified in the num servers in topology field.
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