Chapter 2. Clustering

RRP does not work when the IP address/port number pairs are the same or the IP versions are mixed. Corosync now checks whether the network interfaces have a different IP address/port number pair and whether they use the same IP version.

The fence_ilo_ssh fencing agent is a fence agent that connects to an iLO device. It logs into the device via ssh and reboots a specified outlet. For information on the parameters for the fence_ilo_ssh fencing agent, see the fence_ilo_ssh(8) man page.

The fence_mpath fencing agent is an I/O fencing agent that uses SCSI-3 persistent reservations to control access to multipath devices. For information on the operation of this fencing agent and for descriptions of its parameters, see the fence_mpath(8) man page.

Previously, when using UDPU, all messages were sent to all configured members, as opposed to only the active members. This is appropriate for merge detection messages, but for everything else it creates unnecessary traffic to missing members and may trigger excessive arp requests on the network. Corosync has been modified to send most UDPU messages to active members only, with the exception of messages required for proper detection of merge or new member (1-2 pkts/sec).

The resource-agents-sap-hana package provides two Pacemaker resource agents, SAPHanaTopology and SAPHana. These resource agents allow you to configure a Pacemaker cluster to manage a SAP HANA Scale-Up System Replication environment on Red Hat Enterprise Linux.

The fence_emerson fencing agent is a fence agent for Emerson over SNMP. It is an I/O fencing agent that can be used with MPX and MPH2 managed rack PDU. For information on the parameters for the fence_emerson fencing agent, see the fence_emerson(8) man page.