Best Practices for SGeRAC and Oracle RAC on HP-UX 11i, March 2009

Alternate configuration – fast reconfiguration with low heartbeat timeout

Figure 4. Alternative configuration – low Serviceguard member timeout

When RAC-DB-IC traffic is very high and SG-HB timeout is low, there is a probability of RAC-DB-IC

traffic interfering with SG-HB traffic and causing unnecessary timeouts. If SG-HB timeout can not be

increased, then an alternative action is to use a second network for SG-HB. This configuration is for

environments that need fast failover (low Serviceguard member timeout) for two or more nodes.

Each primary and standby pair protects against single failure. With SG-HB on more than one subnet,

a single subnet failure will not trigger a SG reconfiguration. If the subnet with CSS-HB fails, unless

subnet monitoring is used, CSS will resolve the subnet interconnect failure with a CSS cluster

reconfiguration.

Note:

Starting with Serviceguard A.11.19, the faster failover capability is

integrated with the base Serviceguard product. This configuration can be

used for faster failover.

Timeouts

The SG-HB timeout (MEMBER_TIMEOUT) should be set based on service availability requirements.

Optionally if CSS-HB timeout is changed, the CSS-HB timeout should be tuned to provide an

opportunity for Serviceguard to complete reconfiguration and update CSS through group membership

service (GMS) prior to CSS timeout. Optionally if RAC-DB-IC timeout is changed, RAC-DB-IC timeout

should be 15 seconds above CSS-HB timeout. Note that the timeout relations are slightly different

when using Cluster Interconnect Subnet monitoring.

Subnet monitoring or Cluster Interconnect Subnet monitoring

Serviceguard packages can be configured with a subnet dependency on the CSS-HB subnet and

FAIL_FAST enabled. If both LAN1 and lan2 failed, the Serviceguard package can request halting the

node where the interconnect failure is detected. Use of Serviceguard subnet monitoring has a

Node A

LAN 1

Node B

HB2

Private

(primary)

Private

(standby)

Private

(primary)

LAN 1

LAN 2

HB1

CSS-HB

RAC-DB1-IC

Private

(standby)

LAN 2

LAN 4

LAN 3