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This chapter is from the book

Chapter Review Questions

1: What is the difference between an Active/Standby and a Rolling/Standby cluster configuration?

2: The disk/volume groups that are going to be shared between nodes in the cluster necessitate a different series of standard configuration files that normally deal with and manage disk/volumes/filesystems. Which standard configuration files are affected and why?

3: Looking at the following cluster ASCII configuration file, make any comments on the validity of this configuration:

# **********************************************************************
# ********* HIGH AVAILABILITY CLUSTER CONFIGURATION FILE ***************
# ***** For complete details about cluster parameters and how to    ****
# ***** set them, consult the Serviceguard manual. ****
# **********************************************************************

# Enter a name for this cluster. This name will be used to identify the
# cluster when viewing or manipulating it.

CLUSTER_NAME            finance


# Cluster Lock Parameters
#
# The cluster lock is used as a tiebreaker for situations
# in which a running cluster fails, and then two equal-sized
# sub-clusters are both trying to form a new cluster. The
# cluster lock may be configured using either a lock disk
# or a quorum server.
#
# You can use either the quorum server or the lock disk as
# a cluster lock but not both in the same cluster.
#
# Consider the following when configuring a cluster.
# For a two-node cluster, you must use a cluster lock. For
# a cluster of three or four nodes, a cluster lock is strongly
# recommended. For a cluster of more than four nodes, a
# cluster lock is recommended. If you decide to configure
# a lock for a cluster of more than four nodes, it must be
# a quorum server.

# Lock Disk Parameters. Use the FIRST_CLUSTER_LOCK_VG and
# FIRST_CLUSTER_LOCK_PV parameters to define a lock disk.
# The FIRST_CLUSTER_LOCK_VG is the LVM volume group that
# holds the cluster lock. This volume group should not be
# used by any other cluster as a cluster lock device.

# Quorum Server Parameters. Use the QS_HOST, QS_POLLING_INTERVAL,
# and QS_TIMEOUT_EXTENSION parameters to define a quorum server.
# The QS_HOST is the host name or IP address of the system
# that is running the quorum server process. The
# QS_POLLING_INTERVAL (microseconds) is the interval at which
# Serviceguard checks to make sure the quorum server is running.
# The optional QS_TIMEOUT_EXTENSION (microseconds) is used to increase
# the time interval after which the quorum server is marked DOWN.
#
# The default quorum server timeout is calculated from the
# Serviceguard cluster parameters, including NODE_TIMEOUT and
# HEARTBEAT_INTERVAL. If you are experiencing quorum server
# timeouts, you can adjust these parameters, or you can include
# the QS_TIMEOUT_EXTENSION parameter.
#
# For example, to configure a quorum server running on node
# "qshost" with 120 seconds for the QS_POLLING_INTERVAL and to
# add 2 seconds to the system assigned value for the quorum server
# timeout, enter:
#
# QS_HOST qshost
# QS_POLLING_INTERVAL 120000000
# QS_TIMEOUT_EXTENSION 2000000

FIRST_CLUSTER_LOCK_VG           /dev/vg01


# Definition of nodes in the cluster.
# Repeat node definitions as necessary for additional nodes.

NODE_NAME               fin01
  NETWORK_INTERFACE     lan0
    HEARTBEAT_IP                192.1.1.1
  NETWORK_INTERFACE     lan1
  FIRST_CLUSTER_LOCK_PV /dev/dsk/c1t0d0
# List of serial device file names
# For example:
SERIAL_DEVICE_FILE    /dev/tty0p0

# Possible standby Network Interfaces for lan0: lan1.

NODE_NAME               fin02
  NETWORK_INTERFACE     lan0
    HEARTBEAT_IP                192.1.1.2
  NETWORK_INTERFACE     lan1
  FIRST_CLUSTER_LOCK_PV /dev/dsk/c0t0d0
# List of serial device file names
# For example:
SERIAL_DEVICE_FILE    /dev/tty0p0

# Possible standby Network Interfaces for lan0: lan1.

NODE_NAME               fin03
  NETWORK_INTERFACE     lan0
    HEARTBEAT_IP                192.1.1.3
  NETWORK_INTERFACE     lan1
  FIRST_CLUSTER_LOCK_PV /dev/dsk/c0t0d0
# List of serial device file names
# For example:
SERIAL_DEVICE_FILE    /dev/tty0p0

# Possible standby Network Interfaces for lan0: lan1.

NODE_NAME               fin04
  NETWORK_INTERFACE     lan0
    HEARTBEAT_IP                192.1.1.4
  NETWORK_INTERFACE     lan1
  FIRST_CLUSTER_LOCK_PV /dev/dsk/c0t0d0
# List of serial device file names
# For example:
SERIAL_DEVICE_FILE    /dev/tty0p0

# Possible standby Network Interfaces for lan0: lan1.

# Cluster Timing Parameters (microseconds).
# The NODE_TIMEOUT parameter defaults to 2000000 (2 seconds).
# This default setting yields the fastest cluster reformations.
# However, the use of the default value increases the potential
# for spurious reformations due to momentary system hangs or
# network load spikes.
# For a significant portion of installations, a setting of
# 5000000 to 8000000 (5 to 8 seconds) is more appropriate.
# The maximum value recommended for NODE_TIMEOUT is 30000000
# (30 seconds).

HEARTBEAT_INTERVAL              6000000
NODE_TIMEOUT            5000000

# Configuration/Reconfiguration Timing Parameters (microseconds).

AUTO_START_TIMEOUT      600000000
NETWORK_POLLING_INTERVAL        2000000

# Package Configuration Parameters.
# Enter the maximum number of packages which will be configured in the
# cluster.
# You can not add packages beyond this limit.
# This parameter is required.
MAX_CONFIGURED_PACKAGES         10

# List of cluster aware LVM Volume Groups. These volume groups will
# be used by package applications via the vgchange -a e command.
# Neither CVM or VxVM Disk Groups should be used here.
# For example:
# VOLUME_GROUP          /dev/vgdatabase
# VOLUME_GROUP          /dev/vg02

VOLUME_GROUP            /dev/vg01

4: Explain why the Cluster Management Daemon (cmcld) is run at an HP-UX Real-Time Priority of 20. Does this have any implications on how we manage our own processes/applications?

5: Where is the configuration parameter AUTOSTART_CMCLD stored? What is its default value? What does this parameter control? Give at least three reasons why you would set the configuration parameter AUTOSTART_CMCLD=0.

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