Red Hat GFS 6.0 -, Administrator'S Manual

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40 Chapter 6. Creating the Cluster Configuration System Files
4. (Optional) For the heartbeat rate (
heartbeat_rate =
), specify
Seconds
. Refer to
Example 6-1.
The
Seconds
parameter in combination with the
allowed_misses
Number
parameter spec-
ify the amount of time for node failure detection as follows:
Seconds
x (
Number
+1) = Time (in seconds)
5. (Optional) For the allowed consecutively missed heartbeats (
allowed_misses =
), specify
Number
. Refer to Example 6-1.
6. Save the
cluster.ccs
file.
cluster {
name = " ClusterName "
lock_gulm {
servers = [" NodeName ",..., " NodeName "]
heartbeat_rate = Seconds <--
Optional
allowed_misses = Number <--
Optional
}
}
Figure 6-1. File Structure:
cluster.ccs
Parameter Description
ClusterName
The name of the cluster, from 1 to 16 characters long.
NodeName
The name of each node that runs the LOCK_GULM server. Each
node name must appear under
nodes.ccs:nodes
.
Seconds
(Optional) For the
heartbeat_rate =
parameter, the rate, in seconds, that a
master node checks for heartbeats from other nodes. The default
value of
Seconds
is 15. To ensure that nodes respond within the
Seconds
value, the interval for heartbeats sent by all nodes is
automatically set to two-thirds of the
Seconds
parameter value.
The
Seconds
parameter in combination with the
Number
parameter specify the amount of time for node failure detection as
follows:
Seconds
x (
Number
+1) = Time (in seconds).
To specify
Seconds
as a sub-second value, use floating point
notation; however, refer to the following caution for sub-second
values and other values less than the default value.
Caution: If you must adjust
Seconds
to a different value than the
default value, make sure that you understand in detail the
characteristics of your cluster hardware and software. Smaller
Seconds
values can cause false node expirations under heavy
network loads.
Number
(Optional) For
allowed_misses
, how many consecutive heartbeats can be
missed before a node is marked as expired. The default value of
Number
is 2. The
Seconds
parameter in combination with the
Number
parameter specify the amount of time for node failure
detection as follows:
Seconds
x (
Number
+1) = Time (in seconds).
Table 6-1. File Syntax Description: Variables for
cluster.ccs