Download Red Hat Enterprise Linux 7 7.1 Release Notes

Red Hat Ent erprise Linux 7 7 .1 Release Not es
Chapter 8. Clustering
Dynamic T oken T imeout for Corosync
The to ken_co effi ci ent option has been added to the C o ro sync C l uster Eng i ne. The value
of to ken_co effi ci ent is used only when the no d el i st section is specified and contains at least
three nodes. In such a situation, the token timeout is computed as follows:
[token + (amount of nodes - 2)] * token_coefficient
This allows the cluster to scale without manually changing the token timeout every time a new node is
added. The default value is 650 milliseconds, but it can be set to 0, resulting in effective removal of
this feature.
This feature allows C o ro sync to handle dynamic addition and removal of nodes.
Corosync T ie Breaker Enhancement
The auto _ti e_breaker quorum feature of C o ro sync has been enhanced to provide options for
more flexible configuration and modification of tie breaker nodes. Users can now select a list of
nodes that will retain a quorum in case of an even cluster split, or choose that a quorum will be
retained by the node with the lowest node ID or the highest node ID .
Enhancement s for Red Hat High Availabilit y
For the Red Hat Enterprise Linux 7.1 release, the R ed Hat Hi g h Avai l abi l i ty Ad d -O n
supports the following features. For information on these features, see the High Availability Add-On
Reference manual.
The pcs reso urce cl eanup command can now reset the resource status and fai l co unt for
all resources.
You can specify a l i feti me parameter for the pcs reso urce mo ve command to indicate a
period of time that the resource constraint this command creates will remain in effect.
You can use the pcs acl command to set permissions for local users to allow read-only or readwrite access to the cluster configuration by using access control lists (ACLs).
The pcs co nstrai nt command now supports the configuration of specific constraint options in
addition to general resource options.
The pcs reso urce create command supports the d i sabl ed parameter to indicate that the
resource being created is not started automatically.
The pcs cl uster q uo rum unbl o ck command prevents the cluster from waiting for all nodes
when establishing a quorum.
You can configure resource group order with the befo re and after parameters of the pcs
reso urce create command.
You can back up the cluster configuration in a tarball and restore the cluster configuration files
on all nodes from backup with the backup and resto re options of the pcs co nfi g command.
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