IBM z/OS - page 44

Automatic Enablement of CBU for Geographically Dispersed

Parallel Sysplex

The intent of the GDPS (CBU) is to enable automatic man-

agement of the reserved PUs provided by the CBU feature

in the event of a processor failure and/or a site failure.

Upon detection of a site failure, GDPS will dynamically

add PUs to the conﬁ guration in the takeover site to restore

processing power for mission-critical production work-

loads. GDPS-CBU management helps to minimize manual

customer intervention and the potential for errors, thereby

helping to reduce the outage time for critical workloads

from hours to minutes. Similarly, GDPS-CBU management

can also automate the process of dynamically returning

the reserved CPs when the temporary period has expired.

GDPS is discussed in a white paper available at ibm.com/

server/eserver/zseries/pso/library.html. GDPS is a service

offering of IBM Global Services. For IBM Installation Ser-

vices for GDPS, refer to the IBM Web site.

Message Time Ordering (Sysplex Timer Connectivity to Coupling

Facilities)

As processor and Coupling Facility link technologies have

improved over the years, the requirement for time synchro-

nization tolerance between systems in a Parallel Sysplex

environment has become ever more rigorous. In order

to ensure that any exchanges of timestamped informa-

tion between systems in a sysplex involving the Coupling

Facility observe the correct time ordering, time stamps are

now included in the message-transfer protocol between

the systems and the Coupling Facility. Therefore, when a

Coupling Facility is conﬁ gured as an ICF on any z990 or

z900 Models 2C1 through 216, the Coupling Facility will

require connectivity to the same 9037 Sysplex Timer that

the systems in its Parallel Sysplex cluster are using for

time synchronization. If the ICF is on the same server as a

member of its Parallel Sysplex environment, no additional

connectivity is required, since the server already has

connectivity to the Sysplex Timer. However, when an ICF

is conﬁ gured on any z990 or z900 Models 2C1 through

216 which do not host any systems in the same Parallel

Sysplex cluster, it is necessary to attach the server to the

9037 Sysplex Timer.

z900 Turbo or z890/z990 Model with ICF

and non-Parallel Sysplex LPARs

z/OS

Non-Sysplex

LPARs

CF01

ICF

z/OS

CF02

ICF z/OS

IBM ^ z900

or z890/z990

Sysplex

LPARs

CF02

ICF

IBM ^ z900

or z890/z990

Sysplex

LPARs

New Connection to Sysplex Timer

ICB-3/ ICB-4 / ISC-3

ICB-3 / ICB-4/ ISC-3

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