You must identify a primary CMAS:
To do this, you must change the CICS® system definition to identify the CMAS to which the CICS system normally connects. This primary CMAS is used to assist in balancing real-time analysis processing. That is, when the first CMAS involved in managing a CICSplex is started, it monitors all CICS systems comprising the CICSplex. As subsequent CMASs start, they begin monitoring the systems for which they are the primary CMAS. Over time, this helps to balance monitoring across all of the CMASs involved in the CICSplex.
To do this, you can identify a primary CMAS and one or more secondary CMASs.
When you identify one primary CMAS, all CICSplex-level processing occurs within that CMAS. As an alternative, you can partition the CICSplex at the CMAS level. That is, each CMAS participating in the management of a CICSplex may process one or more analysis point specifications. This mode of operation allows greater flexibility when managing a CICSplex being managed by multiple CMASs. Note that this partitioning does not preclude any CMAS from acting on CICS systems attached to other CMASs.