Getting Started

Nuclei start "open" to new users. To modify the status of nuclei throughout the cluster, read about the ADACOM command SN - Set Nucleus Status.

NUCIDs and DBIDs must have unique values in the range 1 through 65000.

This document covers the following topics:


ADACOM Starts

The ADACOM task must be run to set up the Adabas Parallel Services cluster environment before any cluster nucleus is started. ADACOM must be maintained in operation until the last cluster nucleus it manages is terminated.

A common storage area is allocated for maintaining information about active users and the nuclei to which they are assigned.

First Cluster Nucleus Starts

When a nucleus with a nonzero NUCID starts, it determines whether its ADACOM is running. If not, it will not start.

If its ADACOM is running, the first nucleus

  • builds an ID table header (IDTH) element for the DBID, which marks the database as a cluster database. The DBID must be unique across the image in the range 1-65000. If LOCAL=NO is in effect, the DBID must be unique across all Entire Net-Work target IDs.

  • sets an ID table entry (IDTE) to its NUCID in the nucleus table in CSA space to indicate that it is active. The NUCID must be unique across the image in the range 1-65000.

Additional Cluster Nuclei

If another nucleus for the same Adabas Parallel Services cluster comes up, the global DBID is already set and it sets its nucleus IDTE equivalent to its NUCID.