Large amounts of password updates affect on LID database ACF2
Article ID: 197827
Updated On:
Products
Issue/Introduction
Planning to make a change that will cause potentially maybe hundred thousands ACF2 users to change password during A day. Would there be reason to suspect that ACF2 will have performance issues during this time due to high amounts of password changes.
Because of VSAMs limit to 4GB and need to relatively often reorganize the data set to compress it we are concerned that this large amount of password changes can lead to issues specifically the need to reorganize the data set quickly again.
Do these concerns have any basis.
Environment
Release : 16.0
Component : CA ACF2 for z/OS
Resolution
Having users change their passwords/passphrases will not affect the performance of the systems unless all users change at the same exact time.
When VSAM is called to delete or replace a record, it flags the space as deleted and writes a new record. However, the deleted or replaced record is not actually deleted, but is only flagged as deleted, and continues to consume space. The accumulation of these flagged records results in less available free space within a VSAM data cluster. To delete these flagged records completely, periodically run the REORG command on all VSAM clusters.
Having old passwords expired and users inserting new passwords should not affect the lid database or the need for a re-org.
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