Getting this?

kernel: ns-slapd: segfault at <ADDR> ip <ALPHA> sp <ALPHA> error 4 in libc-2.17.so

Check free memory (/var/log/dirsrv/slapd-MWS-MDS-XYZ/errors):

[root@idmipa04 slapd-MWS-MDS-XYZ]# cat errors|tail -n 30
[23/May/2020:16:33:18.519974074 -0400] – WARN – NSACLPlugin – acl_parse – The ACL target cn=casigningcert cert-pki-ca,cn=ca_renewal,cn=ipa,cn=etc,dc=mws,dc=mds,dc=xyz does not exist
[23/May/2020:16:33:18.522332851 -0400] – WARN – NSACLPlugin – acl_parse – The ACL target cn=casigningcert cert-pki-ca,cn=ca_renewal,cn=ipa,cn=etc,dc=mws,dc=mds,dc=xyz does not exist
[23/May/2020:16:33:18.759212393 -0400] – WARN – NSACLPlugin – acl_parse – The ACL target cn=automember rebuild membership,cn=tasks,cn=config does not exist
[23/May/2020:16:33:18.773571691 -0400] – ERR – cos-plugin – cos_dn_defs_cb – Skipping CoS Definition cn=Password Policy,cn=accounts,dc=mws,dc=mds,dc=xyz–no CoS Templates found, which should be added before the CoS Definition.
[23/May/2020:16:33:18.820082920 -0400] – NOTICE – NSMMReplicationPlugin – changelog program – _cl5ConstructRUV – Rebuilding the replication changelog RUV, this may take several minutes…
[23/May/2020:16:39:06.851785150 -0400] – ERR – memory allocator – malloc of 2152941454 bytes failed; OS error 12 (Cannot allocate memory)
The server has probably allocated all available virtual memory. To solve
this problem, make more virtual memory available to your server, or reduce
one or more of the following server configuration settings:
  nsslapd-cachesize        (Database Settings – Maximum entries in cache)
  nsslapd-cachememsize     (Database Settings – Memory available for cache)
  nsslapd-dbcachesize      (LDBM Plug-in Settings – Maximum cache size)
  nsslapd-import-cachesize (LDBM Plug-in Settings – Import cache size).
Can't recover; calling exit(1).

Regards,
TK