Description of problem:

389-ds-base crash, possible corrupted entry cache, and possible regression from
https://github.com/389ds/389-ds-base/issues/5262
https://bugzilla.redhat.com/show_bug.cgi?id=2051476 (high contention in find_entry_internal_dn on mixed load) 


Version-Release number of selected component (if applicable):

RHEL-8.8 with RHDS-11.6 ( unsupported combination )

389-ds-base.x86_64-1.4.3.29-3.module+el8dsrv+14615+a86efbbf
redhat-release-8.8-0.8.el8.x86_64


How reproducible:
N/A

Steps to Reproduce:
1. N/A
2.
3.

Actual results:

appears to happen right after a possible DB_DEADLOCK:

Jul  4 15:04:02 edited ns-slapd[1827]: [04/Jul/2023:15:04:02.821943215 +0200] - WARN - keys2idl - received NULL idl from index_read_ext_allids, treating as empty set
Jul  4 15:04:02 edited ns-slapd[1827]: [04/Jul/2023:15:04:02.822747769 +0200] - WARN - keys2idl - this is probably a bug that should be reported
Jul  4 15:04:02 edited ns-slapd[1827]: [04/Jul/2023:15:04:02.823265165 +0200] - ERR - build_candidate_list - Database error -30993

crashing thread:

#1  0x00007f3089b93e95 PR_ExitMonitor (libnspr4.so)#012
#2  0x00007f307f08e591 modify_term (libback-ldbm.so)#012
#3  0x00007f307f073b41 ldbm_back_add (libback-ldbm.so)#012
#4  0x00007f308d0ff878 op_shared_add (libslapd.so.0)#012
#5  0x00007f308d100917 do_add (libslapd.so.0)#012
#6  0x0000561d000d23c1 connection_threadmain (ns-slapd)#012
#7  0x00007f3089b99968 _pt_root (libnspr4.so)#012
#8  0x00007f30895341ca start_thread (libpthread.so.0)#012
#9  0x00007f308b7e7e73 __clone (libc.so.6)#012#012Stack trace of thread 2437:#012


Expected results:


Additional info:

came from an environment configured in a non tested combination of versions:
RHEL-8.8 with RHDS-11.6 ( unsupported combination )
389-ds-base.x86_64-1.4.3.29-3.module+el8dsrv+14615+a86efbbf
redhat-release-8.8-0.8.el8.x86_64

references:

https://access.redhat.com/documentation/en-us/red_hat_directory_server/11/html/release_notes/index
RHDS-11.5 RHEL-8.6 - https://access.redhat.com/documentation/en-us/red_hat_directory_server/11/html/release_notes/directory-server-11.5#supported-platforms-for-directory-server-11.5

https://access.redhat.com/downloads/content/rhel---8/x86_64/8669/389-ds-base/1.4.3.29-3.module+el8dsrv+14615+a86efbbf/x86_64/fd431d51/package-changelog

this combination may possibly work fine, but these are not the exact bits Red Hat test, release and support, and we have a crash report.