Zabbix 5.4 crashing with backtrace

[dyasny]

I've installed a fresh 5.4 on CentOS8 today, after some configuration it started crashing with the following in the log:

91713:20210706:210944.787 Starting Zabbix Server. Zabbix 5.4.2 (revision 4c8f9aabe1).
91713:20210706:210944.787 ****** Enabled features ******
91713:20210706:210944.788 SNMP monitoring: YES
91713:20210706:210944.788 IPMI monitoring: YES
91713:20210706:210944.788 Web monitoring: YES
91713:20210706:210944.788 VMware monitoring: YES
91713:20210706:210944.788 SMTP authentication: YES
91713:20210706:210944.788 ODBC: YES
91713:20210706:210944.788 SSH support: YES
91713:20210706:210944.788 IPv6 support: YES
91713:20210706:210944.788 TLS support: YES
91713:20210706:210944.788 ******************************
91713:20210706:210944.788 using configuration file: /etc/zabbix/zabbix_server.conf
91713:20210706:210944.798 current database version (mandatory/optional): 05040000/05040000
91713:20210706:210944.798 required mandatory version: 05040000
91713:20210706:210944.811 server #0 started [main process]
91714:20210706:210944.812 server #1 started [configuration syncer #1]
91714:20210706:210945.036 __mem_malloc: skipped 0 asked 256 skip_min 18446744073709551615 skip_max 0
91714:20210706:210945.036 [file:dbconfig.c,line:102] __zbx_mem_malloc(): out of memory (requested 256 bytes)
91714:20210706:210945.036 [file:dbconfig.c,line:102] __zbx_mem_malloc(): please increase CacheSize configuration parameter
91714:20210706:210945.036 === memory statistics for configuration cache ===
91714:20210706:210945.036 free chunks of size 24 bytes: 145
91714:20210706:210945.036 free chunks of size 32 bytes: 54
91714:20210706:210945.036 free chunks of size 40 bytes: 4
91714:20210706:210945.036 free chunks of size 48 bytes: 3
91714:20210706:210945.036 free chunks of size 56 bytes: 5
91714:20210706:210945.036 free chunks of size 232 bytes: 1
91714:20210706:210945.036 min chunk size: 24 bytes
91714:20210706:210945.036 max chunk size: 232 bytes
91714:20210706:210945.036 memory of total size 7203864 bytes fragmented into 74024 chunks
91714:20210706:210945.036 of those, 6024 bytes are in 212 free chunks
91714:20210706:210945.036 of those, 7197840 bytes are in 73812 used chunks
91714:20210706:210945.036 of those, 1184368 bytes are used by allocation overhead
91714:20210706:210945.036 ================================
91714:20210706:210945.036 === Backtrace: ===
91714:20210706:210945.037 13: /usr/sbin/zabbix_server: configuration syncer [syncing configuration](zbx_backtrace+0x3f) [0x557bdd177069]
91714:20210706:210945.037 12: /usr/sbin/zabbix_server: configuration syncer [syncing configuration](__zbx_mem_malloc+0x180) [0x557bdd171cf4]
91714:20210706:210945.037 11: /usr/sbin/zabbix_server: configuration syncer [syncing configuration](+0x199279) [0x557bdd0fd279]
91714:20210706:210945.037 10: /usr/sbin/zabbix_server: configuration syncer [syncing configuration](+0x21fe14) [0x557bdd183e14]
91714:20210706:210945.037 9: /usr/sbin/zabbix_server: configuration syncer [syncing configuration](zbx_vector_ptr_append+0x1c) [0x557bdd183fcf]
91714:20210706:210945.037 8: /usr/sbin/zabbix_server: configuration syncer [syncing configuration](+0x1a605b) [0x557bdd10a05b]
91714:20210706:210945.037 7: /usr/sbin/zabbix_server: configuration syncer [syncing configuration](DCsync_configuration+0xc37) [0x557bdd10ba5c]
91714:20210706:210945.037 6: /usr/sbin/zabbix_server: configuration syncer [syncing configuration](dbconfig_thread+0x122) [0x557bdcfca5a8]
91714:20210706:210945.037 5: /usr/sbin/zabbix_server: configuration syncer [syncing configuration](zbx_thread_start+0x37) [0x557bdd186fba]
91714:20210706:210945.037 4: /usr/sbin/zabbix_server: configuration syncer [syncing configuration](MAIN_ZABBIX_ENTRY+0xb39) [0x557bdcfb8bdd]
91714:20210706:210945.037 3: /usr/sbin/zabbix_server: configuration syncer [syncing configuration](daemon_start+0x2ff) [0x557bdd176c93]
91714:20210706:210945.037 2: /usr/sbin/zabbix_server: configuration syncer [syncing configuration](main+0x2f6) [0x557bdcfb7fd0]
91714:20210706:210945.037 1: /lib64/libc.so.6(__libc_start_main+0xf3) [0x7f5fd2143493]
91714:20210706:210945.037 0: /usr/sbin/zabbix_server: configuration syncer [syncing configuration](_start+0x2e) [0x557bdcfb6ece]
91713:20210706:210945.039 One child process died (PID:91714,exitcode/signal:1). Exiting ...
91713:20210706:210945.040 syncing trend data...
91713:20210706:210945.041 syncing trend data done
91713:20210706:210945.041 Zabbix Server stopped. Zabbix 5.4.2 (revision 4c8f9aabe1).

[dyasny]

This was the crux:
91714:20210706:210945.036 __mem_malloc: skipped 0 asked 256 skip_min 18446744073709551615 skip_max 0
91714:20210706:210945.036 [file:dbconfig.c,line:102] __zbx_mem_malloc(): out of memory (requested 256 bytes)
91714:20210706:210945.036 [file:dbconfig.c,line:102] __zbx_mem_malloc(): please increase CacheSize configuration parameter

Increased CacheSize from 8M to 1G and everything seems to be working again