思路：首先出现问题肯定是看log，/var/log/zabbix/zabbix-server.log
案例1：
using configuration file: /etc/zabbix/zabbix_server.conf
…
[file:dbconfig.c,line:545] zbx_mem_malloc(): out of memory (requested 16 bytes)
[file:dbconfig.c,line:545] zbx_mem_malloc(): please increase CacheSize configuration parameter
通过日志中报错里已经很明确的提示了修复办法：please increase CacheSize configuration parameter
所以，我们就去zabbix_server.conf中找到CacheSize字段
### Option: CacheSize
# Size of configuration cache, in bytes.
# Shared memory size for storing host, item and trigger data.
#
# Mandatory: no
# Range: 128K-8G
# Default:
# CacheSize=8M
根据服务器配置情况，修改CacheSize
### Option: CacheSize
# Size of configuration cache, in bytes.
# Shared memory size for storing host, item and trigger data.
#
# Mandatory: no
# Range: 128K-8G
# Default:
CacheSize=2048M
最后，重启Zabbix Server即可
systemctl start zabbix-server