Gaps only in graphs of data collecting via Zabbix agent

[wyang]

Standalone Zabbix server has been working in our environment for 3 years. Recently, the following issues appear
- Gaps in and only in graphs of data collecting via Zabbix agents
-- No gap in graphs of data collection via SNMP agents
- Alarms "Zabbix agent on <host name> is unreachable for 5 minutes" are frequently triggered and cleared.
-- TCP connections to server port and TCP connections to agent ports are OK.
- Zabbix server web interface intermittently shows "zabbix server is not running:the information displayed may not be current".

Any suggestions to resolve/debug this issue?

Thanks and regards.

[volter]

Go through these two charts: http://zabbix.org/wiki/Troubleshooti..._debug_that.3F

[wyang]

Thanks volter. Greatly appreciated for your time and help.

The issue is resolved with the reference of https://www.zabbix.com/forum/showpos...3&postcount=12

Thanks you all for your help!