MODERATOR: Please close this thread. I was being stupid. 
Solution:
Zabbix agent (active) did NOT respond to the server. The only items that worked were ones that still were marked as Zabbix agent.
I set the HostName configuration item correctly instead of assuming that HostNameItem would do the trick, and after restarting the agent everything looks good.
----
TL;DR:
proc.num[processName.exe] on a Windows server does not feed data to the Zabbix server when the item is defined as an active one. In passive mode, it works just fine. Is this an expected behavior or have I encountered some sort of bug?
My scenario:
I have a number of Windows servers where I need to know that certain processes are running. zabbix_get -s serverName -k proc.num[processName.exe] returns 1.
A "Zabbix agent" item using proc.num[processName.exe] returns 1.
A "Zabbix agent (active)" item using proc.num[processName.exe] is marked with a green Enabled label (rather than Not Supported), but I still get no data from it (with the graph showing "No Data"). I have tried restarting the both the agent and the server processes.
I've changed the stock Windows Agent discovery items (disk and network items) to "Zabbix agent (active)", and receive data with no issues, so there doesn't seem to be anything preventing the agent from feeding the server with data per se.
I set the debug level to 4 and logged to a file, receiving the following lines related to these items:
3092:20160519:105048.527 for key [proc.num[processName.exe]] received value [1]
3092:20160519:105048.527 In process_value() key:'SPEDTDS
roc.num[processName.exe]' value:'1'
3092:20160519:105048.527 In send_buffer() host:'192.168.3.8' port:10051 entries:5/100
3092:20160519:105048.527 send_buffer() now:1463647848 lastsent:1463647845 now-lastsent:3 BufferSend:5; will not send now
3092:20160519:105048.527 End of send_buffer():SUCCEED
3092:20160519:105048.527 buffer: new element 5
3092:20160519:105048.527 End of process_value():SUCCEED
3092:20160519:105048.527 In need_meta_update() keyroc.num[ProcessName.exe]
3092:20160519:105048.527 End of need_meta_update():FAIL
So the agent obviously seems to catch the correct value for the number of processes, but for some reason doesn't pass it on to the server.
Do you have any idea what the next troubleshooting step would be from where I am now?
Solution:
Zabbix agent (active) did NOT respond to the server. The only items that worked were ones that still were marked as Zabbix agent.
I set the HostName configuration item correctly instead of assuming that HostNameItem would do the trick, and after restarting the agent everything looks good.
----
TL;DR:
proc.num[processName.exe] on a Windows server does not feed data to the Zabbix server when the item is defined as an active one. In passive mode, it works just fine. Is this an expected behavior or have I encountered some sort of bug?
My scenario:
I have a number of Windows servers where I need to know that certain processes are running. zabbix_get -s serverName -k proc.num[processName.exe] returns 1.
A "Zabbix agent" item using proc.num[processName.exe] returns 1.
A "Zabbix agent (active)" item using proc.num[processName.exe] is marked with a green Enabled label (rather than Not Supported), but I still get no data from it (with the graph showing "No Data"). I have tried restarting the both the agent and the server processes.
I've changed the stock Windows Agent discovery items (disk and network items) to "Zabbix agent (active)", and receive data with no issues, so there doesn't seem to be anything preventing the agent from feeding the server with data per se.
I set the debug level to 4 and logged to a file, receiving the following lines related to these items:
3092:20160519:105048.527 for key [proc.num[processName.exe]] received value [1]
3092:20160519:105048.527 In process_value() key:'SPEDTDS
roc.num[processName.exe]' value:'1'3092:20160519:105048.527 In send_buffer() host:'192.168.3.8' port:10051 entries:5/100
3092:20160519:105048.527 send_buffer() now:1463647848 lastsent:1463647845 now-lastsent:3 BufferSend:5; will not send now
3092:20160519:105048.527 End of send_buffer():SUCCEED
3092:20160519:105048.527 buffer: new element 5
3092:20160519:105048.527 End of process_value():SUCCEED
3092:20160519:105048.527 In need_meta_update() key
roc.num[ProcessName.exe]3092:20160519:105048.527 End of need_meta_update():FAIL
So the agent obviously seems to catch the correct value for the number of processes, but for some reason doesn't pass it on to the server.
Do you have any idea what the next troubleshooting step would be from where I am now?