Writing Active Zabbix Agent, what to send in “clock” and “ns”

[allardkrings]

Hello,

I am writing my own zabbix-agent for z/OS in REXX

Everything works fine, the agent gets the active checks from the zabbix-server, the agent sends back the response, the zabbix server processes my response,

however I am not sure what to put in the fields “clock” and “ns”

Below is the example of the message protocol from the Zabbix documentation:


<HEADER><DATALEN>
{ "request":"agent data",
"data":[
{
"host":"<hostname>",
"key":"agent.version",
"value":"2.4.0",
"clock":1400675595,
"ns:6808644
}
],
"clock": 1400675595,
"ns": 78211329
}

Anybody can explain the meaning of these fields is?

Thanks in advance!

Kind regards

Allard

[dimir]

{
  "request":"agent data",
  "data":[
    {
      "host":"<hostname>",
      "key":"agent.version",
      "value":"2.4.0",
      "clock":1400675595, <-- value timestamp, when it was collected, seconds
      "ns:6808644         <-- value timestamp, when it was collected, nanoseconds
    }
  ],
  "clock": 1400675595, <-- timestamp of the whole request, when it was generated, seconds
  "ns": 78211329       <-- timestamp of the whole request, when it was generated, nanoseconds
}

[allardkrings]

Hello Dimir,

thanks a lot for your quick response!

Could you give me more information on the timestamp ? Relative to what moment should te values be calculated?

Is it UNIX standard Epoch?

If I take that value for today and now i get: “clock”: 1618073802
Or in nanoseconds : “ns”: 1618073802000000000

both are much longer than the example

Kind regards

Allard

[dimir]

In the "agent data" packet you have an array of metrics + timestamp of the packet itself. When an agent is collecting a metric it remembers the timestamp when it was collected, thus each metric has its pair - "value + timestamp of the value".

When collected data is sent to server/proxy it's combined in one request as an array. When this request is generated it is assigned the creation timestamp too.

Each "timestamp" in Zabbix is represented as pair "clock+ns". As to the "clock", yes, it's just the unix standard timestamp aka Epoch. The nanoseconds is additional fraction of the following second, i. e. it's the value from 0 to 999999999. Nanoseconds make sense for rare cases when the item can receive more than one value in a second. If you are sure that's not your case you can always set nanosecond to 0:

{
  "request":"agent data",
  "data":[
    {
      "host":"<hostname>",
      "key":"agent.version",
      "value":"2.4.0",
      "clock":1400675592
      "ns":0
    },
    {
      "host":"<hostname>",
      "key":"agent.hostname",
      "value":"webserver",
      "clock":1400675590
      "ns":0
    }
  ],
  "clock": 1400675595
  "ns": 0
}