JSON Message Length Problem with Zabbix 3.2

[estein]

All,

We have been using Zabbix 2.2 for years and finally updated to 3.2, and now we are having issues with the JSON length that we try to send to Zabbix. I haven't been able to determine but what is the maximum length that one can send to Zabbix through java code. Below is sample java code I use to send a json message along with th esample message.

Excuse the lack of declarations in the code. This forum apparently doesn't like multiple equal declarations even within code blocks.

Sample Code:

	
        Socket zabbixSocket = new Socket(zabbixServer, port);    
        zabbixSocket.setSoTimeout(30000);
            
        out   zabbixSocket.getOutputStream();
        is   new DataInputStream(zabbixSocket.getInputStream());
       

	int length = data.length;

        out.write(new byte[] { 'Z', 'B', 'X', 'D', '\1',
                (byte) (length & 0xFF), (byte) ((length & 0x00FF) >> 8),
                (byte) ((length & 0x0000FF) >> 16),
                (byte) ((length & 0x000000FF) >> 24), '\0', '\0', '\0', '\0' });

        out.write(data);
        out.flush();


        is.read
...

Sample Message:

"request":"sender data",
"data":[
{
"host":"myserver.abc.com",
"key":"tnail-avail",
"value":"1"
},
{
"host":"myserver.abc.com",
"key":"tnail-valid",
"value":"1"
},
{
"host":"myserver.abc.com",
"key":"tnail-ms",
"value":"0"
},
{
"host":"myserver.abc.com",
"key":"tnail-version",
"value":"7.3.0000"
}]

Oddly enough, if I remove the last key/value entry, then Zabbix receives it perfectly fine regardless of whether it's Zabbix 2.2 or 3.2. So there is clearly a limiting factor there but I am unsure what it is exactly.


We need to do this through java code and not the standalone utility. So if someone provide a better method or a wait to increase the Json limit without decompiling/recompiling server code, I would really appreciate it.

Bear in mind there are hundred of these agents running and recording data, so we need a solution that is easy to distribute.

[glebs.ivanovskis]

I guess you are missing top-level {} around your JSON. And maybe you are miscalculating message length, validation is stricter since 3.0. What is in response of Zabbix server? Have you checked log file for errors?

[estein]

The JSON is fine. I just forgot some brackets in the posting to this forum.

Also, I forgot to indicate that

data = jsonString.getBytes();

The log reports the following:

371:20170105:152004.579 Message from x.x.x.x is longer than expected xxx bytes. Message ignored.

And the Zabbix socket input stream is empty as a result of the message being discarded.

How is the validation determined? What is the maximum byte length allowed? Can this be changed somewhere?

[estein]

RESOLVED: Json Message Length issue

Looks the problem was how we were building the byte message. Needed SHIFTRIGHT and then AND

 out.write(new byte[] { 
        		'Z', 'B', 'X', 'D', '\1',
                (byte) ((length >> 0)  & 0xFF), 
                (byte) ((length >> 8)  & 0x00FF),
                (byte) ((length >> 16) & 0x0000FF),
                (byte) ((length >> 24) & 0x000000FF), 
                '\0', '\0', '\0', '\0' });

[wang.hy8166]

mark for:
293:20181106:000531.093 Message from 172.18.0.1 is shorter than expected 12435439 bytes. Message ignored.