Zabbix Agent is not responding after upgrade to Zabbix 4.0

[mbleonardo]

Hello!

We've got a problem with Zorka after upgrading to Zabbix 4.0:

# zabbix_get -s SERVER -p 10055 -k 'zorka.jmx["java","java.lang:type=Runtime","Uptime"]'
zabbix_get [16172]: Timeout while executing operation

But, with telnet, it works:

#telnet SERVER 10055
Trying 10.70.2.24...
Connected to SERVER.
Escape character is '^]'.
zorka.jmx["java","java.lang:type=Runtime","Uptime"]
ZBXD33784774Connection closed by foreign host.

The same happens with Zorka Dev. version (1.90.4).

I think this might be a bug related to this:

Support for the plain text protocol has been dropped and a header is now mandatory. A header has been added to Zabbix get requests, Zabbix server/proxy passive check requests and frontend requests to Zabbix server. As a consequence, Zabbix agents that are older than version 1.4 are no longer supported. Also, messages from self-written senders will be rejected if the header is absent. Whereas previously Zabbix trappers would accept messages without headers as well as messages with headers, now they will only accept messages with protocol header.

https://www.zabbix.com/documentation/current/manual/installation/upgrade_notes_400

If it's not a bug, I would appreciate any help on debugging/solving this.

Thank you!

[jitlogic]

Zorka is using plaintext at this moment. There is preliminary TLS support implemented in 1.90.x (master branch) but not tested at all. I'll try this with Zabbix 4.0 and let you know in a few days.

[jitlogic]

Fixed in both master and v1-stable branches. Please fetch and compile branch you're interested in. Note that compiling v1-stable requires JDK6. Official releases will be published sometime in December.

[kkmaslowski]

@jitlogic I updated zorka to 1.0.17 and I still have the same problem (Timeout). Should I compile it from sources?
UPDATE: compiled from sources on jdk6. Everything works ok!

[jitlogic]

Yes, forgot to mention, sorry. Stable branch (1.0.18-SNAPSHOT) needs to be compiled. Development branch has been released meanwhile, so it is available in 1.90.6.