how to know the process status of WinCC OA console on slave node

[winccoa_2020]

Hello

I have one master node and slave node, both of them will launch a process named WCCOATest (the process WCCOATest will get WinCC OA DB data through the C# API and send them to external programs)

The process WCCOATest works as primary/secondary role on master/slave node.
We have to monitor the alive status of WCCOATest on both master and slave nodes and write their alive status to
WinCC OA DB, so that the WCCOATest on each node with know the alive status other WCCOATest on the other node and then decide to do primary/secondary role switch.

We found an issue that it can't write the alive status for the WCCOATest on the slave node. It can only write the alive status for WCCOATest on master node, as the WinCC OA pmon on the master node can't know the alive status of WCCOATest on the slave node. So is there any way that we can write the alive status on the slave node?

[winccoa_2020]

I saw there is a pmon_query function in pmon.ctl script.
I use below code:

pmon_query("username#password#MGRLIST:STATI", "<hostname>", 4999, res, true, true);

If the <hostname> is local host, I can get the all status of processes in local WinCC OA console.
But if I use the another node's as hostname, it always print out the TcpOpen timeout issue....

So will PMon port 4999 can only support local access?

How can I access the PMon of the other servers?


(BTW, I've enabled the port 4999 in Windows firewall setting on both Master/Salver node)

[dbindernagel]

From the help:

Code: Select all

Pmon only listens to "localhost" by default. This means that you can reach the pmon only via the localhost. Use the config entry localAddress to change the network address of a server.

Code: Select all

localAddress
Type: string
Default: 
Range: 

localAddress allows to specify the local network address of a server. By default a server can be reached via all local addresses. An exception is the Pmon, which by default listens to "localhost" and is reachable from the same computer only and not from others. localAddress allows to specify via which local IP addresses a server can be reeached, e.g. from the loopback address only (localhost or 127.0.0.1) or via a specific network card. Valid entries are "" for all addresses, "0.0.0.0" for all IPv4 addresses, "::" for all IPv6 addresses, "127.0.0.1" or "localhost for IPv4 loopback, "::1" for IPv6 loopback address, or every other local IP address.

[winccoa_2020]

Hi, Dbindernagel

Thanks for your info.
Do you mean that it's not possible to get pmon info from other nodes?

[gschijndel]

We have to monitor the alive status of WCCOATest on both master and slave nodes and write their alive status to
WinCC OA DB, so that the WCCOATest on each node with know the alive status other WCCOATest on the other node and then decide to do primary/secondary role switch.

We found an issue that it can't write the alive status for the WCCOATest on the slave node. It can only write the alive status for WCCOATest on master node, as the WinCC OA pmon on the master node can't know the alive status of WCCOATest on the slave node. So is there any way that we can write the alive status on the slave node?

In order to allow the passive host to write status values, you have to configure the system to allow writing of these values by the passive host. This can be done with the 'fwdDpType' entry in the 'config.redu' of your (sub)project.
More information regarding this can be found in the documentation under: Special functions -> Redundancy -> Configuration files for redundancy.

Do you mean that it's not possible to get pmon info from other nodes?

By setting the 'localAddress' config entry for the pmon it is possible to get pmon info from other nodes. For security reasons this access has been limited, so it should be carefully considered if it is really necessary to change this.

[winccoa_2020]

Thanks for your comments.

For my project, both master/salve node run the same config file. I didn't see config.redu at all.
We set data and event with value "<master_node>$<slave_node>" in the config file and then the redundancy works.
So how I can configure the system to allow writing values on slave node without configu.redu file?


For 'localAddress', I need to set it to '0.0.0.0' as for valid entries in config file. Is that correct?

[leoknipp]

If a manager running on/connected the passive server of a redundant must be able to set a datapoint element you have to define the fwdDp/fwdDpType entries.
The entries can be set in the config or config.redu file.
There is no other possibility to allow writing of values on the passive server.

For the localAddress entry please refer to the documentation mentioned in a posting above.
When you want to allow all hosts to connect you have to set the entry localAddress = ""

Best Regards
Leopold Knipp
Senior Support Specialist

[winccoa_2020]

@leoknipp and gschijndel

Thanks for your help.
After adding the tags with fwdDp in config file. The value on slave node can be updated in WinCC OA DB now.