Clustering with SNMP Proxy

[victor]

Hi!

I plan 1.0.8 to be mostly a bugfix release (plus custom SNMP port feature), and if everything will go as expected, I'll will release it in a week.

Best regards,
Victor

[Sumit Pandya]

I installed 1.0.8 and configure a node with custom port number. I see that NetXMS still not able to do data collection over SNMP custom ports. As soon as I add node NetXMS send SNMP-Query for 1.3.6.1.2.1.1.2.0 (4 retransmission with V1 and 4 retransmission with V2c) and 1.3.6.1.4.1.2620.1.1.10.0 (4 retransmission with V1 and no V2c)
Then I went into node-properties and selected SNMP UDP Port to 1161 under "Communication" tab. Further I added my RADIUS-OID i.e. .1.3.6.1.2.1.67.1.1.1.1.5 with proper custom SNMP port selection. Now I could see snmp requests (custom port) for OID .1.3.6.1.2.1.67.1.1.1.1.5  and 1.3.6.1.2.1.1.2.0 into Wireshark. I could see proper response from my agent as well.
Note that my SNMP Agent support only RADIUS-MIB and it sends "noSuchName" error-response to unsupported OIDs like 1.3.6.1.2.1.1.2.0 and 1.3.6.1.4.1.2620.1.1.10.0. My agent is behind firewall and ping is also blocked.
I think NetXMS is dependent on response for those 2 basic OIDs i.e. 1.3.6.1.2.1.1.2.0 and 1.3.6.1.4.1.2620.1.1.10.0.
I see some UDP packets for destination-port 260. Why that traffic is seen/originated?
Please advise on how to configure a node with custom SNMP Port.

[Sumit Pandya]

In the last try, i recreated node with "Unmanaged object". I first configured everything and disabled NetXMS agent, ICMP ping, status poll, configuration poll, routing table poll, ifXTable for pooling interfacec into "Polling" tab of properties. Then I started "Manage" this node. I'm happy to see NetXMS working properly. Now SNMP-Query with my OID is only traffic b/w NetXMS and our RADIUS server.

Victor, for your kind attention I'd like to see a graph with combined (sum) value from 2 (or more) similar nodes. As you know I've 2 machines running same software and there is a load-balancer. There is no "official" clustering but it can be seen as server-farm. Please guide me how to achieve that?

[victor]

Hi!

During configuration poll, NetXMS server tries to detect SNMP agent by sending requests for OID .1.3.6.1.2.1.1.2.0. If agent present, but does not respond to this request, it is considered as unavailable. Later during data collection, if node is not marked as SNMP-capable, SNMP DCIs not collected - the only exception is DCIs with custom SNMP ports. If you SNMP agent which does not support standard MIB-2 OIDs, then better way is to disable SNMP for given node and set port number explicitly for each SNMP DCI.

SNMP requests to port 260 generated during configuration poll in attempt to detect Check Point SNMP agent.

Best regards,
Victor

[Sumit Pandya]

Victor,
    Any though/suggestion for combined/sum graph?

[victor]

Hi!

You can use transformation scripts to get values from different nodes and sum them up to value of current DCI. For example, if you have DCIs named "Param1" on nodes node1 and node2, you can create the following transformation script on node1 to add up value from node2:

node2 = FindNodeObject($node, "node2");
value = GetDCIValue(node2, FindDCIByDescription(node2, "Param1"));
return $1 + value;

See also the following topics:
https://www.netxms.org/forum/configuration/findnodeobject-not-working-(for-me)/
https://www.netxms.org/forum/configuration/nxsl-and-dci/

Please also note that if you are using server older than 1.0.8, you must explicitly define main function in your script, i.e.

sub main()
{
   node2 = FindNodeObject($node, "node2");
   value = GetDCIValue(node2, FindDCIByDescription(node2, "Param1"));
   return $1 + value;
}

Best regards,
Victor

[Sumit Pandya]

Dear Victor, The script you shared did not worked. I tried to "Test" above transformation with Test value = 2(random), I get error "Error 14 in line 2: Left argument of -> must be a reference to object". I further added a check
 if (node2 == null)
      return 0;  // No such node or access denied

and surprisingly I get this "0" returned. Please note that my nodes are part of cluster. Is that could be limitation?

Using the approach you suggest, I may loose information of my one node. I just wonder if you can have some push method from scripting. Can I create a dummy node, define data collection with origion "Push Agent". Then define a schedule to run every minute "1 * * * *". Finally do something like below into Transformation?

node1 = FindNodeObject($node, "system-1");
value1 = GetDCIValue(node1, FindDCIByDescription(node1, "Auth-Req"));
node2 = FindNodeObject($node, "system-2");
value2 = GetDCIValue(node2, FindDCIByDescription(node2, "Auth-Req"));
return value1 + value2;

I'd even fine if database triger level of twick can be done as some very advance level.

[victor]

@sumit-pandya said in Clustering with SNMP Proxy:

Dear Victor, The script you shared did not worked. I tried to "Test" above transformation with Test value = 2(random), I get error "Error 14 in line 2: Left argument of -> must be a reference to object". I further added a check
 if (node2 == null)
      return 0;   // No such node or access denied

and surprisingly I get this "0" returned. Please note that my nodes are part of cluster. Is that could be limitation?

Did you set trusted nodes as described here: https://www.netxms.org/forum/configuration/nxsl-and-dci/msg4633/#msg4633? Most likely it's an access control issue.

@sumit-pandya said in Clustering with SNMP Proxy:

Using the approach you suggest, I may loose information of my one node. I just wonder if you can have some push method from scripting. Can I create a dummy node, define data collection with origion "Push Agent". Then define a schedule to run every minute "1 * * * *". Finally do something like below into Transformation?

node1 = FindNodeObject($node, "system-1");
value1 = GetDCIValue(node1, FindDCIByDescription(node1, "Auth-Req"));
node2 = FindNodeObject($node, "system-2");
value2 = GetDCIValue(node2, FindDCIByDescription(node2, "Auth-Req"));
return value1 + value2;

I'd even fine if database triger level of twick can be done as some very advance level.

You can create additional DCI with source "Internal" and name "Dummy" (of course description can be any). It will always have value of 0, and you can schedule it like any other DCI and use transformation script to get values from two "real" DCIs and sum them.

Best regards,
Victor

[Sumit Pandya]

Script testing work but it doesnot gets scheduled. after some time DCI status get changed to "Not Supported". I did tried with both defaulting Interval to 60 seconds as well using advanced schedule "1 * * * *". Please guide me further.

About all other problems I think that databases changes takes very long time to get reflected into other modules/components. I request you to check commit type of activity at some configuration change activity. I suspect same could be causing database curruption while shutdown!!!

[victor]

Could you please send me screenshots of your DCI configuration?

Best regards,
Victor

[Sumit Pandya]

Find attached screen. Please note that Transformation script returns proper result while testing. Below is script for your quick reference (Though it is not required)
node1 = FindNodeObject($node, "SSTLDel52");
value1 = GetDCIValue(node1, FindDCIByDescription(node1, "AuthReq"));
node2 = FindNodeObject($node, "SSTLDel54");
value2 = GetDCIValue(node2, FindDCIByDescription(node2, "AuthReq"));
return value1 + value2;

After posting, I let "Parameter" name to be remained "Dummy". Now I see I can get proper values automatically by schedule. Cheers.

On another nodes: I followed your instruction about "Cluster node disapper" with patch. Now my nodes remains after restart.

I hope you have enough BUG registrar generate. Though all of my problems got resolved by workarounds

---

[victor]

Yes, it must be named "Dummy". This is what I wrote in my previous message:

@victor said in Clustering with SNMP Proxy:

You can create additional DCI with source "Internal" and name "Dummy" (of course description can be any).

You can change description of the DCI, but not the name. Description is a free form text intended to be read and understand by humans, but name is a parameter's identifier understandable by server and/or agents. "Internal" origin means that values for these parameters generated by NetXMS serer itself, without asking any external entities. One of supported internal parameters is named "Dummy", and it always returns 0 when polled for value. It was added specifically for providing "ticks" for calculated DCIs.

So it is not a "workaround", it's just correct system configuration

Best regards,
Victor

[Sumit Pandya]

@victor said in Clustering with SNMP Proxy:

Yes, it must be named "Dummy". This is what I wrote in my previous message:

@victor said in Clustering with SNMP Proxy:

You can create additional DCI with source "Internal" and name "Dummy" (of course description can be any).

My mistake to overlook that "Quotation"  though "Quotation" is my practice as well.

@victor said in Clustering with SNMP Proxy:

So it is not a "workaround", it's just correct system configuration

I'm indded sorry for that unusual term. However I's not only pointing about this "Dummy" problem. I've co-related all my experience with NetXMS, like Cluster node disapper, OS hang without n/w, etc. For this "Dummy", if you cannot allow any other name then can't it make some select-only/drop-down type input there?

Finally Yes, this thread can be closed but this has something to go into Mantis

[Sumit Pandya]

Can I create DCI for dummy summary node with help of Array as below?
array monitornodes;
monitornodes = {"system-1" , "system-2", "system-3"};
summary=0;
for (i=1; monitornodes[i] != NULL ; i++)
{
  inode = FindNodeObject($node, monitornodes[i]);
  ivalue = GetDCIValue(inode, FindDCIByDescription(inode, "TotalAuth"));
  summary = summary + ivalue;
}
return summary;

I see array initialization is not been supported as above syntax. However I get success with below syntax
array monitornodes;
monitornodes[1] = "system-1";
monitornodes[2] = "system-2";
monitornodes[2] = "system-3";

My point of asking is primary about array initialization syntax.

[victor]

Hi!

The only possible initialization of array is like

monitornodes[1] = "system-1";
monitornodes[2] = "system-2";
monitornodes[2] = "system-3";

I like the idea of having array initializers, I will add it to NXSL. Also, your script has an error if for loop condition - it should be monitornodes[i] != NULL, not monitornodes != NULL. So, correct version of the script should looks like this:

array monitornodes;

monitornodes[1] = "system-1";
monitornodes[2] = "system-2";
monitornodes[2] = "system-3";

summary=0;
for (i=1; monitornodes[i] != NULL ; i++)
{
  inode = FindNodeObject($node, monitornodes[i]);
  ivalue = GetDCIValue(inode, FindDCIByDescription(inode, "TotalAuth"));
  summary += ivalue;
}

return summary;

Best regards,
Victor