Efficiency with many SNMP devices

[AntonioSousa]

I have a v2 extension, SNMP, that has around 1500 devices. Initially, most of them were created in blocks with 100 devices.

The configurations are dynamic though, and being API driven. So I'm getting "fragmented" monitoring configurations. And I'm creating new ones.

I'm not sure if using blocks with 100 devices turns out to be more efficient or not. But given what is said in https://www.dynatrace.com/support/help/extend-dynatrace/extensions20/extensions-concepts

You can define up to 20,000 devices for a single monitoring configuration. Configurations are split into buckets, with a default size of 100 devices per bucket. Each bucket of devices is polled independently as a separate process on one of the ActiveGates in a group. This feature is automatically enabled for WMI, Prometheus, SNMP, and SQL extensions, while for other types of extensions, its activation depends on the specific extension.

it seems that Dynatrace gets my fragmented configurations, and runs them in buckets of 100 devices, and I need not worry?

BTW, when we scale usage of SNMP monitoring, what other efficiency measures are appropriate?

[Mike_L · Accepted solution]

You indeed do not need to worry anymore. Dynatrace automatically splitting up a large monitoring configuration into smaller ones and distributing them onto the AGs makes for a much easier set up.

Efficiency measures - Making sure that the AG is close to the device so it's not having a lot of network latency and dropped packages. The SNMP datasource scales quite well both horizontally and vertically, giving you many options on how to get more devices monitored.

[AntonioSousa]

@Mike_L,

Thanks for your input! I really feel that we are able to monitor large setups with relatively few AG resources. We do have to open some gates, but I believe they are there to protect against bad setups.

[mferstl]

Hi,
I am testing SNMP for Generic Network devices as well.
Using 1 Active Gate at the moment.

When i add 1600 devices, SNMP polling seems just to stop working. I waited longer than 1 hour, but the logs kept empty.

After dropping to 200 devices only i get this alert:
Failed to assign monitoring configuration to ActiveGate. Reason: INVALID_CONFIG_ERROR:Invalid configuration: Activation configuration contains too many SNMP devices: 155; [status code=32];

Seems the limit is 100

Failed to assign monitoring configuration to ActiveGate. Reason: INVALID_CONFIG_ERROR:Invalid configuration: Activation configuration contains too many SNMP devices: 102; [status code=32];

below 100 devices it works

[AntonioSousa]

@mferstl,

Yes, there is a limit of 100 per monitoring configuration:

https://docs.dynatrace.com/docs/extend-dynatrace/extensions20/extensions-concepts

[Mike_L]

SNMP extensions are remote, and fall under the next row in that table. The limit is 20.000. I'd go with a support ticket if it's failing.

[AntonioSousa]

@Mike_L,

I too have the 100 limit happened in a customer, some 4 weeks ago. Message was the same: "Failed to assign monitoring configuration to ActiveGate. Reason: INVALID_CONFIG_ERROR:Invalid configuration: Activation configuration contains too many SNMP devices:"

[Mike_L]

The monitoring configuration should automatically split up the endpoints into batches of 100 and spread them over the AG group. Please go with a support case if you see this again as it’s not working as designed.

[jegron]

Hi @AntonioSousa ,

I have the same issue : 

Failed to assign monitoring configuration to ActiveGate. Reason: INVALID_CONFIG_ERROR:Invalid configuration: Activation configuration contains too many SNMP devices: 336

Did you find a solution ?

[AntonioSousa]

@jegron,

At the moment, we separate monitoring configurations in blocks of one hundred. But as @Mike_L has said, it shouldn't occur. I'll have to test it again, last time I had more than 100, it failed.

[jegron]

Ok. I've just opened a case. It failed even though I put in a bucket of 500 devices.. I'll let you know if I get any news. Maybe a soft limit in our tenant.

[jegron]

Hi @AntonioSousa ,

For your information there is an issue with the bucket feature. It works if you set 100 in the bucket size. But if you let the field empty or set a value other than 100 it does not work.

Support told me that the patch would be available in ActiveGate version 1.283.