SAM Scalability Engine Guidelines
Stackable Polling Engines
SAM 6.2 and later
2 polling engines can be installed on a single server.
SAM 5.5 and later
Main Polling Engine Limits
~8 - 10k component monitors per polling engine
25 - 50 concurrent Orion Web Console users
1 Additional Polling Engine for every 8 - 10k component monitors.
Maximum of 150k component monitors per primary SolarWinds SAM installation (1 SAM server + 14 Additional Polling Engines).
For more information about licensing, see the SAM Licensing Guide.
WAN and/or Bandwidth Considerations
Minimal monitoring traffic is sent between the primary SAM server and any Additional Polling Engines that are connected over a WAN. Most traffic related to monitoring is between an Additional Polling Engine and the SolarWinds database. Bandwidth requirements depend on the size of the relevant component monitor. Based on 67.5 kB / WMI poll and a 5 minute polling frequency, the estimate is 1.2 Mbps for 700 component monitors. For more information, see
WMI is best suited for environments where latency is < 100ms.
Scalability Engine Deployment Options
Installing Additional Polling Engines
Activating Stackable Poller Licenses
Frequently Asked Questions
Does each module have its own polling engine?
No, an Additional Polling Engine may have all relevant modules installed on it, and it performs polling for all installed modules. An Additional Polling Engine works the same way as your Main Polling Engine on your main server.
For example, if you have NPM and SAM installed, install one Additional Polling Engine and it performs polling for both NPM and SAM.
Are polling limits cumulative or independent? For example, can a single polling engine poll 12k NPM elements AND 10k SAM monitors together?
Yes, a single polling engine can poll up to the limits of each module installed, if sufficient hardware resources are available.
Are there different size license available for the Additional Polling Engine?
No, the Additional Polling Engine is available with an unlimited license.
Can you add an Additional Polling Engine to any size module license?
Yes, you can add an Additional Polling Engine to any size license.
Adding an Additional Polling Engine does not increase your license size. For example, if you are licensed for an NPM SL100, adding an Additional Polling Engine does not increase the licensed limit of 100 nodes/interfaces/volumes, but the polling load is spread across two polling engines.
Will an Additional Polling Engine allow me to monitor overlapping IPs?
Yes, you can add nodes with the same IP Address to separate polling engines to monitor overlapping IP Addresses.
What happens if the connection from a polling engine to the Orion Database Server is lost?
If there is a connection outage to the Orion Database Server, polling engines use Microsoft Message Queuing (MSMQ) to cache the polled data on the Additional Polling Engine servers.
The amount of data that can be cached depends on the disk space available on the polling engine server. The default storage space is 1 GB. Up to one hour of data can be cached.
When the connection to the database is restored, the Orion Database Server is updated with the locally cached data, the oldest data is processed first.
If the database connection is broken for a longer than an hour, the collector queue becomes full, the newest data is discarded until a connection to the database is re-established.