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- Frequently Asked Questions About On Prem MMS Monitoring
Frequently Asked Questions About On Prem MMS Monitoring¶
Host Configuration¶
How do I add a new host or server?¶
Click on the plus icon on the top of the hosts page.
Can I monitor Kerberos-enabled nodes?¶
Yes. On Prem MMS Monitoring does support monitoring for Kerberos-enabled MongoDB instances. See Connect to Hosts with Kerberos Authentication for more information.
How does MMS gather database statistics?¶
In most instances, On Prem MMS Monitoring will scale its request cycle to limit more expensive statistics gathering. The information on the DB Stats tab updates every 10 minutes, and the agent will throttle the frequency to reduce the impact on the database. [1] Even so, the “DB stats” operation impacts the performance of your database, as is possible when installations have a large number of databases and collections.
In these situations you must disable database stats collection. See the “DB Stats” section on the “Settings” page in the MMS Console before starting your agent.
| [1] | The DB Stats tab will not appear until 30 minutes after you add the host to On Prem MMS Monitoring |
On Prem MMS Monitoring Agent¶
Should I run more than one agent?¶
The Monitoring agent is fairly robust, and MMS automatically sends an Agent Down alert when a Monitoring agent becomes unavailable. For most applications, a single Monitoring agent is sufficient. However, you can choose to run a second agent to provide redundancy. Larger numbers of agents do not provide significant benefit. See: Monitoring Architecture for information.
Where should I run the Monitoring Agent?¶
The amount of resources the Monitoring Agent requires varies depending on infrastructure size, the number of nodes and the databases it’s monitoring. Run the agent on an existing machine with additional capacity that does not run a mongod instance or on a smaller dedicated instance.
Can I run the Monitoring agent on an AWS micro instances?¶
If you are monitoring five or fewer mongod instances, you can use
a AWS micro instance.
Why can’t the Monitoring agent connect to my host?¶
The most common problem is that the agent is unable to resolve the
hostname of the server. Check DNS and the /etc/hosts file.
The second most common problem is that there are firewall rules in place that prohibit access to the server from the agent.
To test the connection, login to the server running the agent and run:
mongo hostname:port/test If you are unable to connect, the agent
will not be able to connect.
In addition, On Prem MMS Monitoring does currently support monitoring for Kerberos-enabled nodes: if your host is using Kerberos for authentication, the On Prem MMS Monitoring Agent will not be able to connect to it.
How do I download the preconfigured agent?¶
You can download a preconfigured agent from the “Agent” section on the settings page.
How do I setup and configure the agent?¶
See the README file included in the agent download.
Data Presentation¶
What are all those vertical bars in my charts?¶
A red bar indicates a server restart.
A purple bar indicates the server is now a primary.
A yellow bar indicates the server is now a secondary.
Why is my hostname displayed in orange?¶
Your server either has startup warnings or a very low ulimit set. This can introduce problems. If your startup warning is about NUMA, see the MongoDB documentation. If you have a ulimit of 1024 or less, see the instructions for increasing your ulimit.
Why is my Monitoring agent highlighted in red on the Agents tab?¶
Your agent is out of date. For instructions on updating the agent, see: Update On-Prem MongoDB Management Service.