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This document provides advice for troubleshooting problems with Ops Manager.
For resolutions to alert conditions, see also Alert Resolutions.
Getting Started Checklist¶
To begin troubleshooting, complete these tasks to check for common, easily fixed problems:
- Authentication Errors
- Check Agent Output or Log
- Ensure Connectivity Between Agent and Monitored Hosts
- Ensure Connectivity Between Agent and Ops Manager Server
- Allow Agent to Discover Hosts and Collect Initial Data
If your MongoDB instances run with authentication enabled, ensure Ops Manager has the MongoDB credentials. See Configure MongoDB Authentication and Authorization.
Check Agent Output or Log¶
If you continue to encounter problems, check the agent’s output for errors. See Agent Logs for more information.
Ensure Connectivity Between Agent and Monitored Hosts¶
Ensure the system running the agent can resolve and connect to the
mongod processes. If you install multiple Monitoring Agents,
ensure that each Monitoring Agent can reach every
process in the deployment.
To confirm, log into the system where the agent is running and issue a command in the following form:
[hostname] with the hostname and
[port] with the
port that the database is listening on.
Ops Manager does not support port forwarding.
Ensure Connectivity Between Agent and Ops Manager Server¶
Verify that the Monitoring Agent can connect on TCP port 8443
(outbound) to the Ops Manager server (i.e.
Allow Agent to Discover Hosts and Collect Initial Data¶
Allow the agent to run for 5-10 minutes to allow host discovery and initial data collection.
The monitoring server does not start up successfully¶
Confirm the URI or IP address for the Ops Manager service is stored correctly
mongo.mongoUri property in the
If you don’t set this property, Ops Manager will fail while trying to connect to the default 127.0.0.1:27017 URL.
If the URI or IP address of your service changes, you must update the property with the new address. For example, update the address if you deploy on a system without a static IP address, or if you deploy on EC2 without a fixed IP and then restart the EC2 instance.
If the URI or IP address changes, then each user who access the service
must also update the address in the URL used to connect and in the
If you use the Ops Manager
encrypt the password used in the
mongo.mongoUri value, also add the
mongo.encryptedCredentials key to the
<install_dir>/conf/conf-mms.properties file and set the value for
this property to true:
For resolutions to alert conditions, see also Alert Resolutions.
Cannot Turn Off Email Notifications¶
There are at least two ways to turn off alert notifications:
Receive Duplicate Alerts¶
If the notification email list contains multiple email-groups, one or more people may receive multiple notifications of the same alert.
Receive “Host has low open file limits” or “Too many open files” error messages¶
These error messages appear on the Deployment page,
under a host’s name. They appear if the number of
available connections does not meet the Ops Manager-defined minimum value. These errors
are not generated by the
mongos instance and, therefore, will not
mongos log files.
On a host by host basis, the Monitoring Agent compares the number of open file descriptors and connections to the maximum connections limit. The max open file descriptors ulimit parameter directly affects the number of available server connections. The agent calculates whether or not enough connections exist to meet the Ops Manager-defined minimum value.
In ping documents, for each node and its
if the sum of the
current value plus the
available value is less than
maxConns configuration value set for a monitored host, the Monitoring
Agent will send a Host has low open file limits or Too
many open files message to Ops Manager.
Ping documents are data sent by Monitoring Agents to Ops Manager. To view ping documents, click the Deployment page, then click the host’s name, and then click Last Ping.
To prevent this error, we recommend you set
ulimit open files to 64000. We
also recommend setting the
maxConns command in the mongo shell to at least
the recommended settings.
Deployment Hangs in
If you have added or restarted a deployment and the deployment remains
In Progress state for several minutes, click View
Agent Logs and look for any errors.
If you diagnose an error and need to correct the deployment configuration:
- Click Edit Configuration and then click Edit Configuration again.
- Reconfigure the deployment.
- When you complete your changes, click Review Changes and then Confirm & Deploy.
If you shut down the deployment and still cannot find a solution, remove the deployment from Ops Manager.
Monitoring Agent Fails to Collect Data¶
Possible causes for this state:
- If the Monitoring Agent can’t connect to the server because of networking restrictions or issues (i.e. firewalls, proxies, routing.)
- If your database is running with SSL. You must enable SSL either globally or on a per-host basis. See Configure Monitoring Agent for SSL and Enable SSL for a Deployment for more information.
- If your database is running with authentication. You must supply Ops Manager with the authentication credentials for the host. See Configure MongoDB Authentication and Authorization.
Hosts are not Visible¶
Problems with the Monitoring Agent detecting hosts can be caused by a few factors.
Host not added: In Ops Manager, click Deployment, then click the Processes tab, then click the Add Host button. In the New Host window, specify the host type, internal hostname, and port. If appropriate, add the database username and password and whether or not Ops Manager should use SSL to connect with your Monitoring Agent. Note it is not necessary to restart your Monitoring Agent when adding (or removing) a host.
Accidental duplicate mongods If you add the host after a crash and restart the Monitoring Agent, you might not see the hostname on the Ops Manager Deployment page. Ops Manager detects the host as a duplicate and suppresses its data. To reset, click Settings, then Group Settings, then the Reset Duplicates button.
Monitoring Agents cannot detect hosts: If your hosts exist across multiple data centers, make sure that all of your hosts can be discovered by all of your Monitoring Agents.
Cannot Delete a Host¶
In rare cases, the
mongod is brought down and the replica set
is reconfigured. The down host cannot be deleted and returns an error
message, “This host cannot be deleted because it is enabled for backup.”
Contact MongoDB Support for help in
deleting these hosts.
Additional Information on Groups¶
Create a group to monitor additional segregated systems or environments for servers, agents, users, and other resources. For example, your deployment might have two or more environments separated by firewalls. In this case, you would need two or more separate Ops Manager groups.
API and shared secret keys are unique to each group. Each group requires its own agent with the appropriate API and shared secret keys. Within each group, the agent needs to be able to connect to all hosts it monitors in the group.
For information on creating and managing groups, see Create a Group.
munin-node is a third-party package. For problems related to
munin-node, refer to the
Install and configure the
munin-node service on the MongoDB server(s) to
be monitored before starting Ops Manager monitoring. The Ops Manager agent README file
provides guidelines to install
See Configure Hardware Monitoring with munin-node for details
about monitoring hardware with
Red Hat Enterprise Linux (RHEL 6, 7) can generate the following error messages.
No package munin-node is available Error¶
To correct this error:
Follow the instructions on the Extra Packages for Enterprise Linux repository wiki page to install the
epel-release rpmfor your version of your enterprise Linux.
After the package is installed, type this command to install
munin-nodeand all of its dependencies:
sudo yum install munin-node
munin-nodeis installed, check to see if the
munin-nodeservice is running. If it is not, type these commands to start the
service munin-node status service munin-node start
Non-localhost IP Addresses are Blocked¶
By default, munin blocks incoming connections from non-localhost IP addresses.
/var/log/munin/munin-node.log file will display a
“Denying connection” error for your non-localhost IP address.
To fix this error, open the
munin-node.conf configuration file and comment
out these two lines:
allow ^127\.0\.0\.1$ allow ^::1$
Then add this line to the
munin-node.conf configuration file with a pattern
that matches your subnet:
munin-node after editing the configuration file for changes to take effect.
Verifying iostat and Other Plugins/Services Returns “# Unknown service” Error¶
The first step is to confirm there is a problem. Open a telnet session and
telnet HOSTNAME 4949 <default/required munin port> fetch iostat fetch iostat_ios fetch cpu
iostat_ios plugin creates the
iotime chart, and the
plugin creates the
If any of these telnet
fetch commands returns an “# Unknown Service” error,
create a link to the plugin or service in /etc/munin/plugins/ by typing these
cd /etc/munin/plugins/ sudo ln -s /usr/share/munin/plugins/<service> <service>
<service> with the name of the service that generates the error.
Missed SMS Authentication Tokens¶
Unfortunately SMS is not a 100% reliable delivery mechanism for messages, especially across international borders. The Google authentication option is 100% reliable. Unless you must use SMS for authentication, use the Google Authenticator application for two-factor authentication.
If you do not receive the SMS authentication tokens:
- Refer to the Settings page for more details about using two-factor authentication. This page includes any limitations which may affect SMS delivery times.
- Enter the SMS phone number with country code first followed by the area code and the phone number. Also try 011 first followed by the country code, then area code, and then the phone number.
If you do not receive the authentication token in a reasonable amount of time, contact your Ops Manager system administrator.
Forgot to Change MONGODB-CR Error¶
If your MongoDB deployment uses LDAP for authentication, and you find the following error message:
You forget to change "MONGODB-CR" to "LDAP (PLAIN)" since they both take username/password.
Then make sure that you specified the
LDAP (PLAIN) as is the
authentication mechanism for both the Monitoring Agent and the Backup
Agent. See Configure Backup Agent for LDAP Authentication and
Configure Monitoring Agent for LDAP.
Logs Display MongodVersionException¶
MongodVersionException can occur if the Backup Daemon’s host cannot access the internet to download the version
or versions of MongoDB required for the backed-up databases. Each
database requires a version of MongoDB that matches the database’s
version. Specifically, for each instance you must run the latest stable
release of that release series. For versions earlier than 2.4, the
database requires the latest stable release of 2.4.
If the Daemon runs without access to the internet, you must manually download the required MongoDB versions, as described here:
Go to the MongoDB downloads page and download the appropriate versions for your environment.
Copy the download to the Daemon’s host.
Decompress the download into the directory specified in the
mongodb.release.directorysetting in the Daemon’s
conf-daemon.propertiesfile. For the file’s location, see Ops Manager Configuration.
Within the directory specified in the
mongodb.release.directorysetting, the folder structure for MongoDB should look like the following:
<path-to-mongodb-release-directory>/ |-- mongodb-<platform> | |-- THIRD-PARTY-NOTICES | |-- README | |-- GNU-AGPL-3.0 | |-- bin | | |-- bsondump | | |-- mongo | | |-- mongod | | |-- mongodump | | |-- mongoexport | | |-- mongofiles | | |-- mongoimport | | |-- mongooplog | | |-- mongoperf | | |-- mongorestore | | |-- mongos | | |-- mongostat | | |-- mongotop
Insufficient Oplog Size Error¶
When using the Ops Manager interface to back up a MongoDB cluster, Ops Manager checks to see if the cluster’s oplogs are, based on their recent usage, large enough to hold a minimum of 3 hours worth of data based on the last 24 hours of usage patterns. If the oplogs are not large enough, it may be possible that the oplogs may have turned over multiple times, creating a gap between where a backup ends and an oplog starts.
If the oplog size check fails, the user cannot enable backups and is shown the warning:
Insufficient oplog size: The oplog window must be at least 3 hours over the last 24 hours for all members of replica set <name>. Please increase the oplog.
If possible, wait to start a backup until the oplog has had sufficient time to meet the size requirement.
If this is not possible, the minimum oplog size value can be changed.
mms.backup.minimumOplogWindowHours for how to set this
Do not change the minimum oplog size unless you are certain smaller backups still provide useful backups.
MongoDB recommends only changing this value temporarily to permit a test backup job to execute. The minimum oplog size value should be reset to the default as soon as possible. If an oplog is set to too small of a value, it can result in a gap between a backup job and an oplog which makes the backup unusuable for restores. Stale backup jobs must be resynchronized before it can be used for restores.
Understanding the risks given, you can start backups using this changed minimum value. Once you pass the 24 hour mark, you should reset this minimum value to preserve the sanity check for the global Ops Manager installation going forward.
Logs Display OutOfMemoryError¶
If your logs display
OutOfMemoryError, ensure you are running with
sufficient ulimits and RAM.
For the recommended ulimit setting, see the FAQ on Receive “Host has low open file limits” or “Too many open files” error messages.
Ops Manager infers the host’s
ulimit setting using the total number of
available and current connections. For more information about ulimits
in MongoDB, see the UNIX ulimit Settings
Ensure Sufficient RAM for All Components¶
Ensure that each server has enough RAM for the components it runs. If a server runs multiple components, its RAM must be at least the sum of the required amount of RAM for each component.
For the individual RAM requirements for the Ops Manager Application server, Ops Manager Application Database, Backup Daemon server, and Backup Database, see Ops Manager System Requirements.
Obsolete Config Settings¶
Ops Manager will fail to start if there are obsolete configuration settings set in the conf-mms.properties file. If there is an obsolete setting, the log lists an “Obsolete Setting” error as in the following:
[OBSOLETE SETTING] Remove "mms.multiFactorAuth.require" or replace "mms.multiFactorAuth.require" with "mms.multiFactorAuth.level".
You will need to remove or replace the obsolete property in the
conf-mms.properties file before you can start Ops Manager.
Ops Manager Automation allows you to deploy, configure, and manage MongoDB deployments with the Ops Manager UI. Ops Manager Automation relies on an Automation Agent, which must be installed on every server in the deployment. The Automation Agents periodically poll the Ops Manager service to determine the current goal, and continually report their status to Ops Manager.
To use Automation, you must install the Automation Agent on each server that you want Ops Manager to manage.
Automation Runs Only on 64-bit Architectures¶
Ops Manager provides only 64-bit downloads of the Automation Agent.
Using Own Hardware¶
If you deploy Automation manually, ensure that you have one Automation Agent on every server.
If you deploy the agent manually, you must create MongoDB’s
dbpathand the directory for the MongoDB binaries and ensure that the user running the agent owns these directories.
If you install using the
rpmpackage, the agent runs as the
mongoduser; if using the
debpackage, the agent runs as the
mongodbuser. If you install using the
tar.gzarchive file, you can run the agent as any user.
All hosts must be able to allow communication between MongoDB
ports. The default is
27017, but you can configure alternate port
ranges in the Ops Manager interface.
The Automation Agent must be able to connect to
Ops Manager on port
For more information on access to ports and IP addresses, see
After completing the automation configuration, always ensure that the deployment plan satisfies the needs of your deployment. Always double check hostnames and ports before confirming the deployment.
- Ensure that you provision machines with enough space to run MongoDB and support the requirements of your data set.
- Ensure that you provision sufficient machines to run your
mongodshould run on its own host.
Frequent Connection Timeouts¶
The Automation Agent may frequently time out of connections for one or more of the following reasons:
- High network latency
- High server load
- Large SSL keys
- Lack of SSL accelerator
- Insufficient CPU speed
By default, connections time out after 40 seconds. MongoDB recommends
gradually increasing the value of the
Automation Agent configuration setting to prevent frequent premature
connection timeouts. However, increasing this value also increases the
time required to deploy future configuration changes. Experiment with
small, incremental increases until you determine the optimum value for
your deployment. See
Connection Settings at Automation Agent Configuration
for more information.