- Troubleshooting >
- Host Issues
Host Issues¶
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Logs Display java.lang.OutOfMemoryError
¶
If your logs display java.lang.OutOfMemoryError: Java heap space
,
you can adjust the Java Heap memory settings. Repeat the
following steps for every host running an Ops Manager instance except
dedicated Backup Daemon hosts.
- Linux Hosts
- Windows Hosts
Open
mms.conf
in your preferred text editor.Find this line:
The key values in this line are:
-Xmx
Java Heap Maximum Memory -Xms
Java Heap Starting Memory By default, these values are both set to 4,352 MB (
4352m
).Do not change other Java options
Changing any option values other than
-Xmx
and-Xms
could have an unexpected impact on the Ops Manager Application. Do not change other values without consulting MongoDB Support.Change the
-Xmx
and-Xms
values to a larger value. Both parameters should be set to the same value to remove any performance impact from the VM constantly reclaiming memory from the heap.The value is specified as
#k|m|g
: a number followed byk
(kilobytes),m
(megabytes), org
(gigabytes)
Example
To set the Java heap to 10 GB, set this value to:
-Xmx10g -Xms10g
Click Run from the Start menu.
Type
regedit
.Click OK.
If User Access Control asks Do you want to allow this app to make changes to your device?, click Yes.
Edit the following registry value:
Change the
-Xmx
and-Xms
values in the Options multi-line registry key to a larger value. Both parameters should be set to the same value to remove any performance impact from the VM constantly reclaiming memory from the heap. The value of the Options key should include the following:The key values in this block are:
-Xmx
Java Heap Maximum Memory -Xms
Java Heap Starting Memory By default, these values are both set to 4,352 MB (
4352m
).Do not change other Java options
Changing any option values other than
-Xmx
and-Xms
could have an unexpected impact on the Ops Manager Application. Do not change other values without consulting MongoDB Support.The value is specified as
#k|m|g
: a number followed byk
(kilobytes),m
(megabytes), org
(gigabytes)
Example
To set the Java heap to 10 GB, set this value to:
-Xmx10g -Xms10g
The optimal value for your Ops Manager installation depends upon your Ops Manager hosts’ architecture: platform, physical memory, etc. The goal of heap tuning is to balance the time the JVM spends reclaiming memory from objects that are no longer running, also known as garbage collection, and the frequency of garbage collection.
- Large heap sizes mean less frequent and slower garbage collection.
- Small heap sizes mean more frequent and faster garbage collection.
Important
Your Java heap size must not be set to a value greater than the
amount of physical memory in the Ops Manager host or less than the
default value of 4352m
(4,352 MB).
Increase User Limits¶
For the recommended User Limit (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. To learn more about ulimit
in MongoDB, see the
UNIX ulimit Settings
reference page in the MongoDB manual.
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 fails 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:
Warning
[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.