OOM Killer Resolutions: Processes with High Risk of Memory Leak

Pay special attention to the processes in this group as to the most probable cause of your out-of-memory issues (sorted based on server role):

• Load Balancers
• Application Servers
• Database Servers
• Common Processes for Different-Type Stacks

• Load Balancers

Common recommendations

Allocate more RAM to corresponding node-handled services could just require more memory for normal operability.

Related processes

Process	Resolution
varnishd	Allocate more RAM to node – handled services could just require more memory for normal operability

• Application Servers

Click on points within the list below to view some common recommendations on dealing with memory shortage issues considering used programming language, as well as appropriate resolutions for the most demanding related processes:

• JavaCommon recommendations review the main memory management configurations for your Java machine and, if required, adjust them according to your application needs, e.g.:java -Xmx2048m -Xms256mwhere
• Xmx flag specifies the maximum heap memory that could be allocated for a Java Virtual Machine (JVM)
• Xms flag defines the initial memory allocation pool

Refer to the official documentation for more info on Java memory management system.

• PHP
• Database Servers

Click on the required DB stack within the list below to reveal appropriate common recommendations on coping with OOM issues, as well as resolutions for particular killed processes:

Common Processes for Different-Type Stacks

Common recommendations

Processes in this section can be run and, subsequently, killed within different node types. Thus, OOM resolutions for them vary and depend on a process itself – see the table below to find the appropriate recommendations.

• Related processes

Process	Stack	Resolution
httpd	PHP Ruby Python MySQL MongoDB PostgreSQL	1. Check the average amount of RAM, used by each httpd instance 2. Remove the Jelastic autoconfiguration mark within the /etc/httpd/httpd.conf  file 3. Decrease ServerLimit and MaxClients values according to the formula: (Total_RAM – 5%) / Average_RAM
lsyncd	PHP NodeJS Python	Allocate more RAM to a node – handled services could just require more memory for normal operability
httpd.itk	PHP Ruby Python	1. Check the average amount of RAM, used by each httpd instance 2. Remove the Jelastic autoconfiguration mark within the /etc/httpd/httpd.conf  file 3. Decrease ServerLimit and MaxClients values according to the formula: (Total_RAM – 5%) / Average_RAM
procmail	Any	Restart container in order to restore the process
vsftpd	Any
yum	Any
cc1	3rd party	Allocate more RAM to a node – handled services could just require more memory for normal operability
clamd	3rd party
ffmpeg	3rd party
firefox	3rd party
newrelic-daemon	3rd party	Restart the main stack service (nginx, tomcat, nodejs, etc)