Symptoms

• Bamboo Server is installed on a Linux host.
• The entire Bamboo Server process suddenly terminates without warning. That is to say, the Process ID (PID) is gone.
• The browser shows a generic "cannot connect" or similar error, indicating that it is not able to reach the webpage
• Nothing out of the ordinary appears in the Bamboo Server application logs (<bamboo-home>/logs/atlassian-bamboo.log), since the application was terminated without properly shutting down
• Similarly, Tomcat logs (<bamboo-install>/logs/catalina.out) also do not show errors

Causes and Diagnosis

Bamboo Server does not terminate its own PID unless a stop-bamboo.sh is executed (which writes shutdown messages to the log). An unexpected PID termination clearly indicates the work of an external entity. Some examples include:

• kill -9 (user-triggered or via script) 
• Linux OOM-Killer

On the host machine, look in the /var/log/ directory for the syslog or messages, and locate the timestamps spanning the approximate time when the PID was terminated. If you see entries similar to the following, then you know the process was a victim of the OOM-Killer:

Apr  8 11:29:48 Bamboo01 kernel: Out of memory: Kill process 1386 (java) score 358 or sacrifice
Apr  8 11:29:48 Bamboo01 kernel: Killed process 5388, UID 4048, (java) total-vm:1331564kB, anon
Apr  8 11:29:51 Bamboo01 kernel: java invoked oom-killer: gfp_mask=0x200da, order=0, oom_adj=0,

Use can use dmesg and search for lines around the killed process.

dmesg -T | grep -C 5 -i “killed process”

Workaround

The way to mitigate this type of issue is to Add Swap Space to the system. Having a Swap location will keep Bamboo from crashing while working on a permanent resolution (Adding RAM). This can be done live without having to stop Linux or Bamboo. This will have performance impacts on Bamboo so this should only be used to prevent a full outage. 

• Decide where on the disk there is available space.  This example will put the swap space in the root user's home directory

• Create a file on the local disk.  This is an example of a 2G swap file:

  # dd if=/dev/zero of=/root/myswapfile bs=1M count=2048

• Change the permission of the swap file so that only the root user can access it

  # chmod 600 /root/myswapfile

• Make and enable this file as a swap file using the mkswap command

  # mkswap /root/myswapfile
  # swapon /root/myswapfile

• Verify whether the newly created swap area is available for your use

  # swapon -s

Resolution

In the case of the OOM-Killer, the possible resolutions would be to:

• Increase the amount of memory available on the host machine itself.

• Decrease the amount of memory allocated to Bamboo Server or competing processes on the machine: Configuring your System Properties

• Profile the memory usage during periods of high usage and understand if there are other processes increasing the footprint. For example, running the below ps command will help identify the top 10 memory consumers at the time it is run:

  $ ps -eo pmem,pcpu,vsize,pid,cmd | sort -k 1 -nr | head -10

• Disable the OOM-Killer (not recommended).

If you wish to exclude the bamboo service from OOM-Killer, you can follow the below steps, the below example was tested on RHEL machine.

• Run the below command   

  systemctl edit bamboo.service

• Add the below 2 lines

  [Service]
  OOMScoreAdjust=-1000

• Save & exit and the Bamboo process will be excluded permanently.