My company is considering a self-hosted option for a combination of JIRA, Confluence and MySQL running behind an nginx proxy. We are a very small team of 5, and expect extremely mild usage for now. I hardly even expect any concurrent usage at this point.
I am a bit puzzled by the various guidelines posted by Atlassian: https://confluence.atlassian.com/enterprise/jira-sizing-guide-461504623.html https://confluence.atlassian.com/adminjiraserver075/jira-applications-installation-requirements-935390824.html https://confluence.atlassian.com/doc/example-size-and-hardware-specifications-from-customer-survey-76840961.html https://confluence.atlassian.com/doc/server-hardware-requirements-guide-30736403.html
It seems they don't want to bother providing actual minimum hardware requirements. For example, on the same page they could say "minimum heap size to allocate to Confluence is 1 GB and 1 GB for Synchrony (which is required for collaborative editing)" and also that " minimum hardware recommendation" is 6GB. The leap from 1 required plus 1 optional to 6 recommended minimum is bizarre, to say the least.
I think what I want to know is whether I will be able to fit this setup into a 2GB RAM machine or a 4GB RAM machine (both dual CPU).
OK, I have done a test with following configuration:
This 4GB RAM machine is barely capable of running this setup:
$ free -m
total used free shared buff/cache available
Mem: 3951 3553 107 0 291 157
Swap: 974 725 249
CPU usage was going up to 200% only during initialisation when JIRA and Confluence started with empty home dirs. The following top output is after:
$ top -o %MEM | head -15
top - 16:14:33 up 6:12, 2 users, load average: 0.15, 0.04, 0.01
Tasks: 132 total, 1 running, 131 sleeping, 0 stopped, 0 zombie
%Cpu(s): 2.6 us, 0.5 sy, 0.0 ni, 95.8 id, 1.0 wa, 0.0 hi, 0.1 si, 0.0 st
KiB Mem : 4046364 total, 128808 free, 3638444 used, 279112 buff/cache
KiB Swap: 998396 total, 252956 free, 745440 used. 161144 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
6328 bin 20 0 3306232 1.468g 0 S 0.0 38.1 12:03.27 java
6418 bin 20 0 2860000 1.320g 0 S 0.0 34.2 10:56.24 java
7205 bin 20 0 2807088 476592 1724 S 0.0 11.8 1:58.37 java
5752 999 20 0 1815480 99804 4728 S 0.0 2.5 1:11.29 mysqld
1070 root 20 0 621908 28672 8904 S 0.0 0.7 0:30.74 dockerd
1179 root 20 0 623004 7536 2520 S 0.0 0.2 0:16.66 docker-containe
968 root 20 0 291352 6536 1912 S 0.0 0.2 0:00.77 snapd
8310 root 20 0 15388 5064 3056 S 0.0 0.1 0:21.39 docker-gen
Confluence also allocated ~500MB RAM to Synchrony:
$ ps aux --sort -rss | head -4
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
bin 6328 3.3 38.3 3306232 1551120 ? Ssl 10:14 12:12 /usr/lib/jvm/java-1.8-openjdk/bin/java -Djava.util.logging.config.file=/opt/atlassian/confluence...
bin 6418 2.9 34.1 2860000 1382868 ? Ssl 10:14 10:57 /usr/lib/jvm/java-1.8-openjdk/bin/java -Djava.util.logging.config.file=/opt/atlassian/jira/...
bin 7205 0.5 11.7 2807088 476588 ? Sl 10:44 1:59 /usr/lib/jvm/java-1.8-openjdk/jre/bin/java -classpath /opt/atlassian/confluence/temp/... synchrony.core sql
During JIRA and Confluence install stage, MySQL peaked at around 500MB RAM usage, and during normal operation it sits around 100MB.
In my attempts, a 2GB machine was only enough to run either JIRA or Confluence without MySQL.
Conclusion: It looks like 4GB RAM Dual core machine is the absolute minimum required for JIRA+Confluence+MySQL. But keep in mind that such a machine is barely enough for a practically empty project.
I personally was not expecting these applications to be that RAM hungry being empty.