Since it has begun to be utilized by a new webapp server, storage0 is experiencing out of memory events.
Memory usage was relatively low until 2018-06-15:
http://munin.internal.softwareheritage.org/euwest.azure.internal.softwareheritage.org/storage0.euwest.azure.internal.softwareheritage.org/memory.html
Since then, various processes have reported being unable to allocate memory:
03:58 < swhbot> icinga PROBLEM: service journalbeat on storage0.euwest.azure.internal.softwareheritage.org is UNKNOWN: Fork failed with error code 12 (Cannot allocate memory)
and the kernel had to kill gunicorn processes:
[Mon Jun 18 11:16:29 2018] Out of memory: Kill process 55922 (gunicorn3) score 14 or sacrifice child [Mon Jun 18 11:16:29 2018] Killed process 55922 (gunicorn3) total-vm:798648kB, anon-rss:468264kB, file-rss:0kB, shmem-rss:0kB [Mon Jun 18 11:16:29 2018] oom_reaper: reaped process 55922 (gunicorn3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB