Here the system log from the time Elasticsearch stopped.
journalctl --since "2022-01-15 01:30" --until "2022-01-15 02:00"
Jan 15 01:52:27 Server kernel: rpimonitord invoked oom-killer: gfp_mask=0x100cca(GFP_HIGHUSER_MOVABLE), order=0, oom_score_adj=0
Jan 15 01:52:27 Server kernel: CPU: 2 PID: 904 Comm: rpimonitord Not tainted 5.10.63-v8+ #1488
Jan 15 01:52:27 Server kernel: Hardware name: Raspberry Pi 4 Model B Rev 1.4 (DT)
Jan 15 01:52:27 Server kernel: Call trace:
Jan 15 01:52:27 Server kernel: dump_backtrace+0x0/0x1b8
Jan 15 01:52:27 Server kernel: show_stack+0x20/0x30
Jan 15 01:52:27 Server kernel: dump_stack+0xf0/0x158
Jan 15 01:52:27 Server kernel: dump_header+0x4c/0x204
Jan 15 01:52:27 Server kernel: oom_kill_process+0x1f8/0x200
Jan 15 01:52:27 Server kernel: out_of_memory+0xf0/0x330
Jan 15 01:52:27 Server kernel: __alloc_pages_slowpath.constprop.133+0x820/0xb80
Jan 15 01:52:27 Server kernel: __alloc_pages_nodemask+0x2bc/0x330
Jan 15 01:52:27 Server kernel: pagecache_get_page+0x144/0x2e0
Jan 15 01:52:27 Server kernel: filemap_fault+0x520/0x9e0
Jan 15 01:52:27 Server kernel: ext4_filemap_fault+0x3c/0x818
Jan 15 01:52:27 Server kernel: __do_fault+0x44/0x110
Jan 15 01:52:27 Server kernel: handle_mm_fault+0x6a8/0xcb8
Jan 15 01:52:27 Server kernel: do_page_fault+0x148/0x3e8
Jan 15 01:52:27 Server kernel: do_translation_fault+0x58/0x70
Jan 15 01:52:27 Server kernel: do_mem_abort+0x48/0xa8
Jan 15 01:52:27 Server kernel: el0_ia+0x68/0xc8
Jan 15 01:52:27 Server kernel: el0_sync_handler+0x78/0xb8
Jan 15 01:52:27 Server kernel: el0_sync+0x180/0x1c0
Jan 15 01:52:27 Server kernel: Mem-Info:
Jan 15 01:52:27 Server kernel: active_anon:263544 inactive_anon:694226 isolated_anon:0
active_file:231 inactive_file:0 isolated_file:0
unevictable:387 dirty:0 writeback:0
slab_reclaimable:5894 slab_unreclaimable:5440
mapped:7320 shmem:275152 pagetables:2615 bounce:0
free:6987 free_pcp:245 free_cma:468
Jan 15 01:52:27 Server kernel: Node 0 active_anon:1054176kB inactive_anon:2776904kB active_file:924kB inactive_file:0kB unevictable:1548kB isolated(anon):0kB isolated(file):0kB mapped:29280kB dirty:0kB writeback:0kB shmem:1100608kB writeback_tmp:0kB kernel_stack:3664kB all_unreclaimable? no
Jan 15 01:52:27 Server kernel: DMA free:15576kB min:3900kB low:4872kB high:5844kB reserved_highatomic:0KB active_anon:600340kB inactive_anon:306160kB active_file:0kB inactive_file:220kB unevictable:0kB writepending:0kB present:1021952kB managed:937872kB mlocked:0kB pagetables:1768kB bounce:0kB free_pcp:960kB local_pcp:280kB free_cma:1872kB
Jan 15 01:52:27 Server kernel: lowmem_reserve[]: 0 2929 2929 2929
Jan 15 01:52:27 Server kernel: DMA32 free:12372kB min:12480kB low:15600kB high:18720kB reserved_highatomic:0KB active_anon:453836kB inactive_anon:2470744kB active_file:0kB inactive_file:284kB unevictable:1548kB writepending:0kB present:3080192kB managed:2999332kB mlocked:1548kB pagetables:8692kB bounce:0kB free_pcp:20kB local_pcp:0kB free_cma:0kB
Jan 15 01:52:27 Server kernel: lowmem_reserve[]: 0 0 0 0
Jan 15 01:52:27 Server kernel: DMA: 592*4kB (UMEC) 327*8kB (UMEC) 129*16kB (UEC) 102*32kB (UEC) 44*64kB (UEC) 10*128kB (UEC) 0*256kB 3*512kB (C) 0*1024kB 0*2048kB 0*4096kB = 15944kB
Jan 15 01:52:27 Server kernel: DMA32: 409*4kB (UME) 548*8kB (UME) 208*16kB (UME) 43*32kB (UM) 30*64kB (UME) 2*128kB (M) 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 12900kB
Jan 15 01:52:27 Server kernel: 275866 total pagecache pages
Jan 15 01:52:27 Server kernel: 0 pages in swap cache
Jan 15 01:52:27 Server kernel: Swap cache stats: add 0, delete 0, find 0/0
Jan 15 01:52:27 Server kernel: Free swap = 0kB
Jan 15 01:52:27 Server kernel: Total swap = 0kB
Jan 15 01:52:27 Server kernel: 1025536 pages RAM
Jan 15 01:52:27 Server kernel: 0 pages HighMem/MovableOnly
Jan 15 01:52:27 Server kernel: 41235 pages reserved
Jan 15 01:52:27 Server kernel: 16384 pages cma reserved
Jan 15 01:52:27 Server kernel: Tasks state (memory values in pages):
Jan 15 01:52:27 Server kernel: [ pid ] uid tgid total_vm rss pgtables_bytes swapents oom_score_adj name
Jan 15 01:52:27 Server kernel: [ 137] 0 137 6115 597 73728 0 -250 systemd-journal
Jan 15 01:52:27 Server kernel: [ 185] 0 185 5016 282 49152 0 -1000 systemd-udevd
Jan 15 01:52:27 Server kernel: [ 306] 0 306 884 358 32768 0 0 vmtouch
Jan 15 01:52:27 Server kernel: [ 313] 0 313 749 26 36864 0 0 rngd
Jan 15 01:52:27 Server kernel: [ 334] 0 334 1074 48 36864 0 0 dropbear
Jan 15 01:52:27 Server kernel: [ 405] 0 405 24837 325 61440 0 0 dhclient
Jan 15 01:52:27 Server kernel: [ 471] 101 471 22661 850 73728 0 0 systemd-timesyn
Jan 15 01:52:27 Server kernel: [ 492] 0 492 3107 966 45056 0 0 dietpi-dashboar
Jan 15 01:52:27 Server kernel: [ 502] 0 502 1017 26 36864 0 0 agetty
Jan 15 01:52:27 Server kernel: [ 503] 0 503 1017 28 40960 0 0 agetty
Jan 15 01:52:27 Server kernel: [ 673] 0 673 18129 596 118784 0 0 nmbd
Jan 15 01:52:27 Server kernel: [ 717] 0 717 22096 1168 155648 0 0 smbd
Jan 15 01:52:27 Server kernel: [ 719] 0 719 21615 735 147456 0 0 smbd-notifyd
Jan 15 01:52:27 Server kernel: [ 720] 0 720 21617 737 143360 0 0 cleanupd
Jan 15 01:52:27 Server kernel: [ 723] 105 723 15628 592 102400 0 0 redis-server
Jan 15 01:52:27 Server kernel: [ 781] 104 781 454773 49713 626688 0 0 mariadbd
Jan 15 01:52:27 Server kernel: [ 823] 0 823 88563 2119 176128 0 0 php-fpm7.4
Jan 15 01:52:27 Server kernel: [ 880] 33 880 2480 659 49152 0 0 lighttpd
Jan 15 01:52:27 Server kernel: [ 902] 0 902 18217 4060 126976 0 0 rpimonitord
Jan 15 01:52:27 Server kernel: [ 903] 1000 903 18349 4198 126976 0 0 rpimonitord
Jan 15 01:52:27 Server kernel: [ 904] 0 904 18264 4069 126976 0 0 rpimonitord
Jan 15 01:52:27 Server kernel: [ 914] 0 914 1413 64 40960 0 0 cron
Jan 15 01:52:27 Server kernel: [ 2020] 106 2020 1471905 600355 5423104 0 0 java
Jan 15 01:52:27 Server kernel: [ 2221] 106 2221 25951 142 77824 0 0 controller
Jan 15 01:52:27 Server kernel: [ 5386] 0 5386 1140 96 36864 0 0 dropbear
Jan 15 01:52:27 Server kernel: [ 21156] 0 21156 1949 625 49152 0 0 bash
Jan 15 01:52:27 Server kernel: [ 21187] 0 21187 3552 422 61440 0 0 mc
Jan 15 01:52:27 Server kernel: [ 21189] 0 21189 1948 625 40960 0 0 bash
Jan 15 01:52:27 Server kernel: [ 21501] 0 21501 2014 694 49152 0 0 bash
Jan 15 01:52:27 Server kernel: [ 24723] 33 24723 89797 8935 233472 0 0 php-fpm7.4
Jan 15 01:52:27 Server kernel: [ 24774] 33 24774 114377 8663 249856 0 0 php-fpm7.4
Jan 15 01:52:27 Server kernel: [ 24838] 33 24838 89776 8635 225280 0 0 php-fpm7.4
Jan 15 01:52:27 Server kernel: [ 24854] 33 24854 89285 8123 221184 0 0 php-fpm7.4
Jan 15 01:52:27 Server kernel: [ 57209] 0 57209 2228 116 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57210] 33 57210 517 17 36864 0 0 sh
Jan 15 01:52:27 Server kernel: [ 57211] 33 57211 63301 9284 225280 0 0 php
Jan 15 01:52:27 Server kernel: [ 57243] 0 57243 2136 105 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57251] 0 57251 2136 105 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57252] 0 57252 2136 103 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57256] 0 57256 2136 103 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57258] 0 57258 2136 103 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57264] 0 57264 2136 103 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57271] 0 57271 2136 103 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57275] 0 57275 2136 90 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57278] 0 57278 2136 90 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57280] 0 57280 2136 90 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57285] 0 57285 2136 90 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57288] 0 57288 2136 90 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57290] 0 57290 2136 90 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57295] 0 57295 2136 89 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57296] 0 57296 2136 89 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57301] 0 57301 2027 79 49152 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57304] 0 57304 22136 760 139264 0 0 smbd
Jan 15 01:52:27 Server kernel: [ 57305] 0 57305 1637 72 45056 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57309] 0 57309 1534 68 45056 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57310] 0 57310 1534 68 45056 0 0 cron
Jan 15 01:52:27 Server kernel: [ 57314] 0 57314 18129 596 114688 0 0 nmbd
Jan 15 01:52:27 Server kernel: [ 57315] 0 57315 1413 64 40960 0 0 cron
Jan 15 01:52:27 Server kernel: oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0,global_oom,task_memcg=/,task=java,pid=2020,uid=106
Jan 15 01:52:27 Server kernel: Out of memory: Killed process 2020 (java) total-vm:5887620kB, anon-rss:2401228kB, file-rss:0kB, shmem-rss:192kB, UID:106 pgtables:5296kB oom_score_adj:0
Jan 15 01:52:27 Server kernel: oom_reaper: reaped process 2020 (java), now anon-rss:0kB, file-rss:0kB, shmem-rss:32kB
Jan 15 01:52:23 Server systemd[1]: elasticsearch.service: Main process exited, code=killed, status=9/KILL
Jan 15 01:52:23 Server systemd[1]: elasticsearch.service: Failed with result 'signal'.
Jan 15 01:52:23 Server systemd[1]: elasticsearch.service: Unit process 2221 (controller) remains running after unit stopped.
Jan 15 01:52:23 Server systemd[1]: elasticsearch.service: Consumed 22min 47.135s CPU time.
Jan 15 01:52:23 Server systemd[1]: Starting Clean php session files...
Jan 15 01:52:23 Server CRON[57252]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:23 Server CRON[57295]: pam_unix(cron:session): session opened for user root(uid=0) by (uid=0)
Jan 15 01:52:23 Server CRON[57271]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:23 Server CRON[57310]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:23 Server CRON[57278]: pam_unix(cron:session): session opened for user root(uid=0) by (uid=0)
Jan 15 01:52:23 Server CRON[57305]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:23 Server CRON[57288]: pam_unix(cron:session): session opened for user root(uid=0) by (uid=0)
Jan 15 01:52:23 Server CRON[57315]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:23 Server CRON[57258]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:23 Server CRON[57296]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:23 Server CRON[57301]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:23 Server CRON[57264]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:23 Server CRON[57319]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:23 Server CRON[57309]: pam_unix(cron:session): session opened for user root(uid=0) by (uid=0)
Jan 15 01:52:23 Server CRON[57280]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:23 Server CRON[57275]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:23 Server CRON[57243]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:23 Server CRON[57256]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:23 Server CRON[57290]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:23 Server CRON[57285]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:23 Server CRON[57251]: pam_unix(cron:session): session opened for user root(uid=0) by (uid=0)
Jan 15 01:52:23 Server CRON[57325]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:52:23 Server CRON[57328]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:52:23 Server CRON[57327]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:52:23 Server CRON[57326]: (root) CMD (test -x /usr/sbin/anacron || { cd / && run-parts --report /etc/cron.daily; })
Jan 15 01:52:23 Server CRON[57335]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:52:23 Server CRON[57324]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:52:23 Server CRON[57336]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:52:23 Server CRON[57330]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:52:23 Server CRON[57333]: (root) CMD ( [ -x /usr/lib/php/sessionclean ] && if [ ! -d /run/systemd/system ]; then /usr/lib/php/sessionclean; fi)
Jan 15 01:52:23 Server CRON[57337]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:52:23 Server CRON[57329]: (root) CMD ( [ -x /usr/lib/php/sessionclean ] && if [ ! -d /run/systemd/system ]; then /usr/lib/php/sessionclean; fi)
Jan 15 01:52:23 Server CRON[57332]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:52:23 Server CRON[57334]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:52:23 Server CRON[57331]: (root) CMD ( [ -x /usr/lib/php/sessionclean ] && if [ ! -d /run/systemd/system ]; then /usr/lib/php/sessionclean; fi)
Jan 15 01:52:23 Server CRON[57338]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:52:23 Server CRON[57339]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:52:23 Server CRON[57340]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:52:23 Server CRON[57341]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:52:23 Server CRON[57342]: (root) CMD (cd / && run-parts --report /etc/cron.hourly)
Jan 15 01:52:23 Server CRON[57344]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:52:23 Server CRON[57343]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:52:23 Server CRON[57309]: pam_unix(cron:session): session closed for user root
Jan 15 01:52:23 Server CRON[57251]: pam_unix(cron:session): session closed for user root
Jan 15 01:52:23 Server CRON[57278]: pam_unix(cron:session): session closed for user root
Jan 15 01:52:24 Server systemd[1]: Stopping Network Time Synchronization...
Jan 15 01:52:24 Server systemd[1]: systemd-timesyncd.service: Succeeded.
Jan 15 01:52:24 Server systemd[1]: Stopped Network Time Synchronization.
Jan 15 01:52:24 Server systemd[1]: systemd-timesyncd.service: Consumed 48.219s CPU time.
Jan 15 01:52:24 Server CRON[57288]: pam_unix(cron:session): session closed for user root
Jan 15 01:52:25 Server systemd[1]: phpsessionclean.service: Succeeded.
Jan 15 01:52:25 Server systemd[1]: Finished Clean php session files.
Jan 15 01:52:25 Server runuser[57570]: pam_unix(runuser:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:25 Server runuser[57570]: pam_unix(runuser:session): session closed for user www-data
Jan 15 01:52:25 Server runuser[57574]: pam_unix(runuser:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:52:26 Server runuser[57574]: pam_unix(runuser:session): session closed for user www-data
Jan 15 01:52:26 Server CRON[57295]: pam_unix(cron:session): session closed for user root
Jan 15 01:52:29 Server CRON[57252]: pam_unix(cron:session): session closed for user www-data
Jan 15 01:52:29 Server CRON[57285]: pam_unix(cron:session): session closed for user www-data
Jan 15 01:52:29 Server CRON[57310]: pam_unix(cron:session): session closed for user www-data
Jan 15 01:52:29 Server CRON[57319]: pam_unix(cron:session): session closed for user www-data
Jan 15 01:52:29 Server CRON[57271]: pam_unix(cron:session): session closed for user www-data
Jan 15 01:52:29 Server CRON[57296]: pam_unix(cron:session): session closed for user www-data
Jan 15 01:52:29 Server CRON[57275]: pam_unix(cron:session): session closed for user www-data
Jan 15 01:52:29 Server CRON[57301]: pam_unix(cron:session): session closed for user www-data
Jan 15 01:52:29 Server CRON[57305]: pam_unix(cron:session): session closed for user www-data
Jan 15 01:52:29 Server CRON[57315]: pam_unix(cron:session): session closed for user www-data
Jan 15 01:52:29 Server CRON[57256]: pam_unix(cron:session): session closed for user www-data
Jan 15 01:52:29 Server CRON[57290]: pam_unix(cron:session): session closed for user www-data
Jan 15 01:52:30 Server CRON[57258]: pam_unix(cron:session): session closed for user www-data
Jan 15 01:52:30 Server CRON[57243]: pam_unix(cron:session): session closed for user www-data
Jan 15 01:52:30 Server CRON[57280]: pam_unix(cron:session): session closed for user www-data
Jan 15 01:55:02 Server CRON[57710]: pam_unix(cron:session): session opened for user www-data(uid=33) by (uid=0)
Jan 15 01:55:02 Server CRON[57711]: (www-data) CMD (php /var/www/nextcloud/cron.php)
Jan 15 01:55:03 Server CRON[57710]: pam_unix(cron:session): session closed for user www-data
Jan 15 01:56:25 Server CRON[57209]: pam_unix(cron:session): session closed for user www-data