いつもお世話になっております。

Zabbixサーバのメモリ使用率が80%超過しており、psコマンドで確認したところ、
zabbix_serverプロセスのメモリ使用量が一番高いことが分かりました。
また、10月に元々取得不可となっていた約12000のアイテムを以下キーに修正し、ステータス有効にしておりますが、
この作業以降、メモリ使用率が徐々に増加している状況を確認しております。
メモリ使用率が逼迫している原因及び解決方法ございましたら、ご教示のほどよろしくお願いいたします。

■修正アイテムキー
system.run[RESULT=$((tail -1 /xxx/xxx.log.`date +'%Y%m%d%H' -d1hour+ago` 2>/dev/null ; tail -1 /xxx/xxx.log.`date +'%Y%m%d%H'` 2>/dev/null) |tail -1);echo $RESULT 0]

■Zabbixバージョン
zabbix_server:2.2.2
zabbix_agent:2.2.2

■ダッシュボード
Zabbixサーバーの起動 はい localhost:10051
ホスト数 (有効/無効/テンプレート) 755 448 / 254 / 53
アイテム数 (有効/無効/取得不可) 21486 21259 / 164 / 63
トリガー数 (有効/無効) [障害/正常] 31273 30565 / 708 [208 / 30357]
ユーザー数 (オンライン) 16 2
1秒あたりの監視項目数(Zabbixサーバーの要求パフォーマンス) 2429.57 -

■psコマンド結果(VSZで降順ソート)
zabbix 8095 0.0 10.7 1371712 868828 ? S Apr13 276:30 zabbix_server: trapper #5 [processed data in 0.000290 sec, waiting for connection]
zabbix 8099 0.0 10.7 1369816 866992 ? S Apr13 276:38 zabbix_server: trapper #9 [processed data in 0.000383 sec, waiting for connection]
zabbix 8094 0.0 10.7 1369376 866556 ? S Apr13 276:57 zabbix_server: trapper #4 [processed data in 0.000311 sec, waiting for connection]
zabbix 8097 0.0 10.7 1369096 866132 ? S Apr13 276:32 zabbix_server: trapper #7 [processed data in 0.001370 sec, waiting for connection]
zabbix 8098 0.0 10.7 1366288 863424 ? S Apr13 275:18 zabbix_server: trapper #8 [processed data in 0.007616 sec, waiting for connection]
zabbix 8100 0.0 10.6 1364972 862044 ? S Apr13 275:30 zabbix_server: trapper #10 [processed data in 0.000266 sec, waiting for connection]
zabbix 8096 0.0 10.6 1364372 861468 ? S Apr13 275:25 zabbix_server: trapper #6 [processed data in 0.000278 sec, waiting for connection]
zabbix 8092 0.0 10.6 1362972 860044 ? S Apr13 276:38 zabbix_server: trapper #2 [processed data in 0.000313 sec, waiting for connection]
zabbix 8093 0.0 10.6 1362132 859284 ? S Apr13 273:54 zabbix_server: trapper #3 [processed data in 0.000342 sec, waiting for connection]
zabbix 8091 0.0 10.5 1355296 852364 ? S Apr13 273:08 zabbix_server: trapper #1 [processed data in 0.000347 sec, waiting for connection]
zabbix 8112 0.0 0.1 787900 13788 ? S Apr13 121:37 zabbix_server: housekeeper [deleted 98576 hist/trends, 0 items, 265 events, 0 sessions, 0 alarms, 0 audit items in 133.346484 sec, idle 1 hour(s)]
zabbix 8129 0.0 5.4 777812 440948 ? S Apr13 197:12 zabbix_server: history syncer #4 [synced 0 items in 0.000002 sec, idle 5 sec]
zabbix 8131 0.0 5.4 777676 440384 ? S Apr13 197:01 zabbix_server: history syncer #6 [synced 0 items in 0.000001 sec, idle 5 sec]
zabbix 8130 0.0 5.4 777676 440840 ? S Apr13 199:04 zabbix_server: history syncer #5 [synced 0 items in 0.000002 sec, idle 5 sec]
zabbix 8132 0.0 5.4 777672 440344 ? S Apr13 197:18 zabbix_server: history syncer #7 [synced 204 items in 0.310462 sec, idle 5 sec]
zabbix 8128 0.0 5.4 777664 440836 ? S Apr13 197:10 zabbix_server: history syncer #3 [synced 3 items in 0.016393 sec, idle 5 sec]
zabbix 8127 0.0 5.4 777640 440480 ? S Apr13 197:19 zabbix_server: history syncer #2 [synced 602 items in 0.684027 sec, idle 5 sec]
zabbix 8134 0.0 5.4 777508 440356 ? S Apr13 196:55 zabbix_server: history syncer #9 [synced 2 items in 0.011816 sec, idle 5 sec]
zabbix 8135 0.0 5.4 777468 440656 ? S Apr13 197:28 zabbix_server: history syncer #10 [synced 3 items in 0.014603 sec, idle 5 sec]
zabbix 8133 0.0 5.4 777448 440624 ? S Apr13 197:06 zabbix_server: history syncer #8 [synced 0 items in 0.000002 sec, idle 5 sec]
zabbix 8126 0.0 5.4 777300 439532 ? S Apr13 197:31 zabbix_server: history syncer #1 [synced 1 items in 0.012492 sec, idle 5 sec]
zabbix 8118 0.0 1.5 777084 122680 ? S Apr13 290:09 zabbix_server: timer #6 [processed 570 triggers, 0 events in 0.633898 sec, idle 30 sec]
zabbix 8116 0.0 1.3 777060 106756 ? S Apr13 259:58 zabbix_server: timer #4 [processed 571 triggers, 0 events in 0.548631 sec, idle 29 sec]
zabbix 8120 0.0 1.3 777056 105760 ? S Apr13 273:05 zabbix_server: timer #8 [processed 583 triggers, 0 events in 0.746194 sec, idle 29 sec]
zabbix 8122 0.0 1.3 777040 112792 ? S Apr13 257:53 zabbix_server: timer #10 [processed 554 triggers, 0 events in 0.619224 sec, idle 29 sec]
zabbix 8114 0.0 1.5 777036 121668 ? S Apr13 260:12 zabbix_server: timer #2 [processed 566 triggers, 0 events in 0.628407 sec, idle 29 sec]
zabbix 8136 0.0 0.2 776628 22836 ? S Apr13 13:55 zabbix_server: escalator [processed 0 escalations in 0.000497 sec, idle 3 sec]
zabbix 8090 0.0 0.1 776596 13132 ? S Apr13 4:57 zabbix_server: unreachable poller #1 [got 0 values in 0.000005 sec, idle 5 sec]
zabbix 8089 0.1 3.4 776596 275640 ? S Apr13 440:18 zabbix_server: poller #10 [got 8 values in 0.051892 sec, idle 1 sec]
zabbix 8088 0.1 3.4 776596 275608 ? S Apr13 440:30 zabbix_server: poller #9 [got 13 values in 0.053670 sec, idle 1 sec]
zabbix 8087 0.1 3.4 776596 275656 ? S Apr13 440:26 zabbix_server: poller #8 [got 10 values in 0.036648 sec, idle 1 sec]
zabbix 8086 0.1 3.4 776596 275660 ? S Apr13 440:21 zabbix_server: poller #7 [got 12 values in 0.042847 sec, idle 1 sec]
zabbix 8085 0.1 3.4 776596 275612 ? S Apr13 440:08 zabbix_server: poller #6 [got 8 values in 0.044757 sec, idle 1 sec]
zabbix 8084 0.1 3.4 776596 275588 ? S Apr13 440:47 zabbix_server: poller #5 [got 9 values in 0.041012 sec, idle 1 sec]
zabbix 8083 0.1 3.4 776596 275580 ? S Apr13 440:46 zabbix_server: poller #4 [got 14 values in 0.036979 sec, idle 1 sec]
zabbix 8082 0.1 3.4 776596 275632 ? S Apr13 440:48 zabbix_server: poller #3 [got 14 values in 0.041189 sec, idle 1 sec]
zabbix 8081 0.1 3.4 776596 275608 ? S Apr13 441:04 zabbix_server: poller #2 [got 0 values in 0.000004 sec, idle 1 sec]
zabbix 8080 0.1 3.4 776596 275636 ? S Apr13 441:11 zabbix_server: poller #1 [got 7 values in 0.037363 sec, idle 1 sec]
zabbix 8111 0.0 0.0 776568 2288 ? S Apr13 1:30 zabbix_server: alerter [sent alerts: 0 success, 0 fail in 0.000748 sec, idle 30 sec]
zabbix 8125 0.0 0.0 776492 2876 ? S Apr13 0:49 zabbix_server: discoverer #1 [processed 0 rules in 0.000891 sec, idle 60 sec]
zabbix 8115 0.1 1.3 776344 111668 ? S Apr13 363:58 zabbix_server: timer #3 [processed 1133 triggers, 0 events in 1.251510 sec, idle 29 sec]
zabbix 8121 0.1 1.3 776308 109036 ? S Apr13 341:33 zabbix_server: timer #9 [processed 1129 triggers, 0 events in 1.170893 sec, idle 29 sec]
zabbix 8119 0.1 1.5 776308 121760 ? S Apr13 341:43 zabbix_server: timer #7 [processed 1125 triggers, 0 events in 1.056758 sec, idle 28 sec]
zabbix 8117 0.1 1.3 776308 106792 ? S Apr13 349:56 zabbix_server: timer #5 [processed 1132 triggers, 0 events in 1.099256 sec, idle 29 sec]
zabbix 8113 0.1 1.5 776300 122352 ? S Apr13 380:43 zabbix_server: timer #1 [processed 1123 triggers, 0 events in 1.174839 sec, 0 maint.periods in 0.000000 sec, idle 29 sec]
zabbix 8108 0.0 1.7 776192 139396 ? S Apr13 37:04 zabbix_server: icmp pinger #8 [pinging hosts]
zabbix 8105 0.0 1.7 776192 139404 ? S Apr13 37:01 zabbix_server: icmp pinger #5 [pinging hosts]
zabbix 8110 0.0 1.7 776188 139412 ? S Apr13 37:01 zabbix_server: icmp pinger #10 [got 0 values in 0.000004 sec, idle 1 sec]
zabbix 8109 0.0 1.7 776188 139392 ? S Apr13 36:54 zabbix_server: icmp pinger #9 [got 0 values in 0.000004 sec, idle 1 sec]
zabbix 8107 0.0 1.7 776188 139420 ? S Apr13 37:06 zabbix_server: icmp pinger #7 [got 0 values in 0.000004 sec, idle 1 sec]
zabbix 8106 0.0 1.7 776188 139404 ? S Apr13 37:10 zabbix_server: icmp pinger #6 [got 0 values in 0.000004 sec, idle 1 sec]
zabbix 8104 0.0 1.7 776188 139400 ? S Apr13 37:10 zabbix_server: icmp pinger #4 [got 0 values in 0.000011 sec, idle 1 sec]
zabbix 8103 0.0 1.7 776188 139384 ? S Apr13 37:09 zabbix_server: icmp pinger #3 [got 0 values in 0.000004 sec, idle 1 sec]
zabbix 8102 0.0 1.7 776188 139384 ? S Apr13 36:46 zabbix_server: icmp pinger #2 [got 0 values in 0.000004 sec, idle 1 sec]
zabbix 8101 0.0 1.7 776188 139396 ? S Apr13 37:11 zabbix_server: icmp pinger #1 [got 0 values in 0.000004 sec, idle 1 sec]
zabbix 8137 0.0 0.0 775832 1448 ? S Apr13 12:58 zabbix_server: self-monitoring [processed data in 0.000005 sec, idle 1 sec]
zabbix 8124 0.0 0.0 775832 1672 ? S Apr13 10:02 zabbix_server: http poller #1 [got 0 values in 0.000615 sec, idle 5 sec]
zabbix 8123 0.0 0.0 775832 1636 ? S Apr13 1:18 zabbix_server: node watcher [synced with nodes in 0.000001 sec, idle 10 sec]
zabbix 8079 0.0 0.0 775832 1668 ? S Apr13 1:50 zabbix_server: db watchdog [synced alerts config in 0.002188 sec, idle 60 sec]
zabbix 8078 0.2 0.5 775832 44752 ? S Apr13 851:02 zabbix_server: configuration syncer [synced configuration in 2.002805 sec, idle 60 sec]