MB-53077 Merge cheshire-cat into neo

        Mad-Hatter:
             - MB-53077 Add support for memory threshold alert

Change-Id: I7232b2ab3a128da881c18cf324c0280e6e0bceb8

Author: timofey-barmin

cbmgr.py

@@ -2256,6 +2256,8 @@ def __init__(self):
                                                      "node")
         group.add_argument("--alert-disk-analyzer", dest="alert_disk_analyzer", action="store_true",
                            help="Alert when the disk analyzer gets stuck")
+        group.add_argument("--alert-memory-threshold", dest="alert_memory_threshold",
+                           action="store_true", help="Alert when system memory usage exceeds threshold")
 
     @rest_initialiser(cluster_init_check=True, version_check=True)
     def execute(self, opts):
@@ -2302,6 +2304,8 @@ def execute(self, opts):
             alerts.append('time_out_of_sync')
         if opts.alert_disk_analyzer:
             alerts.append('disk_usage_analyzer_stuck')
+        if opts.alert_memory_threshold:
+            alerts.append('memory_threshold')
 
         enabled = "true"
         if opts.enabled == "0":

docs/modules/cli/pages/cbcli/couchbase-cli-setting-alert.adoc

@@ -24,6 +24,7 @@ _couchbase-cli setting-alert_ [--cluster <url>] [--username <user>] [--password
     [--alert-meta-overhead] [--alert-meta-oom] [--alert-write-failed]
     [--alert-audit-msg-dropped] [--alert-indexer-max-ram]
     [--alert-timestamp-drift-exceeded] [--alert-node-time] [--alert-disk-analyzer]
+    [--alert-memory-threshold]
 
 == DESCRIPTION
 
@@ -137,6 +138,10 @@ include::{partialsdir}/cbcli/part-common-options.adoc[]
   Specifies that an email alert should be sent if the disk analyzer process
   gets stuck and cannot fetch disk usage data.
 
+--alert-memory-threshold::
+  Specifies that an email alert should be sent when any node's system memory
+  usage exceeds a threshold
+
 include::{partialsdir}/cbcli/part-host-formats.adoc[]
 
 include::{partialsdir}/cbcli/part-certificate-authentication.adoc[]
@@ -167,7 +172,7 @@ following command below:
    --alert-ip-changed --alert-disk-space --alert-meta-overhead \
    --alert-meta-oom --alert-write-failed --alert-audit-msg-dropped \
    --alert-indexer-max-ram --alert-timestamp-drift-exceeded \
-   --alert-node-time --alert-disk-analyzer
+   --alert-node-time --alert-disk-analyzer --alert-memory-threshold
 
 To disable email alerts run the following command: