@@ -11,9 +11,13 @@ Prepare for Cluster Maintenance
11
11
:class: singlecol
12
12
13
13
|mms| performs a :opsmgr:`rolling restart </reference/glossary/#std-term-rolling-restart>` when you perform maintenance
14
- on nodes in a cluster. {+aagent+} updates nodes in a cluster one-by-one
15
- until all nodes are updated to maintain cluster availability during a
16
- maintenance period.
14
+ on nodes in a cluster. To maintain cluster availability during a
15
+ maintenance period, {+aagent+} updates nodes in a cluster in the
16
+ following way:
17
+
18
+ - For three-member replica sets, {+aagent+} updates nodes one node at a
19
+ time.
20
+ - For five-member replica sets, {+aagent+} updates two nodes at a time.
17
21
18
22
Before you perform maintenance on your clusters, review the following
19
23
considerations and take action, if necessary, to maintain cluster
@@ -53,27 +57,19 @@ Fault Tolerance
53
57
---------------
54
58
55
59
Nodes undergoing maintenance don't provide failover support to the
56
- cluster. For three-member replica sets, if an additional node becomes
57
- unavailable while one node is undergoing maintenance, the cluster has
58
- lost the majority of nodes. The primary node loses this status and
60
+ cluster. For three-member and five-member replica sets, if an
61
+ additional node becomes unavailable during maintenance, the cluster
62
+ loses the majority of nodes. The primary node loses this status and
59
63
steps down to become a secondary node. A new primary can't be elected
60
- until a majority of the cluster's nodes are available.
64
+ until a majority of the cluster's nodes become available.
61
65
62
66
For mission-critical applications with high uptime needs, consider
63
- converting a three-member replica set to a five-member replica
64
- set before performing maintenance to maintain cluster majority in case
67
+ :ref:`adding a temporary arbiter <add-member-to-rs>` to a
68
+ three-member or five-member replica set before you perform maintenance.
69
+ The temporary arbiter can maintain cluster majority in case
65
70
an additional cluster node becomes unavailable during a maintenance
66
71
period.
67
72
68
- .. note::
69
-
70
- Five-member replica sets or larger are more resilient and less likely
71
- to experience loss of majority during maintenance periods.
72
-
73
- A simpler but less resilient option to increase multiple failure
74
- tolerance is to :ref:`add a temporary arbiter <add-member-to-rs>` to a
75
- three-member replica set before you perform maintenance.
76
-
77
73
Unique Index Builds
78
74
-------------------
79
75
0 commit comments