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RS: Clarified quorum loss check and warning when activating maintenance mode #1643

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RS: Clarified quorum loss check and warning when activating maintenance mode #1643

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DOC-3587 RS: Clarified quorum loss check and warning when activating …
rrelledge May 30, 2025
9524220
DOC-3587 Adjusted wording of maintenance mode quorum check
rrelledge Jun 2, 2025
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6 changes: 4 additions & 2 deletions content/operate/rs/7.4/clusters/maintenance-mode.md
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Expand Up @@ -17,9 +17,11 @@ Use maintenance mode to prevent data loss during hardware patching or operating

When you activate maintenance mode, Redis Enterprise does the following:

1. Checks whether a shut down of the node will cause quorum loss. If so, maintenance mode will not turn on.
1. Checks whether the cluster has enough active nodes to maintain quorum if one goes down. If taking a node offline would cause quorum loss, maintenance mode will not activate.

Maintenance mode does not protect against quorum loss. If you activate maintenance mode for the majority of nodes in a cluster and restart them simultaneously, quorum is lost, which can lead to data loss.
{{<warning>}}
This check does not consider if other nodes are already in maintenance mode. Do not put the majority of nodes into maintenance mode and restart them simultaneously, as this can cause the cluster to lose quorum and lead to data loss.
{{</warning>}}

1. If no maintenance mode snapshots already exist or if you use `overwrite_snapshot` when you activate maintenance mode, Redis Enterprise creates a new node snapshot that records the node's shard and endpoint configuration.

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6 changes: 4 additions & 2 deletions content/operate/rs/7.8/clusters/maintenance-mode.md
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Original file line number Diff line number Diff line change
Expand Up @@ -17,9 +17,11 @@ Use maintenance mode to prevent data loss during hardware patching or operating

When you activate maintenance mode, Redis Enterprise does the following:

1. Checks whether a shut down of the node will cause quorum loss. If so, maintenance mode will not turn on.
1. Checks whether the cluster has enough active nodes to maintain quorum if one goes down. If taking a node offline would cause quorum loss, maintenance mode will not activate.

Maintenance mode does not protect against quorum loss. If you activate maintenance mode for the majority of nodes in a cluster and restart them simultaneously, quorum is lost, which can lead to data loss.
{{<warning>}}
This check does not consider if other nodes are already in maintenance mode. Do not put the majority of nodes into maintenance mode and restart them simultaneously, as this can cause the cluster to lose quorum and lead to data loss.
{{</warning>}}

1. If no maintenance mode snapshots already exist or if you use `overwrite_snapshot` when you activate maintenance mode, Redis Enterprise creates a new node snapshot that records the node's shard and endpoint configuration.

Expand Down
6 changes: 4 additions & 2 deletions content/operate/rs/clusters/maintenance-mode.md
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -16,9 +16,11 @@ Use maintenance mode to prevent data loss during hardware patching or operating

When you activate maintenance mode, Redis Enterprise does the following:

1. Checks whether a shut down of the node will cause quorum loss. If so, maintenance mode will not turn on.
1. Checks whether the cluster has enough active nodes to maintain quorum if one goes down. If taking a node offline would cause quorum loss, maintenance mode will not activate.

Maintenance mode does not protect against quorum loss. If you activate maintenance mode for the majority of nodes in a cluster and restart them simultaneously, quorum is lost, which can lead to data loss.
{{<warning>}}
This check does not consider if other nodes are already in maintenance mode. Do not put the majority of nodes into maintenance mode and restart them simultaneously, as this can cause the cluster to lose quorum and lead to data loss.
{{</warning>}}

1. If no maintenance mode snapshots already exist or if you use `overwrite_snapshot` when you activate maintenance mode, Redis Enterprise creates a new node snapshot that records the node's shard and endpoint configuration.

Expand Down