Add some docs on VTGate buffering for MoveTables and Reshard traffic …

…switching Signed-off-by: Matt Lord <mattalord@gmail.com>
vitessio · Apr 25, 2024 · 2b3fc2c · 2b3fc2c
1 parent 123fcc3
commit 2b3fc2c
Show file tree

Hide file tree

Showing 4 changed files with 21 additions and 1 deletion.
diff --git a/content/en/docs/20.0/concepts/move-tables.md b/content/en/docs/20.0/concepts/move-tables.md
@@ -2,7 +2,7 @@
 title: MoveTables
 ---
 
-MoveTables is a new workflow based on VReplication. It enables you to relocate tables between keyspaces, and therefore physical MySQL instances, without downtime.
+MoveTables is a workflow based on VReplication. It enables you to relocate tables between keyspaces, and therefore physical MySQL instances, without downtime.
 
 ## Identifying Candidate Tables
 

diff --git a/content/en/docs/20.0/reference/features/vtgate-buffering.md b/content/en/docs/20.0/reference/features/vtgate-buffering.md
@@ -83,6 +83,10 @@ outages/fail overs, etc.)
 {{< /warning >}}
 
 
+## What happens during a MoveTables or Reshard SwitchTraffic or ReverseTraffic with Buffering
+
+... TODO
+
 ## How does it work?
 
 The following steps are considerably simplified, but to give a high level

diff --git a/content/en/docs/20.0/reference/vreplication/movetables.md b/content/en/docs/20.0/reference/vreplication/movetables.md
@@ -80,13 +80,21 @@ It is too expensive to get real-time row counts of tables, using _count(*)_, say
 
 [`switchtraffic`](../../programs/vtctldclient/vtctldclient_movetables/vtctldclient_movetables_switchtraffic/) switches traffic forward for the `tablet-types` specified. You can switch all traffic with just one command, and this is the default behavior. Note that you can now switch replica, rdonly, and primary traffic in any order.
 
+{{< info >}}
+Note that VTGate can [buffer queries](../../features/vtgate-buffering/) when switching traffic which can virtually eliminate any visible impact on application users.
+{{</ info >}}
+
 </div>
 
 #### ReverseTraffic
 <div class="cmd">
 
 [`reversetraffic`](../../programs/vtctldclient/vtctldclient_movetables/vtctldclient_movetables_reversetraffic/) switches traffic in the reverse direction for the `tablet-types` specified. The traffic should have been previously switched forward using `SwitchTraffic` for the `cells` and `tablet-types` specified.
 
+{{< info >}}
+Note that VTGate can [buffer queries](../../features/vtgate-buffering/) when switching traffic which can virtually eliminate any visible impact on application users.
+{{</ info >}}
+
 </div>
 
 #### Cancel

diff --git a/content/en/docs/20.0/reference/vreplication/reshard.md b/content/en/docs/20.0/reference/vreplication/reshard.md
@@ -64,13 +64,21 @@ It is too expensive to get real-time row counts of tables, using _count(*)_, say
 
 [`SwitchTraffic`](../../programs/vtctldclient/vtctldclient_movetables/vtctldclient_movetables_switchtraffic) switches traffic forward for the `tablet-types` specified. This replaces the previous `SwitchReads` and `SwitchWrites` commands with a single one. It is now possible to switch all traffic with just one command, and this is the default behavior. Also, you can now switch replica, rdonly and primary traffic in any order: earlier you needed to first `SwitchReads` (for replicas and rdonly tablets) first before `SwitchWrites`.
 
+{{< info >}}
+Note that VTGate can [buffer queries](../../features/vtgate-buffering/) when switching traffic which can virtually eliminate any visible impact on application users.
+{{</ info >}}
+
 </div>
 
 #### ReverseTraffic
 <div class="cmd">
 
 [`ReverseTraffic`](../../programs/vtctldclient/vtctldclient_movetables/vtctldclient_movetables_reversetraffic/) switches traffic in the reverse direction for the `tablet-types` specified. The traffic should have been previously switched forward using `SwitchTraffic` for the `cells` and `tablet_types` specified.
 
+{{< info >}}
+Note that VTGate can [buffer queries](../../features/vtgate-buffering/) when switching traffic which can virtually eliminate any visible impact on application users.
+{{</ info >}}
+
 </div>
 
 #### Cancel