diff --git a/source/includes/5.0-default-wc.rst b/source/includes/5.0-default-wc.rst index 3f51810d3df..65a5befaa29 100644 --- a/source/includes/5.0-default-wc.rst +++ b/source/includes/5.0-default-wc.rst @@ -1,7 +1,8 @@ -Starting in MongoDB 5.0, the implicit default write concern is +Starting in MongoDB 5.0, the implicit default +:ref:`write concern ` is :writeconcern:`w: majority <"majority">`. However, special -considerations are made for deployments containing :ref:`arbiters -`: +considerations are made for deployments containing +:ref:`arbiters `: - The voting majority of a replica set is 1 plus half the number of voting members, rounded down. If the number of data-bearing voting @@ -34,10 +35,10 @@ default write concerns: - Majority of Voting Nodes - Implicit Default Write Concern - * - 3 + * - 2 - 1 - - 4 - 3 + - 2 - ``{ w: 1 }`` * - 4 @@ -46,14 +47,26 @@ default write concerns: - 3 - ``{ w: "majority" }`` -- The first example has 3 non-arbiters and 1 arbiter for a total of 4 - voting nodes. The majority of voting nodes (1 plus half of 4) is 3. - The number of non-arbiters (3) is less than or equal to the majority - of voting nodes, resulting in an implicit write concern of - ``{ w: 1 }``. +- In the first example: -- The second example has 4 non-arbiters and 1 arbiter for a total of 5 - voting nodes. The majority of voting nodes (1 plus half of 5, rounded - down) is 3. The number of non-arbiters (4) is greater than the majority - of voting nodes, resulting in an implicit write concern of ``{ w: - "majority" }``. + - There are 2 non-arbiters and 1 arbiter for a total of 3 voting + nodes. + + - The majority of voting nodes (1 plus half of 3, rounded + down) is 2. + + - The number of non-arbiters (2) is equal to + the majority of voting nodes (2), resulting in an implicit write + concern of ``{ w: 1 }``. + +- In the second example: + + - There are 4 non-arbiters and 1 arbiter for a total of 5 + voting nodes. + + - The majority of voting nodes (1 plus half of 5, rounded + down) is 3. + + - The number of non-arbiters (4) is greater than the majority + of voting nodes (3), resulting in an implicit write concern of + ``{ w: "majority" }``. diff --git a/source/release-notes/5.0.txt b/source/release-notes/5.0.txt index 49b1c5f31e3..31cb7d39564 100644 --- a/source/release-notes/5.0.txt +++ b/source/release-notes/5.0.txt @@ -667,20 +667,20 @@ Implicit Default Write Concern .. include:: /includes/5.0-default-wc.rst -The ``{ w: "majority" }`` default :doc:`write concern -` provides a stronger durability guarantee in -the event of an election, or if replica set members become unavailable. - -The :writeconcern:`w: majority <"majority">` write concern may impact -performance since writes will only be acknowledged once a -:ref:`calculated majority ` of replica set -members have executed and persisted the write to disk. - -If your application relies on performance-sensitive writes, you can use -the :dbcommand:`setDefaultRWConcern` command to explicitly set the -default write concern for improved performance at the cost of data -durability guarantees. You can also set the write concern at the -individual operation level for performance-critical writes. See your +The :writeconcern:`{ w: "majority" } <"majority">` default +:doc:`write concern ` provides a stronger +durability guarantee in the event of an election, or if replica set +members become unavailable. + +The :writeconcern:`{ w: "majority" } <"majority">` write concern may +impact performance since writes will only be acknowledged once a +:ref:`calculated majority ` of replica set +members have executed and persisted the write to disk. If your +application relies on performance-sensitive writes, you can use the +:dbcommand:`setDefaultRWConcern` command to explicitly set the default +write concern for improved performance at the cost of data durability +guarantees. You can also set the write concern at the individual +operation level for performance-critical writes. See your :driver:`driver documentation ` for details. ``mongosShutdownTimeoutMillisForSignaledShutdown`` Parameter