DOCSP-33482 Default Concurrent Read/Write Transactions (#4953)

* DOCSP-33482 Default Concurrent Read/Write Transactions

* move default below

* JD feedback

* SR feedback

* more fixes

* include replacement

* typo

Author: ajhuh-mdb

source/includes/fact-concurrent-read-write-dynamic-behavior.rst

@@ -0,0 +1,6 @@
+If you use the default value, MongoDB dynamically adjusts the number of tickets 
+to optimize performance, with a highest possible value of 128. 
+   
+Starting in MongoDB 7.0, if you set |wtparam| to a non-default value, it 
+disables an algorithm that dynamically adjusts the number of concurrent storage 
+engine transactions.

source/reference/parameters.txt

@@ -5251,18 +5251,24 @@ WiredTiger Parameters
 
    |mongod-only|
 
+   *Type*: integer 
+    
+   *Default*: 128
+
    Starting in MongoDB 7.0, this parameter is available for all storage 
    engines. In earlier versions, this parameter is available for the 
    WiredTiger storage engine only.
 
    Specify the maximum number of concurrent read transactions (read tickets)
    allowed into the storage engine.
 
-   .. include:: /includes/fact-read-write-concurrency-algorithm.rst
+   .. |wtparam| replace:: ``wiredTigerConcurrentReadTransactions``
+
+   .. include:: /includes/fact-concurrent-read-write-dynamic-behavior.rst
 
    .. code-block:: javascript
 
-      db.adminCommand( { setParameter: 1, wiredTigerConcurrentReadTransactions: <num> } )
+      db.adminCommand( { setParameter: 1, wiredTigerConcurrentReadTransactions: <int> } )
 
    .. seealso::
 
@@ -5274,18 +5280,28 @@ WiredTiger Parameters
 
    |mongod-only|
 
+   *Type*: integer 
+
    Starting in MongoDB 7.0, this parameter is available for all storage 
    engines. In earlier versions, this parameter is available for the 
    WiredTiger storage engine only.
 
    Specify the maximum number of concurrent write transactions allowed
    into the WiredTiger storage engine.
 
-   .. include:: /includes/fact-read-write-concurrency-algorithm.rst
+   By default, MongoDB sets ``wiredTigerConcurrentWriteTransactions`` to 
+   whichever value is higher: 
+   
+   - Number of cores on the machine running MongoDB
+   - 4
+
+   .. |wtparam| replace:: ``wiredTigerConcurrentWriteTransactions``
+
+   .. include:: /includes/fact-concurrent-read-write-dynamic-behavior.rst
 
    .. code-block:: javascript
 
-      db.adminCommand( { setParameter: 1, wiredTigerConcurrentWriteTransactions: <num> } )
+      db.adminCommand( { setParameter: 1, wiredTigerConcurrentWriteTransactions: <int> } )
 
    .. seealso::