DOCS-11940: uri option compressors and zlibcompressionlevel

Kay Kim · kay-kim · commit c2f2b0c3a3c4 · 2018-12-11T16:25:06.000-05:00
diff --git a/source/reference/connection-string.txt b/source/reference/connection-string.txt
@@ -55,13 +55,13 @@ The components of this string are:
 
      - Required. It identifies a server
        address to connect to. It identifies either a hostname, IP
-       address, or UNIX domain socket. 
-       
+       address, or UNIX domain socket.
+
        .. include:: /includes/fact-uri-rs-hostnames.rst
 
        For a sharded cluster, specify the hostname of the
        :binary:`~bin.mongos` instance.
-       
+
 
    * - ``:port1``
 
@@ -153,7 +153,7 @@ DNS SRV record. The driver or :binary:`~bin.mongo` shell will then
 query the DNS for the record to determine which hosts are running the
 :binary:`~bin.mongod` instances.
 
-.. note:: 
+.. note::
 
    Use of the ``+srv`` connection string modifier
    automatically sets the ``ssl`` option to ``true`` for the connection.
@@ -164,9 +164,9 @@ The following example shows a typical connection string for a DNS
 seedlist connection string:
 
 .. code-block:: none
- 
+
    mongodb+srv://server.example.com/
- 
+
 The corresponding DNS configuration might resemble:
 
 .. code-block:: none
@@ -181,7 +181,7 @@ The corresponding DNS configuration might resemble:
    domain (in this example, ``example.com``) as the given hostname. If
    the parent domains and hostname do not match, you will not be able to
    connect.
-  
+
 Like the standard connection string, the DNS seedlist connection string
 supports specifying options as a query string. With a DNS seedlist
 connection string, you can *also* specify the following options via a
@@ -217,14 +217,14 @@ of the DNS entry above.
 .. code-block:: none
 
    mongodb+srv://server.example.com/?connectTimeoutMS=300000&authSource=aDifferentAuthDB
-       
+
 Given the override for the ``authSource``, the equivalent connection
 string in the standard format would be:
 
 .. code-block:: none
 
    mongodb://mongodb1.example.com:27317,mongodb2.example.com:27017/?connectTimeoutMS=300000&replicaSet=mySet&authSource=aDifferentAuthDB
-       
+
 .. note::
    The ``mongodb+srv`` option will fail if there is no available DNS
    with records that correspond to the hostname identified in the
@@ -323,12 +323,74 @@ Connection Options
        timeout, though different drivers might vary. See the
        :ecosystem:`driver </drivers>` documentation.
 
+   * - .. urioption:: compressors
+
+     - Comma-delimited string of compressors to enable
+       network compression for communication between this
+       client and:
+
+       - a :binary:`~bin.mongod` instance
+
+       - a :binary:`~bin.mongos` instance.
+
+       You can specify the following compressors:	
+
+       - :term:`snappy`
+
+       - :term:`zlib` (Available in MongoDB 3.6 or greater)
+
+       If you specify multiple compressors, then the order in which you list
+       the compressors matter as well as the communication initiator. For
+       example, if the client specifies the following network
+       compressors ``"zlib,snappy"`` and the :binary:`~bin.mongod` specifies
+       ``"snappy,zlib"``, messages between the client and the
+       :binary:`~bin.mongod` uses ``zlib``.
+
+       .. important::
+
+          Messages are compressed when both parties enable network
+          compression. Otherwise, messages between the parties are
+          uncompressed.
+
+          If the parties do not share at least one common compressor,
+          messages between the parties are uncompressed.
+
+
+   * - .. urioption:: zlibCompressionLevel
+
+     - An integer that specifies the compression level if using
+       :term:`zlib` for :urioption:`network compression <compressors>`.
+
+       You can specify an integer value ranging from ``-1`` to ``9``:
+
+       .. list-table::
+          :header-rows: 1
+          :widths: 25 75
+
+          * - Value
+            - Notes
+
+          * - ``-1``
+
+            - Default compression level, usually level ``6`` compression.
+
+          * - ``0``
+            - No compression
+
+          * - ``1`` - ``9``
+
+            - Increasing level of compression but at the cost of speed, with:
+
+              - ``1`` providing the best speed but least compression, and
+
+              - ``9`` providing the best compression but at the slowest speed.
+
 .. _connection-pool-options:
 
 Connection Pool Options
 ~~~~~~~~~~~~~~~~~~~~~~~
 
-Most drivers implement some kind of connection pool handling. 
+Most drivers implement some kind of connection pool handling.
 Some drivers do not support connection
 pools. See your :ecosystem:`driver </drivers>` documentation
 for more information on the connection pooling implementation. These
@@ -460,7 +522,7 @@ isolation for their reads from replica sets.
    * - .. urioption:: readConcernLevel
 
      - The level of isolation. Can accept one of the following values:
-     
+
        - :readconcern:`local <"local">`
        - :readconcern:`majority <"majority">`
        - :readconcern:`linearizable <"linearizable">`
@@ -488,8 +550,8 @@ on a per-connection basis in the connection string:
    * - .. urioption:: readPreference
 
      - Specifies the :term:`replica set` read preference for this
-       connection. 
-       
+       connection.
+
        The read preference values are the following:
 
        - :readmode:`primary`
@@ -507,33 +569,33 @@ on a per-connection basis in the connection string:
        .. include:: /includes/extracts/transactions-read-pref.rst
 
    * - .. urioption:: maxStalenessSeconds
-   
+
      - .. versionadded:: 3.4
-     
+
        Specifies, in seconds, how stale a secondary can be before the client
        stops using it for read operations. For details, see:
        :ref:`replica-set-read-preference-max-staleness`.
 
        By default, there is no maximum staleness and clients will not consider a
        secondary's lag when choosing where to direct a read operation.
-  
+
        The minimum :urioption:`maxStalenessSeconds` value is 90
        seconds. Specifying a value between 0 and 90 seconds will produce
        an error. MongoDB drivers treat a ``maxStalenessSeconds`` value
        of ``-1`` as "no max staleness", the same as if
        ``maxStalenessSeconds`` is omitted.
-       
+
        .. important::
           To use ``maxStalenessSeconds``, all of the
           MongoDB instances in your deployment must be using MongoDB 3.4 or
           later. If any instances are on an earlier version of MongoDB, the
           driver or :binary:`~bin.mongos` will raise an error.
-      
+
        The following specifies a maxStalenessSeconds value of 120 seconds
        with the :readmode:`secondary` read preference mode:
-       
+
        .. code-block:: none
-       
+
           mongodb://host.example.com/?readPreference=secondary&maxStalenessSeconds=120
 
    * - .. urioption:: readPreferenceTags
@@ -615,30 +677,30 @@ Authentication Options
    * - .. urioption:: authMechanismProperties
 
      - Specify properties for the specified :urioption:`authMechanism`
-       as a comma-separated list of colon-separated key-value pairs. 
-       For example: 
+       as a comma-separated list of colon-separated key-value pairs.
+       For example:
 
        .. code-block:: shell
           :copyable: false
 
           authMechanismProperties=SERVICE_NAME:mongodb,CANONICALIZE_HOST_NAME:true
 
-       The :urioption:`authMechanismProperties` option is only supported 
-       when :urioption:`authMechanism` is 
+       The :urioption:`authMechanismProperties` option is only supported
+       when :urioption:`authMechanism` is
        :ref:`GSSAPI <security-auth-kerberos>`. Possible values are:
 
        ``SERVICE_NAME:<string>``
          Set the Kerberos service name when connecting to Kerberized
          MongoDB instances. This value must match the service name set
-         on MongoDB instances to which you are connecting. 
+         on MongoDB instances to which you are connecting.
 
-         ``SERVICE_NAME`` defaults to ``mongodb`` for all clients and 
+         ``SERVICE_NAME`` defaults to ``mongodb`` for all clients and
          MongoDB instances. If you change the
          :parameter:`saslServiceName` setting on a MongoDB instance, you
          must set ``SERVICE_NAME`` to match that setting.
 
        ``CANONICALIZE_HOST_NAME:true|false``
-         Canonicalize the hostname of the client host machine when 
+         Canonicalize the hostname of the client host machine when
          connecting to the Kerberos server. This may be required when
          hosts report different hostnames than what is in the Kerberos
          database. Defaults to ``false``.
@@ -660,10 +722,10 @@ Authentication Options
        must set :urioption:`gssapiServiceName` to match that setting.
 
        :urioption:`gssapiServiceName` is a deprecated aliases for
-       :urioption:`authMechanismProperties=SERVICE_NAME:mongodb 
-       <authMechanismProperties>`. For more information on which 
-       options your driver supports and their relative priority to each 
-       other, reference the documentation for your preferred driver 
+       :urioption:`authMechanismProperties=SERVICE_NAME:mongodb
+       <authMechanismProperties>`. For more information on which
+       options your driver supports and their relative priority to each
+       other, reference the documentation for your preferred driver
        version.
 
 .. _selection-discovery-options:
@@ -678,16 +740,16 @@ or write operations.
 .. list-table::
    :header-rows: 1
    :widths: 30 70
-   
+
    * - Connection Option
      - Description
-   
+
    * - .. urioption:: localThresholdMS
 
      - The size (in milliseconds) of the latency window for selecting
        among multiple suitable MongoDB instances. *Default*: 15
        milliseconds.
-       
+
        All drivers use :urioption:`localThresholdMS`. Use the
        ``localThreshold`` alias when specifying the latency window size
        to :binary:`~bin.mongos`.
@@ -706,7 +768,7 @@ or write operations.
        error. When ``false``, the driver blocks and searches for a
        server up to the :urioption:`serverSelectionTimeoutMS` value.
        *Default*: ``true``.
-       
+
        Multi-threaded drivers and :binary:`~bin.mongos` do not support
        :urioption:`serverSelectionTryOnce`.
 
@@ -716,13 +778,13 @@ or write operations.
        checks the state of the MongoDB deployment. Specify the interval
        (in milliseconds) between checks, counted from the end of the
        previous check until the beginning of the next one.
-       
+
        *Default*:
-       
+
        - Single-threaded drivers: 60 seconds.
        - Multi-threaded drivers: 10 seconds.
-       
-       :binary:`~bin.mongos` does not support changing the frequency of 
+
+       :binary:`~bin.mongos` does not support changing the frequency of
        the heartbeat checks.
 
 Miscellaneous Configuration
@@ -736,23 +798,23 @@ Miscellaneous Configuration
      - Description
 
    * - .. urioption:: appName
-   
-     - Specify a custom app name. The app name appears in 
-     
+
+     - Specify a custom app name. The app name appears in
+
        - :binary:`~bin.mongod` and :binary:`~bin.mongos` :doc:`logs
          </reference/log-messages>`,
 
        - the :data:`currentOp.appName` field in the :dbcommand:`currentOp`
          command and :method:`db.currentOp()` method output,
-         
+
        - the :data:`system.profile.appName` field in the :doc:`database
          profiler </reference/database-profiler>` output.
-       
+
        If you do not specify a custom app name, the :binary:`~bin.mongo`
        shell uses the default "``MongoDB Shell``".
-       
+
        .. versionadded:: 4.0
-   
+
    * - .. urioption:: retryWrites
 
      - Enable :ref:`retryable writes <retryable-writes>`.
@@ -830,7 +892,7 @@ UNIX Domain Socket
 ~~~~~~~~~~~~~~~~~~
 
 Use a URL encoded connection string when connecting to a UNIX domain
-socket. 
+socket.
 
 The following connects to a UNIX domain socket with file path
 ``/tmp/mongodb-27017.sock``:
