From 4ba7c7c1e054c9f1785bd3ccb8b936e6570919c3 Mon Sep 17 00:00:00 2001
From: Brian Moss <kallimachos@gmail.com>
Date: Fri, 8 Dec 2017 16:00:27 +1000
Subject: [PATCH 1/2] DOCS-8981: Document maxLogSizeKB parameter

Also fix two minor typos.
---
 source/reference/command/setParameter.txt |  1 +
 source/reference/parameters.txt           | 24 +++++++++++++++++++++--
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/source/reference/command/setParameter.txt b/source/reference/command/setParameter.txt
index d9cf3d96c38..fb38a68c42b 100644
--- a/source/reference/command/setParameter.txt
+++ b/source/reference/command/setParameter.txt
@@ -34,6 +34,7 @@ setParameter
    - :parameter:`logComponentVerbosity`
    - :parameter:`logLevel`
    - :parameter:`logUserIds`
+   - :parameter:`maxLogSizeKB`
    - :parameter:`quiet`
    - :parameter:`traceExceptions`
 
diff --git a/source/reference/parameters.txt b/source/reference/parameters.txt
index 2599e758c28..bdabcfd5348 100644
--- a/source/reference/parameters.txt
+++ b/source/reference/parameters.txt
@@ -736,6 +736,26 @@ Logging Parameters
 
    Disabled by default.
 
+.. parameter:: maxLogSizeKB
+
+   .. versionadded:: 3.4
+
+   |both|
+
+   *Type*: integer
+
+   *Default*: 10
+
+   Specifies the maximum size, in kilobytes, for a log line. Lines exceeding
+   this limit print only the beginning and end of the line, excising the middle
+   portion.
+
+   For example, the following sets the maximum size to ``20`` kilobytes:
+
+   .. code-block:: sh
+
+      mongod --setParameter maxLogSizeKB=20
+
 .. parameter:: quiet
 
    |both|
@@ -846,7 +866,7 @@ The following parameters support :term:`diagnostic data capture (FTDC)
 
    |mongos-only|
 
-   Specify the the directory for the diagnostic directory for
+   Specify the directory for the diagnostic directory for
    :program:`mongos`. If the directory does not exist,
    :program:`mongos` creates the directory.
 
@@ -882,7 +902,7 @@ The following parameters support :term:`diagnostic data capture (FTDC)
    *Default*: 200
 
    Specifies the maximum size, in megabytes, of the ``diagnostic.data``
-   directory . If directory size exceeds this number, the oldest
+   directory. If directory size exceeds this number, the oldest
    :ref:`diagnostic files in the directory
    <3.2-diagnostic-data-capture>` are automatically deleted based on
    the timestamp in the file name.

From 822707e16138445ccd80b83a9eadad1c5af83b68 Mon Sep 17 00:00:00 2001
From: Brian Moss <kallimachos@gmail.com>
Date: Mon, 11 Dec 2017 16:54:55 +1000
Subject: [PATCH 2/2] DOCS-8981 Add warning for large maxLogSizeKB values

---
 source/reference/parameters.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/source/reference/parameters.txt b/source/reference/parameters.txt
index bdabcfd5348..ade53c2c62d 100644
--- a/source/reference/parameters.txt
+++ b/source/reference/parameters.txt
@@ -756,6 +756,11 @@ Logging Parameters
 
       mongod --setParameter maxLogSizeKB=20
 
+   .. warning::
+
+      Using a large value for :parameter:`maxLogSizeKB` may adversely affect
+      system performance and negatively impact database operations.
+
 .. parameter:: quiet
 
    |both|