From c670b86ae895a9583df6ab66f9467b546dc0e6d5 Mon Sep 17 00:00:00 2001 From: shannonbradshaw Date: Sat, 17 Mar 2018 17:29:03 -0400 Subject: [PATCH] Update read-concern.txt --- source/reference/read-concern.txt | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/source/reference/read-concern.txt b/source/reference/read-concern.txt index 82f75d0a884..d71892b3618 100644 --- a/source/reference/read-concern.txt +++ b/source/reference/read-concern.txt @@ -136,16 +136,16 @@ The following read concern levels are available: .. versionadded:: 3.6 -MongoDB introduces the ``afterClusterTime`` option that can be set by -the drivers. +MongoDB 3.6 introduces the ``afterClusterTime`` option that can be set by +the drivers. To satisfy a read request with an ``afterClusterTime`` value of ``T`` a mongod must perform the request after its opLog reaches time ``T``. If its opLog has not reached time ``T`` the mongod must wait to service the request. Read operations with a specified ``afterClusterTime`` return data that meet both the :ref:`read concern level ` -requirement and the specified ``afterClusterTime`` requirement. +requirement and the specified ``afterClusterTime`` requirement. .. important:: - Do not manually set the ``afterClusterTime``. MongoDB drivers set + Do not manually set ``afterClusterTime``. MongoDB drivers set this value automatically for operations associated with causally consistent sessions. @@ -160,8 +160,8 @@ and :readconcern:`"majority"` read concern levels: readConcern: { level: <"majority"|"local"> , afterClusterTime: } For read operations not associated with causally consistent sessions, -i.e. where the ``afterClusterTime`` is unset, reads against secondary members -have the default read concern level: :readconcern:`"available"`. +i.e. where ``afterClusterTime`` is unset, reads against secondary members +have the default read concern level: :readconcern:`"available"`, meaning that queries will return the instance’s most recent data. :readconcern:`"available"` provides no guarantee that data has been written to a majority of the replica set members. It might be rolled back. .. _read-concern-storage-engine-drivers: