diff --git a/source/reference/command/moveChunk.txt b/source/reference/command/moveChunk.txt index e28876a77f5..7edcf41b104 100644 --- a/source/reference/command/moveChunk.txt +++ b/source/reference/command/moveChunk.txt @@ -193,5 +193,14 @@ while :dbcommand:`moveChunk` is running, you may see this error. You may retry the :dbcommand:`moveChunk` operation without side effects. +``maxCatchUpPercentageBeforeBlockingWrites`` Server Parameter +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Starting in MongoDB 4.0.26, you can set the +:parameter:`maxCatchUpPercentageBeforeBlockingWrites` to specify the +maximum allowed percentage of data not yet migrated +during a :dbcommand:`moveChunk` operation when compared to the +total size (in MBs) of the chunk being transferred. + .. admin-only diff --git a/source/reference/parameters.txt b/source/reference/parameters.txt index e87b81d24e2..4a01c948980 100644 --- a/source/reference/parameters.txt +++ b/source/reference/parameters.txt @@ -1807,6 +1807,8 @@ Sharding Parameters .. parameter:: AsyncRequestsSenderUseBaton + .. versionadded:: 4.0 + Type: boolean Default: true @@ -1818,7 +1820,39 @@ Sharding Parameters .. seealso:: :parameter:`taskExecutorPoolSize` - .. versionadded:: 4.0 +.. parameter:: maxCatchUpPercentageBeforeBlockingWrites + + .. versionadded:: 4.0.26 + + Type: integer + + Default: 10 + + |mongod-only| + + For :dbcommand:`moveChunk` operations, specifies the maximum + percentage of untrasferred data allowed by the migration protocol + (expressed in percentage of the total chunk size) to + transition from the ``catchup`` phase to the ``commit`` phase. + + Setting a higher catchup percentage can decrease the amount of time + it takes for the migration to complete at the cost of increased + latency during concurrent :method:`upsert ` + and :method:`delete ` operations. + + For example, to set the maximum percentage to 20, you can issue the + followingduring startup: + + .. code-block:: bash + + mongod --setParameter maxCatchUpPercentageBeforeBlockingWrites=20 + + You cannot change + :parameter:`maxCatchUpPercentageBeforeBlockingWrites` during runtime. + + .. seealso:: + + `Live Migration Protocol `__ .. parameter:: replMonitorMaxFailedChecks diff --git a/source/tutorial/migrate-chunks-in-sharded-cluster.txt b/source/tutorial/migrate-chunks-in-sharded-cluster.txt index 8f8d79d5d1a..5aad46268bf 100644 --- a/source/tutorial/migrate-chunks-in-sharded-cluster.txt +++ b/source/tutorial/migrate-chunks-in-sharded-cluster.txt @@ -1,3 +1,5 @@ +.. _migrate-chunks-sharded-cluster: + =================================== Migrate Chunks in a Sharded Cluster ===================================