# `DM` Performance Tuning

+ For full data export tuning, configuration item **`mydumpers`**
  + Option **`rows:`** 
    + Maximum number of rows contained in each exported chunk
  + Option **`threads:`** (default: 4) 
    + Number of concurrent threads for processing the exported chunks
  + Option **`chunk-filesize:`** (default: 64 in `MB`)
    + `DM` splits the data of each table into multiple chunks by this size, it will be ignored in case option **`rows`** is also set 
+ For full data import tuning, configuration item **`loaders`**
  + Option **`pool-size:`** (default: 16)
    + Number of concurrent threads in the `DM Load` module
+ For incremental data replication tuning, configuration item **`syncer`**
  + Option **`worker-count:`** (default: 16)
    + Number of threads for concurrent replication of `DML` in the `DM Sync` module
  + Option **`batch:`** (default: 100)
    + Number of `DML` statements in the same transaction during replication

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[no notes]