manyi/script/db/utils.js

SplitChunks = function (ns, shard_name, est) {
    var nextRound = false;
    do {
        nextRound = false;

        var chunks = db.getSiblingDB("config").chunks.find({"ns": ns, "shard": shard_name}).sort({min: 1});
        var totalChunks = 0;
        var totalSize = 0;
        var totalEmpty = 0;

        print("ChunkID,Shard,ChunkSize,ObjectsInChunk");

        chunks.forEach(
            function printChunkInfo(chunk) {
                var db1 = db.getSiblingDB(chunk.ns.split(".")[0]);
                var key = db.getSiblingDB("config").collections.findOne({_id: chunk.ns}).key;
                var dataSizeResult = db1.runCommand({
                    datasize: chunk.ns,
                    keyPattern: key,
                    min: chunk.min,
                    max: chunk.max,
                    estimate: est
                })

                print(chunk._id + "," + chunk.shard + "," + dataSizeResult.size + "," + dataSizeResult.numObjects);

                totalSize += dataSizeResult.size;
                totalChunks++;
                if (dataSizeResult.size == 0) {
                    totalEmpty++;
                }

                if (dataSizeResult.size >= 83886080) {
                    print(chunk.ns + " is too big to split.");
                    sh.splitFind(chunk.ns, chunk.min);
                    nextRound = true;
                }
            }
        )

        print("***********Summary Chunk Information***********");
        print("Total Chunks: " + totalChunks);
        print("Average Chunk Size (bytes): " + (totalSize / totalChunks));
        print("Empty Chunks: " + totalEmpty);
        print("Average Chunk Size (non-empty): " + (totalSize / (totalChunks - totalEmpty)));
    } while (nextRound)
}

SplitChunks("report_his.ConsumeRecord", "shard2", true)