MongoDB 查看chunk块大小

使用mongo shell连到mongos
执行命令：AllChunkInfo("dbname.cellname",true)

点击(此处)折叠或打开

AllChunkInfo = function(ns, est){

var chunks = db.getSiblingDB("config").chunks.find({"ns" : ns}).sort({min:1}); //this will return all chunks for the ns ordered by min

//some counters for overall stats at the end

var totalChunks = 0;

var totalSize = 0;

var totalEmpty = 0;

 print("ChunkID,Shard,ChunkSize,ObjectsInChunk"); // header row

// iterate over all the chunks, print out info for each

chunks.forEach(

function printChunkInfo(chunk) {

var db1 = db.getSiblingDB(chunk.ns.split(".")[0]); // get the database we will be running the command against later

var key = db.getSiblingDB("config").collections.findOne({_id:chunk.ns}).key; // will need this for the dataSize call

// dataSize returns the info we need on the data, but using the estimate option to use counts is less intensive

var dataSizeResult = db1.runCommand({datasize:chunk.ns, keyPattern:key, min:chunk.min, max:chunk.max, estimate:est});

// printjson(dataSizeResult); // uncomment to see how long it takes to run and status

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

totalSize += dataSizeResult.size;

totalChunks++;

if (dataSizeResult.size == 0) { totalEmpty++ }; //count empty chunks for summary

 }

)

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)));

}