下面列出了com.mongodb.DB#command ( ) 实例代码，或者点击链接到github查看源代码，也可以在右侧发表评论。
public static boolean isConfigServer(AbstractMongoDBServer entity) {
LOG.info("Checking if {} is a config server", entity);
MongoClient mongoClient = clientForServer(entity);
try {
DB db = mongoClient.getDB(ADMIN_DB);
CommandResult commandResult = db.command("getCmdLineOpts");
Map<?, ?> parsedArgs = (Map<?, ?>)commandResult.get("parsed");
if (parsedArgs == null) return false;
Boolean configServer = (Boolean)parsedArgs.get("configsvr");
if (configServer != null) {
// v2.5 format
return Boolean.TRUE.equals(configServer);
} else {
// v2.6 format
String role = (String) ((Map)parsedArgs.get("sharding")).get("clusterRole");
return "configsvr".equals(role);
}
} finally {
mongoClient.close();
}
}
public static void testMongoUserId(int max, DB db) {
String collName = "testmongobjid";
DBCollection coll = db.getCollection(collName);
//Setup a sharded collection
BasicDBObject command = new BasicDBObject();
command.put("shardcollection", collName);
DBObject key = new BasicDBObject();
key.put("_id", 1);
command.put("key", key);
command.put("unique", true);
db.command(command);
long startM = System.currentTimeMillis();
for ( int i=0; i<max; i++ ) {
BasicDBObject obj = new BasicDBObject();
obj.put("test", "value-"+i);
coll.save(obj);
}
long endM = System.currentTimeMillis();
System.out.println("Insert " + max + " mongo objectid. time: " + (endM-startM) + " benchmark()");
CommandResult result = db.getStats();
System.out.println(result);
}
/**
* get list of the shards
* @param dbConn
* @return
*/
private static List<String> getShards(DB dbConn) {
List<String> shards = new ArrayList<String>();
DBObject listShardsCmd = new BasicDBObject("listShards", 1);
CommandResult res = dbConn.command(listShardsCmd);
if (!res.ok()) {
LOG.error("Error getting shards for {}: {}", dbConn, res.getErrorMessage());
}
BasicDBList listShards = (BasicDBList) res.get("shards");
//Only get shards for sharding mongo
if (listShards != null) {
ListIterator<Object> iter = listShards.listIterator();
while (iter.hasNext()) {
BasicDBObject shard = (BasicDBObject) iter.next();
shards.add(shard.getString(ID));
}
}
return shards;
}
private boolean isReplSet() {
boolean ret = false;
DB db = new DB(mongoClient, "admin");
CommandResult cr = db.command("replSetGetStatus");
logger.info("isReplSet: {}", cr.toJson());
if (cr.containsField("set") && cr.containsField("members")) {
ret = true;
}
return ret;
}
private boolean isShard() {
boolean ret = false;
DB db = new DB(mongoClient, "admin");
CommandResult cr = db.command("isdbgrid");
logger.info("isShard: {}", cr.toJson());
if (cr.containsField("isdbgrid") && cr.getInt("isdbgrid") == 1) {
ret = true;
}
return ret;
}
public boolean ping() {
MongoClient client = fastClient();
DBObject command = new BasicDBObject("ping", "1");
final DB db = client.getDB("admin");
try {
CommandResult status = db.command(command);
return status.ok();
} catch (MongoException e) {
LOG.warn("Pinging server {} failed with {}", address.getHost(), e);
} finally {
client.close();
}
return false;
}
public void runScript(String script) {
//有个格式化的作用
try {
DB db = database.getDB();
db.command(buildCommand(script));
} catch (Exception e) {
e.printStackTrace();
}
}
public static void testMyUserId(int max, DB db) {
String collName = "testmyuserid";
DBCollection coll = db.getCollection(collName);
//Setup a sharded collection
BasicDBObject command = new BasicDBObject();
command.put("shardcollection", collName);
DBObject key = new BasicDBObject();
key.put("_id", 1);
command.put("key", key);
command.put("unique", true);
db.command(command);
long startM = System.currentTimeMillis();
BasicDBObject obj = new BasicDBObject();
for ( int i=0; i<max; i++ ) {
UserId userId = new UserId("username"+i);
obj.put("_id", userId.getInternal());
obj.put("test", "value-"+i);
coll.save(obj);
}
long endM = System.currentTimeMillis();
System.out.println("Insert " + max + " my objectid. time: " + (endM-startM) + " benchmark()");
CommandResult result = db.getStats();
System.out.println(result);
}
public static void testStringUserId(int max, DB db) {
String collName = "teststringid";
DBCollection coll = db.getCollection(collName);
//Setup a sharded collection
BasicDBObject command = new BasicDBObject();
command.put("shardcollection", collName);
DBObject key = new BasicDBObject();
key.put("_id", 1);
command.put("key", key);
command.put("unique", true);
db.command(command);
long startM = System.currentTimeMillis();
BasicDBObject obj = new BasicDBObject();
for ( int i=0; i<max; i++ ) {
obj.put("_id", "username"+i);
obj.put("test", "value-"+i);
coll.save(obj);
}
long endM = System.currentTimeMillis();
System.out.println("Insert " + max + " my objectid. time: " + (endM-startM) + " benchmark()");
CommandResult result = db.getStats();
System.out.println(result);
}
public static void testBasicBson(int max, DB db) {
String collName = "testbasicbson";
DBCollection coll = db.getCollection(collName);
//Setup a sharded collection
BasicDBObject command = new BasicDBObject();
command.put("shardcollection", collName);
DBObject key = new BasicDBObject();
key.put("_id", 1);
command.put("key", key);
command.put("unique", true);
db.command(command);
long startM = System.currentTimeMillis();
BasicDBObject objKey = new BasicDBObject();
UserId userId = new UserId("username");
objKey.put("_id", userId.getInternal());
BasicDBObject obj = new BasicDBObject();
for ( int i=0; i<max; i++ ) {
obj.put("_id", userId.getInternal());
obj.put("test-"+(i)%10, "value-"+i);
coll.update(objKey, obj, true, false);
}
long endM = System.currentTimeMillis();
System.out.println(collName+ " update " + max + " my objectid. time: " + (endM-startM) + " benchmark(56273)");
CommandResult result = db.getStats();
System.out.println(result);
}
public static void testMapDBObject(int max, DB db) {
String collName = "testmapobject";
DBCollection coll = db.getCollection(collName);
//Setup a sharded collection
BasicDBObject command = new BasicDBObject();
command.put("shardcollection", collName);
DBObject key = new BasicDBObject();
key.put("_id", 1);
command.put("key", key);
command.put("unique", true);
db.command(command);
long startM = System.currentTimeMillis();
BasicDBObject objKey = new BasicDBObject();
UserId userId = new UserId("username");
objKey.put("_id", userId.getInternal());
MapDBObject obj = new MapDBObject();
for ( int i=0; i<max; i++ ) {
obj.put("_id", userId.getInternal());
obj.put("test-"+(i)%10, "value-"+i);
coll.update(objKey, obj, true, false);
}
long endM = System.currentTimeMillis();
System.out.println(collName+ " update " + max + " my objectid. time: " + (endM-startM) + " benchmark(114892)");
CommandResult result = db.getStats();
System.out.println(result);
}
/**
* Pre-split database
* @param shardCollections: the set of collections to be split
* @param dbName
* @param mongoTemplate
* @return Error description, or null if no errors
*/
public static String preSplit(Set<String> shardCollections, String dbName, MongoTemplate mongoTemplate) {
DB dbConn = mongoTemplate.getDb().getSisterDB("admin");
//Don't do anything if it is non-sharded
List<String> shards = getShards(dbConn);
if (shards.size() == 0) {
return null;
}
//set balancer off
String sresult = setBalancerState(dbConn, false);
if (sresult != null) {
return sresult;
}
// Enable sharding for this database
DBObject enableShard = new BasicDBObject("enableSharding", dbName);
CommandResult result = dbConn.command(enableShard);
if (!result.ok()) {
LOG.error("Error enabling sharding on {}: {}", dbConn, result.getErrorMessage());
return result.getErrorMessage();
}
for (String coll : shardCollections) {
String collection = dbName + "." + coll;
// Enable sharding for this collection, sharding on _id
DBObject shardColl = new BasicDBObject();
shardColl.put("shardCollection", collection);
shardColl.put("key", new BasicDBObject(ID, 1));
result = dbConn.command(shardColl);
if (!result.ok()) {
LOG.error("Error enabling shard'ing on {}: {}", collection, result.getErrorMessage());
return result.getErrorMessage();
}
sresult = moveChunks(collection, shards, dbConn);
if (sresult != null) {
return sresult;
}
}
return preSplitBinCollections(dbName, mongoTemplate);
}
private static String preSplitBinCollections(String dbName, MongoTemplate mongoTemplate) {
DB dbConn = mongoTemplate.getDb().getSisterDB("admin");
List<String> shards = getShards(dbConn);
if (shards != null && shards.size() > 0) {
int numShards = shards.size();
List<String> collections = Arrays.asList("recordHash", "deltas");
for (String collectionName: collections) {
LOG.info("Shard count = {}. Setting up sharding config for {}!", numShards, collectionName);
String collection = dbName + "." + collectionName;
DBObject shardColl = new BasicDBObject();
shardColl.put("shardCollection", collection);
shardColl.put("key", new BasicDBObject(ID, 1));
CommandResult result = dbConn.command(shardColl);
if (!result.ok()) {
LOG.error("Error enabling shard'ing on recordHash: {}", result.getErrorMessage());
return result.getErrorMessage();
}
int charOffset = 256 / numShards;
List<byte[]> shardPoints = new ArrayList<byte[]>();
shardPoints.add(null);
for (int shard = 1; shard < numShards; shard++) {
String splitString = Integer.toHexString(charOffset * shard);
if (splitString.length() < 2) {
splitString = "0" + splitString;
}
splitString = splitString + STR_0X38;
byte[] splitPoint = RecordHash.hex2Binary(splitString);
shardPoints.add(splitPoint);
LOG.info("Adding recordHash splitPoint [" + RecordHash.binary2Hex(splitPoint) + "]");
DBObject splitCmd = new BasicDBObject();
splitCmd.put("split", collection);
splitCmd.put("middle", new BasicDBObject(ID, splitPoint));
result = dbConn.command(splitCmd);
if (!result.ok()) {
LOG.error("Error splitting chunk in recordHash: {}", result.getErrorMessage());
return result.getErrorMessage();
}
}
for (int index = 0; index < numShards; index++) {
DBObject moveCommand = new BasicDBObject();
moveCommand.put("moveChunk", collection);
moveCommand.put("find", new BasicDBObject(ID, index == 0 ? "$minkey" : shardPoints.get(index)));
moveCommand.put("to", shards.get(index));
result = dbConn.command(moveCommand);
if (!result.ok()) {
if (!result.getErrorMessage().equals("that chunk is already on that shard")) {
LOG.error("Error moving chunk in recordHash: {}", result.getErrorMessage());
return result.getErrorMessage();
}
}
}
}
} else {
LOG.info("No shards or shard count < 0. Not setting sharding config for recordHash!");
}
return null;
}