我用来以列表cursor.toArray()的形式返回我collection.find(query)的 API，我的 API 的响应时间为 100 毫秒。提取到游标中的数据非常少（几百条记录），数据库在我正在查询的字段上建立索引。我还设置了批量大小cursor.batchSize(1000)。
db.collection.find({"{ "ZIP" : { "$in" : [ "12345"]}}"}) 是我的查询，我的数据库在 'ZIP' 上被索引。我可以在 4 毫秒内看到在 shell 上运行相同的查询。
mongo shell 上的相同查询几乎不需要 5 毫秒。
我正在使用的 Mogo 驱动程序是：
<!-- https://mvnrepository.com/artifact/org.mongojack/mongojack -->
<dependency>
<groupId>org.mongojack</groupId>
<artifactId>mongojack</artifactId>
<version>2.8.2</version>
</dependency>
编码
@Path("/")
@Produces(MediaType.APPLICATION_JSON)
@Api(value = "listing-mongo")
public class MlsMongoResource {
private JacksonDBCollection<Mlsdatadao, String> collection;
Clock clock;
public MlsMongoResource(JacksonDBCollection<Mlsdatadao, String> collection) {
this.collection = collection;
this.clock = Clock.systemUTC();
}
@GET
@Path("/listings-mongo")
@Produces(value = MediaType.APPLICATION_JSON)
@Timed
public List<Mlsdatadao> getListings(@BeanParam MlsListingParameters mlsBeanParam) {
BasicDBList basicDbList = new BasicDBList();
mlsBeanParam.validateBean();
setLocations(basicDbList,mlsBeanParam.zipcodes);
BasicDBObject query = new BasicDBObject("$and", basicDbList);
DBCursor<Mlsdatadao> cursor = null;
long start = 0;
try{
start = System.currentTimeMillis();
cursor = collection.find(query);
cursor.batchSize(1000);
} catch (Exception e){
System.out.println("IN collection.find() " + e.getCause());
}
System.out.println("QUERY LIST IS " + basicDbList);
if(cursor == null) {
System.out.println("Cursor is null");
}
List<Mlsdatadao> result = cursor.toArray();
cursor.close();(System.currentTimeMillis() - start));
return result;
}
private void setLocations(BasicDBList basicDbList, List<String> zipcodes) {
if (CollectionUtils.isNotEmpty(zipcodes)) {
basicDbList.add(setZipcodes(zipcodes));
}
}
private BasicDBObject setZipcodes(List<String> zipcodes) {
return new BasicDBObject("ZIP" , new BasicDBObject("$in", zipcodes) );
}
}
应用：
public class MongoApplication extends Application <MlsMongoConfiguration> {
public static void main(String[] args) throws Exception {
new MlsMongoApplication().run(args);
}
@Override
public String getName() {
return "mls-dropwizard-mongo";
}
@Override
public void initialize(Bootstrap<MlsMongoConfiguration> bootstrap) {
bootstrap.addBundle(new SwaggerBundle<MlsMongoConfiguration>() {
@Override
protected SwaggerBundleConfiguration getSwaggerBundleConfiguration(MlsMongoConfiguration configuration) {
return configuration.swaggerBundleConfiguration;
}
});
}
@Override
public void run(MlsMongoConfiguration configuration, Environment environment) throws Exception {
MongoClientOptions.Builder clientOptions = new MongoClientOptions.Builder();
clientOptions.minConnectionsPerHost(1000);//min
clientOptions.maxWaitTime(1000);
clientOptions.connectionsPerHost(1000);
//Create Mongo instance
//Mongo mongo = new Mongo(configuration.mongohost, configuration.mongoport);
MongoClient mongoClient = new MongoClient(new ServerAddress(configuration.mongohost, configuration.mongoport), clientOptions.build());
//Add Managed for managing the Mongo instance
//MongoManaged mongoManaged = new MongoManaged(mongo);
MongoManaged mongoManaged = new MongoManaged(mongoClient);
environment.lifecycle().manage(mongoManaged);
//Add Health check for Mongo instance. This will be used from the Health check admin page
environment.healthChecks().register("MongoHealthCheck", new MongoHealthCheck(mongoClient));
//Create DB instance and wrap it in a Jackson DB collection
DB db = mongoClient.getDB(configuration.mongodb);
JacksonDBCollection<Mlsdatadao, String> jacksonDBCollection = JacksonDBCollection.wrap(db.getCollection("mlsdata"), Mlsdatadao.class, String.class);
environment.jersey().register(new MlsMongoResource(jacksonDBCollection));
}
}
有什么办法可以避免cursor.toArray()吗？任何其他性能调整提示都会非常有帮助。
谢谢。