Repository of mongodb, redis, mysql
MongoDB is a powerful, flexible, and easy-to-extend general-purpose database MongoDB is written in C++ language and is an open source database system based on distributed file storage. Under high load conditions, adding more nodes can ensure server performance. MongoDB aims to provide scalable, high-performance data storage solutions for WEB applications. MongoDB stores data as a document, and the data structure consists of key-value (key=>value) pairs. MongoDB documents are similar to JSON objects. Field values can contain other documents, arrays, and document arrays . Features of MongoDB: 1. Ease of use MongoDB is written in C++ and is an open source database system based on distributed file storage. It is not a relational database. Under high load conditions, add more More nodes can ensure server performance. MongoDB is a document-oriented database, not a relational database. The main reason for not using the relational type is to obtain better scalability. Of course there are some other benefits. Compared with relational databases, document-oriented databases no longer have “rows” The concept is replaced by a more flexible “document” model. The document-oriented approach is able to work with just one record by embedding documents and arrays in the document to represent complex hierarchical relationships, which…
mysql, redis, mongodb database installation
Install mysql If there is an installation dependency error， you can first update the download source with sudo apt-get update 1. Install the server sudo apt-get install mysql-server Start service sudo service mysql start Stop the service sudo service mysql stop Restart the service sudo service mysql restart Check whether mysql exists in the process ps ajx|grep mysql 2 . MySQL configuration file The configuration file directory is /etc/mysql/mysql.cnf Enter the conf.d directory ，open mysql.cnf，found that there is no configuration Enter the mysql.conf.d directory，Open mysql.cnf，You can see the configuration items The main configuration items are as follows bind- address represents the IP bound to the server，The default is 127.0.0.1port represents the port，The default is 3306 datadir represents the database directory，The default is /var/lib/mysqlgeneral_log_file represents the normal log，The default is / var/log/mysql/mysql.loglog_error represents the error log，The default is /var/log/mysql/error.log 3. Client installation sudo apt-get install mysql-client Connect to database mysql -u username -p password Press ctrl+d or enter the following command to exit quit or exit Install redis 1. Download the installation package wget http://download.redis.io /releases/redis-4.0.9.tar.gz 2. Unzip the package tar xzf redis-4.0.9.tar.gz 3. Move，to the usr/local directory sudo mv ./redis-4.0.9 /usr/local/redis/ 4. Enter the redis directory cd /usr/local/redis/ 5. Generate…
NOSQL learning one: Memcached, Redis, MongoDB differences
Redis is an open source (BSD licensed), in-memory data structure server that can be used as a database, cache, and message queue broker. Memcached is a free and open source, high-performance, distributed memory object caching system. MongoDB is a database based on distributed file storage, a document-type non-relational database, which is different from the above two. 1. Performance: Performance is excellent, right down to the details, because Redis only uses a single core, and Memcached can use multiple cores, so on average Redis on each core has higher performance than Memcached when storing small data. In the data of 100k or more, the performance of Memcached is higher than that of Redis. Although Redis has recently been optimized for the performance of storing big data, it is still slightly inferior to Memcached. The performance of the first two is similar, greater than Mongodb. 2. Memory space and data size: MemCached can modify the maximum memory and adopts the LRU algorithm. Redis adds VM features and breaks through the limitations of physical memory. MongoDB is suitable for the storage of large amounts of data. It relies on the operating system VM for memory management and is also powerful in consuming memory.…
The native APIs of elasticsearch, redis, and mongo, the XXXtemplateAPI of springdata, and the API usage summary that inherits the XXXrepository interface
The API operations of native TransportClient, JedisCluster, and MongoClient are closer to the bottom layer and closer to imperative operations, but the operation is more troublesome. Let’s take a look at how spring data is played ES part：ElasticsearchTemplate holds a reference to TransportClient，enhances its decoration，simplifies the processing of result sets ，There is no need to explicitly assign the value of the model，You only need to pass in the clazz object of the model. It seems easy to operate in a JPA-like manner by inheriting the ElasticsearchCrudRepository interface. It also automatically processes the result set, but I personally think it has the following disadvantages: It specifies the index to be operated through the model annotation, and uses the method name or #64; The query annotation is not suitable for operation when the specified query conditions are complex. The operation is troublesome and error-prone – not suitable for coders who are not familiar with JPA. Recommended ElasticsearchTemplate API，The three postures are compared as follows Add dependencies，Generally, only spring-boot-starter-data-elasticsearchorg.springframework.dataspring-data-elasticsearch3.1.5.RELEASEorg.elasticsearch.clienttransportorg.elasticsearch.pluginx-pack-api6.2.4org.elasticsearch.clientx-pack-transport6.2.4org.elasticsearch.clienttransport6.2.4org.elasticsearchelasticsearch 6.2.4 ES connection configuration classConfigurationpublic class EsClientConfiguration { @Value(“${es.clusterName}”)private String clusterName;@Value(“${es.userName}”)private String userName; @Value(“${es.userPwd}”)private String userPwd;@Value(“${es.clusterNodes}”)private String clusterNodes; @Value(“${es.caPath}”)private String caPath;@Value(“${es.esKey}”)private String esKey; @Value(“${es.certificate}”)private String certificate;@Value(“${es.SSLflag:true}”)private boolean SSLflag;@Beanpublic TransportClient transportClient() throws UnknownHostException {Settings settings…
Nosql database: mongodb, redis, memcached, their advantages, disadvantages and application scenarios?
1.mongodb (1) is a document-type non-relational database, uses the bson structure. The advantage is that the query function is relatively powerful and it can store massive data. The disadvantage is thatComparison consumes memory. (2) Generally can be used to store semi-structured data such as comments, and supports secondary indexing. Suitable for storing json type data that does not change frequently. (3) Example: a. Website data: very suitable for real-time insertion, update, and query; b. Cache: The persistent cache layer it builds can avoid overloading the underlying data sources; c. Used for storage of objects and JSON data: Mongo’s BSON data format is very suitable for storage and query of documented formats; d.High scalability scenarios: Mongo is very suitable for databases consisting of dozens or hundreds of servers; e. Not suitable for banking or accounting systems; f. Common scenarios 2.redis (1) It is an in-memory database. The data is stored in the memory and directly accessed through tcp. The advantage isHigh read and write performance span>. (2)redis is a memory KV database (key-value storage database, its data is based on key-value pairs Organize, index, and store according to the situation), does not support secondary index, supports list, set, etc. Data format.…
Gin project structure_Use go to build efficient restapi service (using postgresql, redis, gin, gorm…)
In this article, we will introduce how to Use go language to build an efficient and stable rest service and how to deploy it. We have already set up the wheels ，The good news is that，it’s all open source，You can fork our project directly ruilisi/go-pangugithub.com ，Thus saving additional development time. Fasten your seat belts – we’re going. （This tutorial may not be the latest，We will update this tutorial in real time in the github project） Efficiency is king Go has two features that allow us to choose to use it to develop back-end rest services. One is Go’s high performance in terms of concurrency. In rest services, most interfaces will have a heavy load. They must withstand thousands of requests per second. Volume and high concurrency performance become a very important factor. Second, the Go language is a strongly typed language. Although it will be a little troublesome during the writing process, it will not bury some implicit bugs, thus ensuring the robustness of the program. At the same time, the “perfect package management” and C-like writing method enable any programmer to quickly switch technology stacks without too much burden. Brief introduction This service uses the following packages/tools in the…
The difference between relational database (RelationalDatabase) and non-relational database (NoSQL): (MySQL, Redis, Memcache, MongoDB)
Table of Contents Relational Database（Relational Database） What is a relational database What is SQL？ The structure of a relational database Relational model Benefits of relational databases Data consistency Isolation and Atomicity ACID and Relational Databases Stored Procedures and Relational Databases Database Locking and Concurrency What to look for when choosing a relational database The relational database of the future Non-relational databases – an introduction to NoSQL What are the types of NoSQL databases？ How NoSQL database works The difference between Nosql and relational database 1. Storage method 2. Storage structure 3. Storage specification 4. Storage expansion 5. Query method 6. Transaction 7. Performance 8. Authorization method ACID theory 1. Atomicity 2. Consistency 3. Isolation 4. Durability Features and differences of Redis，Memcache，MongoDb Redis Advantages Disadvantages Memcache Advantages Disadvantages MongoDB Advantages Disadvantages The difference between Redis, Memcache and MongoDB 1. Performance 2. Convenience 3. Storage Space 4. Availability 5. Reliability 6. Consistency 7. Data analysis 8. Application scenarios Introduction to Redis Advantages of Redis Related NoSQL resources Relational Database（Relational Database） What is a relational database A relational database is a type of database that stores and provides access to data points that are related to each other. Relational databases are based on…
Overview of NoSQL and Memcached, Redis, and MongoDB
1. Introduction to NoSQL Non-relational databases (mysql, oracle, sqlserver are It is a relational database) 1. Features There is no relationship between data, you can expand it at will Data storage Simple, can be stored in memory, and has fast reading and writing speed No need to create tables or fields. Custom format 2. Classification A. Key-Value database: redis, memcached, riak redis/memcached is suitable for storing user information, such as sessions, configuration files, parameters, shopping carts, etc. This information is generally linked to ID (key) B. Document-Oriented database: MongoDB, CouchDB, RavenDB MongoDB stores data in the form of documents. Each document is a collection of a series of data items. Each data item has a name and a corresponding value. The value can be a simple data type. , such as text, strings, numbers, dates, etc., or complex types, such as ordered lists and associated objects. The smallest unit of data storage is a document. The document attributes stored in the same table can be different. The data can be in various forms such as XML, JSON or JSONB C. Column store (Wide Column Store/Column-Family) database:Cassandra, HBase D. Graph-Oriented database: Neo4J, Infinite Graph, OrientDB 2. Introduction to Memcached Overseas Developed…
Linux (Ubuntu) environment construction, basic framework, summary (mongo replica set, redis…)
Save screenshots: The mongo replica set is written separately: 1. Create the corresponding conf file /etc/mongos/mongod1.conf /etc/mongos/mongod2.conf /etc/mongos/mongod3.conf 2. Create corresponding data files /mongodata/data1 /mongodata/data2 /mongodata/data3 3. Start mongo as a replica set (Stop adding –shutdown) Mongod–f /etc/mongos/mongod1.conf –replSetrs1 Mongod–f /etc/mongos/mongod2.conf –replSetrs1 Mongod–f /etc/mongos/mongod3.conf –replSetrs1 4. Log in to one (you hope it is the primary one) mongo 192.168.1.226:27017 User admin cOnfig={ “_id” : “rs1”, “members” : [ “_id” : 0, “host” : “192.168.1.226:27017” }, “_id” : 1, “host” : “192.168.1.226:27017” }, “_id” : 2, “host” : “192.168.1.226:27017” ] } rs.initiate(config) rs.status()//Check the situation Arbitration node Configuration example : “host” : “192.168.1.226:27017”, arbiterOnly: true; The arbiter node can be used as long as you Even if the machine is down, there are still two available
Why can’t I get the picture in the description in mysql? How do mysql, redis, and mongodb implement the “nearby people” function? …
Introduction Yesterday a fan of the public account discussed an interview question with me ， I personally think it is more meaningful， I compiled it here and shared it with you We all hope that friends will avoid pitfalls on the way to interviews. The interview question is relatively simple – “Let you realize the function of a nearby person – what are your plans?” ， This question is actually mainly to test everyone’s breadth of technology – This article introduces several solutions ， gives you some ideas， to avoid being stuck for words during the interview process and affecting the interview results，if there is anything lax， I hope my relatives can correct me gently！ ; The “people nearby” function is commonly used in life – like restaurants near takeout apps and nearby vehicles in shared bicycle apps. Since the probability of being asked questions in common interviews is very high, let’s analyze the “nearby people” function based on mysql database, Redis, and MongoDB in turn. Insert image description here Popular Science：The common way to identify a location in the world is to use longitude and latitude. The range of longitude is (-180, 180] ， The range of latitude is…
