Programmer Group

summary         In our daily work, we often encounter the need to extract the information in xml files and convert it into entity classes. Combined with our own work experience, we make the following summary, which is convenient for people and ourselves. Code example xml format: <?xml version="1.0" encoding="utf-8"?& ...

High Availability HA (High Availability) is one of the factors that must be considered in the architecture design of distributed systems. It usually refers to reducing the time when the system cannot provide services through design. Assuming that the system can always provide services, we say that the availability of the system is 100%. If the ...

1. Set log Logs can facilitate our troubleshooting. They are not enabled by default. They need to be set in the core configuration file. name and value should be consistent with the official documents! 1.1 default log <!--Set log default configuration--> <settings> <setting name="logImpl" value="STDOUT_LOGGING"/&gt ...

Title: submit sql script file with flynk sql client Date: twenty 21-10-22 22:11:34 Tag: [Flink, SQL client] Category: flink We know that sql-client.sh can provide us with an SQL interactive interface, so that we can see the execution results or interactive query table results without executing an SQL. In fact, we can also submit sql scripts t ...

preface When creating a table, you can add corresponding constraints to the fields of the table. The purpose of adding constraints is to ensure the legitimacy, validity and integrity of the data in the table. Common constraints nameexplainNon NULL constraint (not null)The field of the constraint cannot be NULLUnique constraintConstrained ...

MySQL advanced - Notes - 01 Video of this article: Dark horse MySQL advanced 1, MySQL architecture 1-1 overview of MySQL architecture The entire MySQL Server consists of the following components: Connection Pool: Connection Pool componentManagement services & Utilities: management services and tools componentsSQL interface: SQL i ...

Neo4j - CQL introduction Neo4j's Cypher language is built to process graphic data, and CQL stands for Cypher query language. Like Oracle database with query language SQL, neo4j has CQL as query language It is the query language of Neo4j graphics databaseIs a declarative pattern matching languageFollow SQL syntaxGrammar is a very simple, h ...

preface         After migrating a single application to a distributed framework, it is likely to encounter such a problem: the system has only one control unit, which will call multiple computing units. If a computing unit (as a service provider) is unavailable, the control unit (as a service caller) will be blocked and eve ...

Absrtact: This paper will first introduce the principle of java deserialization vulnerability, and then introduce how security tools detect and scan such vulnerabilities. This article is shared from Huawei cloud community< java deserialization vulnerability and its detection >, author: alpha1e0. 1 Introduction to Java deserialization ...

Phoenix installation and use 1. Background introduction 1.1 Phoenix definition Phoenix is an open source SQL skin for HBase. You can use the standard JDBC API instead of the HBase client API to create tables, insert data, and query HBase data. 1.2 Phoenix features Easy integration: such as Spark, Hive, Pig, Flume and Map Reduce. Good per ...