Big data - MySQL system information function

1. Function to obtain MySQL version number, number of connections and database name (1)version() version() returns a string indicating the MySQL server version, which uses the utf8 character set. [example] check the current MySQL version number. The SQL statement is as follows: mysql> select version(); +-----------+ | version() | +-------- ...

Posted by galvin on Sat, 21 May 2022 07:51:54 +0300

SVD and CUR self summary

SVD and CUR self summary reference resources: https://www.cnblogs.com/endlesscoding/p/10033527.html https://blog.csdn.net/WangWeb1998/article/details/114376298 1. SVD (singular value decomposition) definition: There is one m × n ...

Posted by shruti on Sat, 21 May 2022 02:38:13 +0300

Improve Spring Boot REST API error handling

introduction Spring Boot provides an excellent exception handling mechanism. The default implementation of ErrorController is good at catching and handling exceptions. In addition, you can also implement @ExceptionHandler yourself to catch and handle specific exceptions. However, there is room for improvement here: Even if a custom @Exceptio ...

Posted by MattWeet on Fri, 20 May 2022 18:31:37 +0300

Viewing successfully submitted offset indicator in Flink WebUI is negative

1. Problems After submitting a flink task, I went to WebUi to check the offset indicator, and found that the value turned out to be a negative number (as shown below): The definition given on the official website of this indicator is: For each partition, the offset of the last successful submission to Kafka; so this value is not normal anyway. ...

Posted by jefrat72 on Wed, 18 May 2022 15:44:05 +0300

SOA distributed software architecture combined with Domain Driven Design

1, Definition of SOA and DDD SOA and DDD are common system architectures, but the core of them is different. SOA (service-Oriented Architecture) was proposed by Gartner in 1996. It is a distributed software architecture. It can deploy, combine and use loosely coupled coarse-grained application components through the network according to requi ...

Posted by marcela1637 on Wed, 18 May 2022 13:32:18 +0300

Debezium specifies binlog location to initialize exception troubleshooting and repair

Abnormal phenomenon Recently, the project needs to use Debezium to specify the binlog location to read data. When FileDatabaseHistory is configured to save offset, an unrecognized schema exception will appear. 14:52:18.237 [blc-9.135.12.10:3307] ERROR io.debezium.connector.mysql.MySqlStreamingChangeEventSource - Encountered change event ' ...

Posted by jasonscherer on Wed, 18 May 2022 01:40:00 +0300

How to get Docker images to take off, so simple to set up

I. Introduction Docker is great to use, especially when it comes to DevOps practices. However, when you pull mirrors in China or locally, you often encounter various "constipation" - either the mirror pull is slow, or the connection is intermittent, or the connection times out! When our images are large (like someone dropped a Warcr ...

Posted by genom on Tue, 17 May 2022 13:01:00 +0300

02. Implementation principle and source code analysis of Flink Client

Personal official account: Implementation principle of Flink Client Before we interpret the source code of Flink Client, we must first understand its implementation principle. Main functions of Flink Client We can see that the FLink Client mainly has three tasks. The first is to run the Application, the second is to operate and ma ...

Posted by statrat on Tue, 17 May 2022 00:17:30 +0300

Financial Computing and Programming matplotlib Preliminary

Here is the second lesson in Financial Computing and Programming What I'm learning today is matplotlib - the most basic drawing library in python. import matplotlib.pyplot as plt import numpy as np 1. We first generate a one-dimensional y (to draw a line chart) Just draw a picture np.random.seed(250) y = np.random.standard_normal(20) x ...

Posted by gfmitchell on Mon, 16 May 2022 09:22:37 +0300

Go launched http2 0 request flow analysis (later) - header compression

Reading suggestions This is HTTP 2 0 series, the author recommends reading in the following order: HTTP request in Go -- http1 1 request process analysis Go launched http2 0 request process analysis (previous) Go launched http2 0 request flow analysis (Part 2) -- data frame & flow control review In the previous article (* http2clientco ...

Posted by brandone on Mon, 16 May 2022 09:17:40 +0300