• Are you hungry? Evolution of eMonitor


    Introduction:Observability, as one of the core links of technology system, follows the rapid development of EMM technology and makes continuous self innovation. preface Back in 2008, Zhang xuhao, Kang Jia and others, who were still studying in Shanghai Jiaotong University, founded “hungry Yao” in Shanghai. Starting from the campus takeout scene, hungry Yao has grown […]

  • Five questions, three strategies, hand in hand teach you to customize app performance monitoring scheme


    Introduction:To sum up, we can count the number of errors, error rate, number of affected users, proportion of affected users and other indicators of different types of errors in a certain time range. In the detailed classification of indicators, we can also define monitoring with different dimensions, such as version number. Author: Youmeng + u-apm […]

  • Prometheus monitoring Oracle Database


    background This article briefly introduces how Prometheus monitors Oracle database through exporters, and what indicators should be paid attention to. oracledb_exporter oracledb_ Exporter is an application that connects to Oracle database and generates Prometheus metrics, set up Show how to install and set up Oracle dB_ To monitor the Oracle database using Prometheus. oracledb_ The […]

  • Some gossip from Prometheus


    Who is Prometheus? From Wikipedia: in Greek mythology, it is one of the gods of the Titans, whose name means “foresight”. Prometheus and Athena, the goddess of wisdom, jointly created human beings. Prometheus was responsible for sculpting human shapes with clay, while Athena poured soul into clay figurines and taught human beings a lot of […]

  • Common types conversion of golang


    ** 1.Type(expression): ** int( time.Now (). Weekday()) // week to int int( time.Now (). Month ()) // month to int var a float64 a = 3.1 B: = int (a) // float64 to int var a int a = 1 B: = Int64 (a) // int to Int64 ** 2. Strconv package: ** String and […]

  • The method of querying the last rebuild time of SQL Server index


    A friend has a job whose execution of rebuild index has stopped. He asked me if I could check which indexes have been rebuilt. I thought Sys.index perhaps Sys.objects Similar information will be stored and not found.  Check from the Internet, SQL server does not store similar information. But because rebuild index will update statistics […]

  • SQL statement to query index usage


    SELECT sch.name + ‘.’ + t.name AS [Table Name], i.name AS[Index Name], i.type_desc, ISNULL(user_updates,0) AS [Total Writes], ISNULL(user_seeks +user_scans + user_lookups,0) AS [Total Reads], s.last_user_seek, s.last_user_scan , s.last_user_lookup, ISNULL(user_updates,0) – ISNULL((user_seeks+ user_scans +user_lookups),0)AS [Difference], p.reserved_page_count * 8.0 / 1024 as SpaceInMB FROM sys.indexes AS i WITH (NOLOCK) LEFT OUTERJOIN sys.dm_db_index_usage_statsAS s WITH (NOLOCK) ON s.object_id […]

  • SQL statement to realize query and create missing index automatically


    SELECT migs.avg_total_user_cost*(migs.avg_user_impact/ 100.0) *(migs.user_seeks + migs.user_scans) ASimprovement_measure, ‘CREATE INDEX[missing_index_’ + CONVERT(varchar, mig.index_group_handle) + ‘_’ + CONVERT(varchar, mid.index_handle) + ‘_’ + LEFT(PARSENAME(mid.statement, 1), 32) + ‘]’ + ‘ ON ‘ + mid.statement + ‘ (‘ + ISNULL(mid.equality_columns,”) + CASE WHEN mid.equality_columns IS NOT NULL AND mid.inequality_columnsIS NOT NULL THEN ‘,’ ELSE ” END + ISNULL(mid.inequality_columns, ”) […]

  • [data structure] – polynomial multiplication


    Title Requirements The non-zero coefficients and corresponding exponents of two polynomials are input from the character file to establish the polynomial representationLinked Storage Structure To calculate the product of the two polynomials and to output the product of the polynomialsAll nonzero coefficients and corresponding exponentsTo another character file. Algorithm principle The multiplication of two polynomials […]

  • [hematemesis finishing] we strongly recommend open source practical projects worth learning on GitHub (in continuous update, it is recommended to collect ten thousand words long articles)


    We strongly recommend open source projects worth learning on GitHub, including web front end, Java, PHP, python, Android / IOS, big data, blockchain, AI machine learning, data structure and algorithm, design pattern, etc. Why do you want to write this article? A few days ago, I saw a new student in wechat group asking if […]

  • Oracle table space expansion


    1. Table space capacity index query SELECT TABLESPACE_ Name “table space,”, To_char(Round(BYTES / 1024, 2), ‘99990.00’) ||It’s true, To_char(Round(FREE / 1024, 2), ‘99990.00’) ||’g’ “existing,”, To_char(Round(( BYTES – FREE ) / 1024, 2), ‘99990.00’) ||’g’ “use”, To_char(Round(10000 * USED / BYTES) / 100, ‘99990.00’) ||’%’ “proportion” FROM (SELECT A.TABLESPACE_NAME TABLESPACE_NAME, Floor(A.BYTES / ( 1024 * […]

  • Observability of computing serverless | functions from zero


    Introduction:This paper is divided into three parts: the basic concepts of observability are introduced in the overview, including logging, metrics and tracing; then logging, metrics and tracing in function calculation are introduced in detail; finally, taking several common scenarios as examples, how to quickly locate and solve problems in function calculation is introduced. By Xia […]