setup_instruments 与Setup_consumers介绍
setup_instrumentsInstruments 是不同组件集的组合,例如wait、io、sql、binlog、file等。如果我们将这些组件组合起来,它们将成为帮助我们解决不同问题的有意义的工具。例如,wait/io/file/sql/binlog是提供有关二进制日志文件的等待和 I/O 详细信息的工具之一。Instruments从左侧读取,然后组件将添加分隔符“/”。我们添加到Inst
mysql主从库执行计划不同
SQL:SELECT COUNT(l.`id_xx_cluster`) FROM app_xx_xx l where 1=1 AND l.id_xx_cluster IN (SELECT a.applicationName FROM axxxx_info a WHERE a.`axxxxStatus`!='02' GROUP BY a.applicationName);主库执行计划
聊一聊MySQL的直方图
前一段时间和一个客户在优化SQL,发现其实收集了直方图以后看起来对执行计划起不到多大影响。MySQL 8.0后开始支持直方图,我们可以通过analyze table时进行收集,ANALYZE TABLE t UPDATE HISTOGRAM ON c1, c2, c3 WITH 10 BUCKETS;ANALYZE TABLE t UPDATE HISTOGRAM ON c1, c3 WITH 1
利用HeatWave + MySQL实现高性能海量数据分析
原文:https://mp.weixin.qq.com/s/uCjkZTlBG647xHHOPfFddQ HeatWave云服务是Oracle新推出的与MySQL集成的、高性能的基于内存的查询加速器,普通用户可将分析和统计查询的性能提高几个数量级。HeatWave集群支持扩展到数千个内核,比Amazon Aurora快1100倍,比Amazon Redshift快2.7倍,而成本仅为其三分之一。带
MySQL null和''分析
INNODB:CREATE TABLE `test2` ( `col1` VARCHAR( 10 ) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL , `col2` VARCHAR( 10 ) CHARACTER SET utf8 COLLATE utf8_ge
Mysql operator for Kubernetes介绍
MySQL Operator for Kubernetes是一个用于安装和管理一个或多个MySQL InnoDB Clusters 的操作工具。MySQL operator本身在Kubernetes集群中运行,并由Kubernetes Deployment控制,以确保 MySQL operator保持可用和运行。MySQL Operato
pprof 分析mysqld 内存调用(笔记)
---- Install TCMALLOC 1.unpack tar zxvf gperftools-2.9.1.tar.gz ./configure --enable-frame-pointers --prefix=/u
mysql 5.7 vs 8.0默认值变化(笔记)
Changed Server DefaultsOption/ParameterOld DefaultNew DefaultServer changescharacter_set_serverlatin1utf8mb4collation_serverlatin1_swedish_ciutf8mb4_0900_ai_ciexplicit_defaults_for_timestampOFFONoptim
[ERROR] [MY-012872] [InnoDB] [FATAL] Semaphore wait has lasted > 600 seconds
InnoDB: ###### Diagnostic info printed to the standard error stream2021-11-19T14:52:21.671328+08:00 0 [ERROR] [MY-012872] [InnoDB] [FATAL] Semaphore wait has lasted > 600 seconds. We intentionally
[InnoDB] Assertion failure: ut0ut.cc:553 thread 140235111884544【笔记】
APPLIES TO:MySQL Server - Version 8.0 and laterInformation in this document applies to any platform.SYMPTOMSOn : 8.0 version, Server Crash ERROR----------------------- [InnoDB] Assertion fai
MYSQL The Server Shutdown Process(笔记)
The server shutdown process takes place as follows:The shutdown process is initiated.This can occur initiated several ways. For example, a user with the SHUTDOWN privilege can execute a 
MYSQL 8.0 Upgrade &Downgrade的几点注意
ImportantDowngrade from MySQL 8.0 to MySQL 5.7, or from a MySQL 8.0 release to a previous MySQL 8.0 release, is not supported. The only supported alternative is to restore a backup taken before upgrad
Innodb内存管理解析[转载]
本文转自http://mysql.taobao.org/monthly/2021/01/06/本文主要介绍innodb的内存管理,涉及基础的内存分配结构、算法以及buffer pool的实现细节,提及change buffer、自适应hash index和log buffer的基本概念和内存基本配比,侧重点在内存的分配和管理方式。本文所述内容基于mysql8.0版本。基础内存分配在5.6以前的版本
MySQL数据库架构——高可用演进
原创 徐轶韬 MySQL解决方案工程师 MySQL发展至今,在高可用性方面
MySQL数据库SYS CPU高的可能性分析
转自:http://mysql.taobao.org/monthly/2015/05/02/问题背景我们在管理繁忙的 MySQL 数据库时,可能都有碰到 SYS CPU 高的经历:系统突然 SYS CPU 高起来,甚至比 USER CPU 高很多,这时系统 QPS、TPS 急剧下降。SYS CPU高是什么造成的呢?主要有2种可能:context switch 不高,但在内核态 spin,导致 SY
MYSQL connector 的 NullReferenceException bug
mysql connector 连接报错, 客户端在MySqlClient.MySqlDataReader.NextResult() 处报错,IIS进程池crash后 db端提示Got an error reading communication packets。异常时堆栈调用信息:ServerConnectionInfo.Finallize()=>ServerConnection
MYSQL connector/.NET 默认的 show variables 引起的线程mutex锁争用
1)检查当时的主机资源状态,其cpu 内存,磁盘IO 负载实际都并不高。 复查主机资源发现当时的load avage指标异常,1分钟平均负载量达到100以上,5分钟平均负载量达到90以上,10分钟平均负载量达到60以上,说明当时cpu的运行队列出现排队现象。2)当时的thread cache size 分别出现两次耗尽情况,大量的线程处于running的状态。3)从后台慢日志看,show vari
关于mysql字符集及排序规则设置
How Can I Change the Default Character Set and Collation for a Database in MySQL? (Doc ID 1023320.1)To determine the default character set and collation for a database, enter this SQL statement:查询:Beg
MYSQL CPU部分单核占满会影响建立数据库连接效率?
问题描述:cpu 瞬间爆满,前台应用程序报出 too many connection错误,mysql ERROR日志报出[Warning] Too many connections,操作系统日志报出: kernel: TCP: time wait bucket table overflow。主机的资源情况如下:1.CPU 总体资源不高,但出现单核使用率100% 情况2.CPU 系统中断和上下文切换
MYSQL count标量子查询改left join
SELECT homepageId, userId, homepagesummary, totalviews, totalleadpercents, totalappointments, homepagestatus, linkphone, imagepath, createtime, updatetime, recommendtime, sortcode, designerimagepath,