AWS / Azure / GCP Cloud | Database | Data Analytics | LakeHouse | Machine Learning | Shrenik Parekh

Install DC/OS CLI (1.11) on Linux: Execute following command on Linux machine to connect with DC/OS cluster [ -d /usr/local/bin ] || sudo mkdir -p /usr/local/bin && curl https://downloads.dcos.io/binaries/cli/linux/x86-64/dcos-1.1 1 /dcos -o dcos && sudo mv dcos /usr/local/bin && sudo chmod +x /usr/local/bin/dcos && dcos cluster setup https://<cluster_name>.com --insecure && dcos It will make directory /usr/local/bin if it doesn't exist, curl (copy url) command will download dcos (download dcos) into the directory dcos, -o stands for output to the directory dcos move dcos directory to /usr/local/bin change mode of /usr/local/bin/dcos to executable execute command for dcos utility using command dcos cluster setup    Execute command for dcos: #dcos Usage:   dcos [command] Commands:   auth       Authenticate to DC/OS cluster   cluster       Manage your DC/OS clusters   config       Manage the DC/OS configuration file   help     

Install DC/OS CLI on WINDOWS: 01. Download the DC/OS CLI executable from https://downloads.dcos.io/binaries/cli/windows/x86-64/dcos-1.11/dcos.exe 02. Change directory to location where DC/OS CLI executable is saved. 03. Configure connection DC/OS cluster using following command. C:\DCOS> dcos cluster setup https://<cluster_name.com> 04. Type dcos on command prompt C:\DCOS> dcos Usage:   dcos [command] Commands:   auth       Authenticate to DC/OS cluster   backup       Access DC/OS backup functionality   cluster       Manage your DC/OS clusters   config       Manage the DC/OS configuration file   help       Help about any command   job       Deploy and manage jobs in DC/OS   license       Manage your DC/OS licenses   marathon       Deploy and manage applications to DC/OS   node       View DC/OS node information   package       Install and manage DC/OS software packages   plugin       Manage CLI plugins   security       DC/OS security related commands   service       Manag

MySQL 8.0.20 InnoDB enhancement: Improvement for CATS: CATS - Contention Aware Transaction Scheduling is improved in MySQL 8.0.20. For CATS transaction weight computation is required. From MySQL 8.0.20 this CATS weight computation is performed on separate thread entirely, which improves performance computation performance and accuracy. FIFO (First in first out) is removed from MySQL 8.0.20. Transaction scheduling performed by the CATS algorithm since MySQL 8.0.20, which used be performed by FIFO. Explore more: https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-20.html https://mysqlserverteam.com/contention-aware-transaction-scheduling-arriving-in-innodb-to-boost-performance/ Storage area for Doublewritter: Doublewritter buffer used to store data in system tablespace, now it is has its own storage area in doublewriter files, which has resulted in flexibility to place double writer buffer pages, increase throughput, reduce write latency. System variable for doublewritter storage

MySQL slave Error_code: 1032 | MySQL slave drift: With several MySQL, instance with master slave replication, I have one analytics MySQL, environment which is larger in terabytes, compared to other MySQL instances in the environment. Other MySQL instances with terabytes of data are running fine master, slave replication. But this analytics environment get started generating slave Error_code :1032. mysql> show slave status; Near relay log: Error_code: 1032; Can't find record in '<table_name>', Error_code: 1032; handler error HA_ERR_KEY_NOT_FOUND; the event's master log <name>-bin.000047, end_log_pos 5255306 Near master section: Could not execute Update_rows event on table <db_name>.<table_name>; Can't find record in '<table_name>', Error_code: 1032; Can't find record in '<table_name>', Error_code: 1032; handler error HA_ERR_KEY_NOT_FOUND; the event's master log <name>-bin.000047, end_l

 Master Slave Replication: After configuring master slave replication when you check slave status on slave you got Fatal error: The slave I/O thread stops because master and slave have equal MySQL server UUIDs; these UUIDs must be different for replication to work. Cause: Because you might have copied data directory from master to slave, and same auto.cnf file exists on master and slave.  Solution: Stop mysql daemon on slave, remove auto.cnf file from data directory on slave , start slave, and check slave status. You will be fine.  Stop MySQL daemon on slave: #systemctl stop mysqld Delete auto.cnf file from the data directory: # rm -rf auto.cnf Start MySQL daemon: #systemctl start mysqld