Question: How to list tables inside tablespaces in a MuSQL cluster? The following query meets the aim of the question, lists the database, table name and the corresponding tablespace: SELECT DISTINCT t.table_schema, t.table_name, p.tablespace_name FROM partitions p JOIN TABLES t ON (t.table_schema=p.table_schema and t.table_name = p.table_name) WHERE t.engine='ndbcluster' and tablespace_name IS NOT NULL … [Read more...] about How to List Tables Per Tablespace In MySQL Cluster
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How To Create a Local Yum Repository for MySQL Enterprise Packages
1. Obtaining the yum repo tarball 1. Log on to support.oracle.com using your Oracle SSO ID. 2. Click on the "Patches & Updates" tab. 3. Click the "Product or Family (Advanced)" button to search by product. 4. Type "MySQL Server" for the Product. 5. Select the desired version in the "Release" pulldown. 6. Select "Linux x86-64" in the "Platform" pulldown. 7. Select "Description" in the first "and" pulldown under "Platform". 8. Select "contains" in the search type … [Read more...] about How To Create a Local Yum Repository for MySQL Enterprise Packages
MySQL Server Error – “Can’t Create A New Thread (errno 11)”
OS error 11 is "Resource temporarily unavailable". The most common cause of receiving this error when trying to create a new thread is having hit the process's kernel enforced a limit on open file descriptors. The second most common cause is having hit the process's kernel enforced limit on the number of processes/threads. Here are the factors involved: The system-wide limits: sysctl -e fs.file-max && sysctl -e kernel.threads-max The per-process limits (in a *new* shell): ulimit -n, grep … [Read more...] about MySQL Server Error – “Can’t Create A New Thread (errno 11)”
How to use a Wrapper Script to set Custom Per-Process Attributes for MySQL Server
There may be times you need to set custom per-process limits or attributes. It is possible to patch mysqld_safe, but using a wrapper script is easier to implement. In earlier versions, you could use mysqld_safe's mysqld= option to specify the path to your wrapper script, but this feature was removed as of 5.5.52, 5.6.33 and 5.7.15. Currently the simplest solution is to rename the existing mysqld (e.g. to mysqld.bin), and put your script named mysqld in the same directory. Rename the … [Read more...] about How to use a Wrapper Script to set Custom Per-Process Attributes for MySQL Server
Backup and Restore Of Group Replication Node ( MySQL 8.0 )
Note: In MySQL Server 8.0.X you must use the exact same patch release of MEB as the Server, eg MySQL Server 8.0.13 requires the use of MEB 8.0.13. The Basics For *nix OSes, the document uses a shell expansion for simple naming of folders with "todays" date+time, eg shell:~ # d="$(date '+%d%b_%H%M')" shell:~ # echo $d 13Nov_1338 It is, of course, possible to adjust this as any existing naming conventions dictate. Simple high level backup / restore commands: creates an image backup ( … [Read more...] about Backup and Restore Of Group Replication Node ( MySQL 8.0 )
MySQL Server 8.0 – How to create a REPLICATION SLAVE using MEB
The Problem A replication slave cannot continue replicating from its Master. One such example is that after being stopped for a long ( or longer than anticipated ) timeframe, the BINARY LOGS required on the Master have been purged. [ERROR] [MY-013114] [Repl] Slave I/O for channel 'group_replication_recovery': Got fatal error 1236 from master when reading data from binary log: 'Cannot replicate because the master purged required binary logs. Replicate the missing transactions from elsewhere, or … [Read more...] about MySQL Server 8.0 – How to create a REPLICATION SLAVE using MEB
How to configure resource groups for MySQL Server running on Linux
The following provides the procedure for configuring and using resource groups under Linux: 1. To use cgroups, you must install the "libcgroup" package on your system: # yum install libcgroup 2. Create a config file for cgroups: # vi /etc/cgconfig.conf mount { cpu = /cgroup/cpumem; cpuset = /cgroup/cpumem; memory = /cgroup/cpumem; } # High priority group group mysqldb { cpu { # Allocate the relative share of CPU resources equal to 75% cpu.shares="750"; } cpuset { # No … [Read more...] about How to configure resource groups for MySQL Server running on Linux
How To Configure Separate Override.conf For Multiple MySQL Instances Using Systemd
If the system services are managed by systemd, the systemd daemon should be aware of the PID file location of process to start/stop/restart it. On a system with systemd support, "override.conf" is used to specify both "PIDFile" and "ExecStart" with PID file location. Any setting of the process ID file in MySQL option file (my.cnf) is ignored. This post covers the case when we need to create a separate "override.conf" files for multiple MySQL instances management on the same server. In the … [Read more...] about How To Configure Separate Override.conf For Multiple MySQL Instances Using Systemd
Managing MySQL Using Systemd As A Non Root User
To facilitate a non root user, e.g. the mysql OS user, to stop and start MySQL Server using OS level system administration tools which rely on Systemd. The following entry in the sudoers file will allow the OS user mysql to stop and start the mysql server via the OS administration wrapper. # visudo ## MySQL Admin Cmnd_Alias MYSQLADMIN = /usr/bin/systemctl stop mysqld, /usr/bin/systemctl start mysqld,/usr/bin/systemctl restart mysqld mysql ALL=MYSQLADMIN As the mysql OS user , the Service … [Read more...] about Managing MySQL Using Systemd As A Non Root User
How to find Which Process Is Killing mysqld With SIGKILL or SIGTERM on Linux
To determine which process is sending the signal to mysqld, it is necessary to trace the signals through the Linux kernel. Two options to do this are: the audit log (auditd) systemtap Each of these methods will be discussed in the following sections. Audit Log The audit log is simple to set up, but does not provide fine grained control of which processes and signals are monitored; everything is included. So the log can become quite noisy, so it is recommended to disable the … [Read more...] about How to find Which Process Is Killing mysqld With SIGKILL or SIGTERM on Linux