This Log Buffer edition has collected some of the valuable blog posts from different databases like Oracle, SQL Server and MySQL.
Oracle:
A few years back Deva wrote about how to use tcpdump on very busy hosts. That post sparked my interest about exploring how to measure the impact of tcpdump on very busy hosts. In this post, I wanted to highlight how much of an impact there really is and what options you have to make the query collection much more effective.
Some things you need to know:
This Log Buffer travels wide and deep to scour through the Internet to bring some of the most valuable and value-adding blog posts from Oracle, SQL Server and MySQL.
Oracle:
What is SQLcl ? SQLcl is a new command line interface like SQL*PLUS coming along with SQL Developper 4.1 Early Adopter. It’s a lightweight tool (only 11MB) developed by the SQL Developer team, which is fully compatible with Windows and Unix/Linux. Also, you don’t need to install it so it’s totally portable.
Find Users with DBA Roles.
Virtual Compute Appliance 2.0.2 Released.
In case you are not …
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1) To find slow queries
pt-query-digest /var/lib/mysql/cloud-server-01-slow.log > slowqueroutput.log
2) Between a particular time range
pt-query-digest –since ’2015-04-10 00:00:00′ –until ’2015-04-10 23:59:59′ /var/lib/mysql/cloud-server-01-slow.log > slowqueryrange.log
3) For a particular database
pt-query-digest –filter ‘$event->{db} && $event->{db} =~ /employee/’ /var/lib/mysql/cloud-server-01-slow.log > slowqueroutputemp.log
pt-query-digest –filter ‘$event->{db} && $event->{db} =~ /market/’ /var/lib/mysql/cloud-server-01-slow.log > slowqueroutputmkt.log
4) For a particular user
pt-query-digest –filter ‘$event->{user} && $event->{user} =~ /root/’ /var/lib/mysql/cloud-server-01-slow.log > slowqueryoutputuser.log …
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Recently i encounter an uprising among PHP Developers that , they
must write a script additionally checking the strength of MySQL
user password at creation time.
So, just for note that there is ready to use plugin in MySQL
named: validate_password.so
The file location is default in plugin_dir in Linux:
mysql> select @@plugin_dir; +--------------------------+ | @@plugin_dir | +--------------------------+ | /usr/lib64/mysql/plugin/ | +--------------------------+ 1 row in set (0,00 sec)
List this directory:
[root@linuxsrv3 plugin]# ls adt_null.so auth_test_plugin.so innodb_engine.so mypluglib.so qa_auth_server.so validate_password.so auth.so daemon_example.ini libdaemon_example.so qa_auth_client.so semisync_master.so auth_socket.so debug libmemcached.so qa_auth_interface.so semisync_slave.so
As you see there is a …
[Read more]On Tuesday Steaphan Greene announced that all currently-pushed changes have now been rebased onto the newly-released upstream MySQL-5.6.24.
The new branch at this point is available on github.
Our .deb and .rpm builds are available in the PSCE repo as well as being browsable here http://repo.psce.com/download/webscalesql/
Instructions for using the repo are available for Debian …
[Read more]Galera Cluster For System Administrators, DBAs And DevOps
Galera Cluster for MySQL, MariaDB and Percona XtraDB involves more effort and resource to administer than standalone systems. If you would like to learn how to best deploy, monitor, manage and scale your database cluster(s), then this new online training course is for you!
The course is designed for system administrators & database administrators looking to gain more in depth expertise in the automation and management of Galera Clusters.
What: A one-day, instructor-led, Galera Cluster management training course
When: The …
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Complimenting the expanded CREATE USER syntax introduced in
MySQL Server 5.7.6 is more useful ALTER USER
syntax. Before MySQL Server 5.7.6, ALTER USER
could only be used to expire a user’s password. That’s pretty
limited. With changes made in MySQL Server 5.7.6, a better
distinction is made between privilege-level attributes (those
which are managed via GRANT and REVOKE
statements) and account-level attributes (those managed using
CREATE USER and ALTER USER
statements). MySQL has a long history of confusing these –
for example, requiring a GRANT …
I use a Fedora 20 VM image to teach Oracle and MySQL technology. Last week, I expanded the Fedora VM image to support a full LAMP stack. This blog shows you how to install Ruby on Fedora and successfully generate the Rails gems.
Connect as the root user and use yum to install the
libraries. My approach is by library or small groups. Naturally,
you start with the ruby library.
yum install ruby |
You will see the following:
Loaded plugins: langpacks, refresh-packagekit mysql-connectors-community | 2.5 kB 00:00 mysql-tools-community | 2.5 kB 00:00 mysql56-community | 2.5 kB 00:00 pgdg93 | 3.6 kB 00:00 updates/20/x86_64/metalink … |
This topic is not for all situations but in my situation it
helps.
The problem is with Slave is lagging behind master in very large
numbers and the relay logs are continously growing.
Slave is using:
Relay_Log_File: mysql-relay-bin.000031
But in folder where relay log resides, was created up to:
mysql-relay-bin.000135
And it is continously growing.
So what i decide to do, again step-by-step i edited my.cnf file
as follows:
1. I have 13 database so give to slave paralel workers
13:
slave-parallel-workers = 13
2. Disabled sync_binlog:
sync_binlog = 0
3. Changed at_trx_commit from 1 to 0:
innodb_flush_log_at_trx_commit = 0
4. Gave log_at_timeout (only from 5.6.6>) to 10:
innodb_flush_log_at_timeout = 10
5. Disabled slow query log( or commented out)
So …
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