In previous blogs we have shown how MySQL Cluster can use the
Read Backup
feature to improve performance when the MySQL Server and the NDB
data
node are colocated.
There are two scenarios in a cloud setup where additional
measures are
needed to ensure localized read accesses even when using the Read
Backup
feature.
The first scenario is when data nodes and MySQL Servers are not
colocated.
In this case by default we have no notion of closeness between
nodes in
the cluster.
The second case is when we have multiple node groups and using
colocated
data nodes and MySQL Server. In this case we have a notion of
closeness
to the data in the node group we are colocated with, but …
Sequences are used to requesting unique values on demand, The best use case of sequences is to have a unique ID. , that can be used across multiple tables. In some cases sequences are really helpful to have an identifier before an actual row is inserted. With the normal way of having an automatically incrementing identifier, the identifier value will only be available after insert of the row and the identifier will only be unique inside its own table. MariaDB Server 10.3 follows the standard and includes compatibility with the way Oracle does sequences introduced in Oracle Database Server on top of the standard.
Simple steps to create a sequence in MariaDB 10.3 onwards, a create statement is used:
MariaDB [MDB101]> CREATE SEQUENCE Seq1_100 -> START WITH 100 -> INCREMENT BY 1; Query OK, 0 rows affected (0.015 sec)
This creates a sequence that starts at 100 and is incremented with 1 every time a …
[Read more]ProxySQL 1.4.2 introduced native clustering, allowing several ProxySQL instances to communicate with and share configuration updates with each other. In this blog post, I’ll review this new feature and how we can start working with 3 nodes.
Before I continue, let’s review two common methods to installing ProxySQL.
ProxySQL as a centralized server
This is the most common installation, where ProxySQL is between application servers and the database. It is simple, but without any high availability. If ProxySQL goes down you lose all connectivity to the database.
ProxySQL on app instances
Another common setup is to install ProxySQL onto each application server. This is good because the loss of one ProxySQL/App server will not bring down the entire application.
For more information about the previous installation, please visit this link …
[Read more]We are all familiar with “.frm” files since the earliest days of MySQL, The community has been continuously requesting for replacement of file-system based metadata for several good reasons, So with MySQL 8.0 “.frm” files are gone for ever, Going forward MySQL stores table metadata in the data dictionary tables which uses InnoDB storage engine. This blog is about MySQL 8.0 data dictionary and how it creates value for MySQL going forward:
How file based metadata management used to work in the past (before MySQL 8.0) ?
- Every table in MySQL will have corresponding .frm file, This .frm file stores information like column names and data-types in the binary format, In addition to the .frm file, there are .trn, .trg and .par files to support triggers, trigger namespace and partitioning .
What are major bottlenecks faced due to the usage of file based metadata management …
[Read more]
A new week of blogs about our development in MySQL Cluster
7.6.
After working a long time on a set of new developments, there is
a lot
of things to describe. I will continue this week with discussing
sharding
and NDB, a new cloud feature in 7.6 and provide some
benchmark
results on restart performance in 7.6 compared to 7.5. I am also
planning
a comparative analysis for a few more versions of NDB.
In the blog serie I have presented recently we have
displayed
the performance impact of various new features in MySQL
Cluster
7.5 and 7.6. All these benchmarks were executed with tables
that
used 1 partition. The idea behind this is that to develop a
scalable application it is important to develop …
The MySQL error log is an essential part of database server performance monitoring. Whenever something goes wrong or performance degrades, the Error Logs are usually the first place we look to start troubleshooting.
The MySQL Error Log is one of three related log types:
- The Error Log: It contains information about errors that occur while the server is running (as well as server start and stop events).
- The General Query Log: This is a general record of what mysqld is doing (connect, disconnect, queries).
- The Slow Query Log: It consists of “slow” SQL statements as defined in the long_query_time global variable.
You can enable error log monitoring to allow Monyog to keep an eye on your MySQL Error Log, and notify you when something goes awry. Moreover, Monyog combines the General Query, Slow Query and Error logs in a single view for both network and cloud servers. For example, in the …
[Read more]Since summer 2017, Amazon RDS supports encryption at rest using AWS Key Management Service (KMS) for db.t2.small and db.t2.medium database instances, making the feature now available to virtually every instance class and type.
Unless you are running Previous Generation DB Instances or you can only afford to run a db.t2.micro, every other instance class now supports native encryption at rest using KMS. As for the Amazon documentation:
Encryption on smaller T2 database instances is useful for development and test use cases, where you want the environment to have identical security …
[Read more]MySQL 8.0 General Availability was announced in April and it comes with a host of new features. The overview about the new features and improvements made in MySQL 8.0 can be found in the following blog.
The server can be upgraded by performing either an INPLACE upgrade or LOGICAL upgrade. …
Join Percona Chief Evangelist Colin Charles as he covers happenings, gives pointers and provides musings on the open source database community.
Some big news out from Microsoft about their acquisition of GitHub for $7.5 billion. GitHub hosts many projects, including from the MySQL ecosystem, but maybe more interesting is that their DBA team is awesome, give great talks, and are generally prolific writers. Some of the cool tools the MySQL world has gotten thanks to the excellent team include (but are not limited to): ccql, gh-ost for triggerless online schema migrations, and Orchestrator which is a GUI-based High Availability and …
[Read more]We will show you how to list all databases in MySQL, i.e how to have a list of all MySQL ...
The post How To Show A List Of All DataBases In MySQL appeared first on RoseHosting.