The Complete MariaDB Server tutorial

The Complete MariaDB Server Tutorial
Colin Charles, Chief Evangelist, Percona Inc.

colin.charles@percona.com / byte@bytebot.net

http://www.bytebot.net/blog/ | @bytebot on Twitter

Percona Live Europe Amsterdam, Netherlands

3 October 2016

License
• Creative Commons BY-NC-SA 3.0
2

whoami
• Chief Evangelist (in the CTO ofﬁce), Percona Inc
• Founding team of MariaDB Server (2009-2016),
previously at Monty Program Ab, merged with
SkySQL Ab, now MariaDB Corporation
• Formerly MySQL AB (exit: Sun Microsystems)
• Past lives include Fedora Project (FESCO),
OpenOfﬁce.org
• MySQL Community Contributor of theYear Award
winner 2014
3

MariaDB is very social
• facebook: fb.com/MariaDB.dbms
• twitter: @MariaDB
• g+: plus.google.com/+mariadb/
• Tweet things you learn with #mariadb
4

Agenda
• This talk is about MariaDB Server from the
MariaDB Foundation
• There is no focus on MariaDB MaxScale or
MariaDB ColumnStore from the MariaDB
Corporation
5

Who are you?
• Database Administrator (DBA)
• Developer
• Database Architect (DA)
7

Database Experience
• MySQL
• 4.1 or earlier?
• 5.0
• 5.1
• 5.5
• 5.6
• MariaDB
• 5.1
• 5.2
• 5.3
• 5.5
• 10.0
8

Understanding releases
• Alpha
• Beta
• Release Candidate
• Stable (GA)
• Labs
• Developer Milestone Releases (DMR)
9

What is MariaDB?
10
• Community developed
• Feature enhanced
• MariaDB doesn’t depend on MySQL for development -
many features are developed independently of MySQL
• Backwards compatible with MySQL
• (kind of) feature complete
• replication supported for easy migration

Aims of MariaDB
• Compatible, drop-in replacement to MySQL
• your application shouldn’t care that its
running MariaDB, easy upgrade (uninstall
mysql, install mariadb, continue ops!)
• Stable (bug-free) releases with no
regressions
• GPLv2
11

6 years, many server
releases
• MariaDB 5.1, GA February 2010
• MariaDB 5.2, GA November 2010
• MariaDB 5.3, GA February 2012
• MariaDB 5.5, GA April 2012
• MariaDB Galera Cluster, GA March 2013
• MariaDB 10.0.10 (March 2014)
• MariaDB 10.1.8 (October 2015)
12

MariaDB 5.6?
• There will never be a MariaDB 5.6 - the
numbers have changed
• Many companies will still continue to
support both MySQL and MariaDB releases
14

Importance of understanding
MariaDB (and MySQL)
• Generics are inefﬁcient
• Since you have chosen MariaDB:
• maximise its strengths
• minimise its weaknesses
17

Sample databases to
play with
• http://dev.mysql.com/doc/index-other.html
• sakila sample database, world
database (used in MySQL training),
menagerie database (used in book:
Beginning MySQL), employees
database (large dataset, comes with data -
best to play with)
18

Picking hardware
• Just use 64-bit hardware
• VM’s are improving to use 64-bit OSes &
software
• Physical > virtual
• Disk: battery backed storage, plan for RAID
usage
• MariaDB 10.1 has optimisations for ﬂash/SSD/
FusionIO
19

Testing MySQL
• Use MySQL Sandbox
• http://mysqlsandbox.net/
• Express one-click MySQL installs
• make_sandbox foo.tar.gz
• Does not require root privileges
20

Installation
• Binaries (tarballs) are available at http://mariadb.org/ (source too)
• Built, tested by MariaDB
• Graphical installer & conﬁguration for Microsoft Windows, with
HeidiSQL GUI
• Up-to-date predictable release schedule
• RPM, DEB packages are provided, includingYUM & APT
repositories
• Use the repository conﬁguration tool
• Inside Linux/*BSD distributions
• Easy to install, basic defaults, may be older than upstream
21

Upgrades
• Review changelogs carefully, even for minor
versions
• Make backups (using xtrabackup)
• Don’t forget to run mysql_upgrade
• by default with a distribution package
• Replication can reduce downtime by upgrading
the slave, promoting it, then upgrading the master
22

Upgrading from MySQL
5.0
• MariaDB 5.1 ﬁxes upgrades better than MySQL 5.1
handles this
• InnoDB + Archive tables upgraded properly
• mysql_upgrade, mysqlcheck have more options to see
what’s going on
• mysqlcheck wrong warnings removed
• MySQL 5.1 -> MariaDB 5.1 is “drop-in”
• https://mariadb.com/kb/en/upgrading-to-mariadb-from-
mysql/
23

Packages (RPM
example)
• MariaDB-common
• character sets
• MariaDB-shared
• latest libmysqlclient, some plugins,
/etc/my.cnf.d/
• MariaDB-compat
• compatible client libraries that
replace mysql-libs
• MariaDB-server
• The actual server!
• MariaDB-client
• mysql client utilities
• MariaDB-test
• test suite
• MariaDB-devel
• development headers enabling
you to build your own package
• MariaDB-CassandraSE
• plugin for CassandraSE
24

What is libmysqlclient?
• Client libraries
• Many applications are compiled against
libmysqlclient
• It is an Application Binary Interface (ABI)
• When you write in Java & use Connector/J,
Connector/J is compiled against libmysqlclient
• Similarly with PHP & Connector/PHP
25

MySQL utilities
• Why does MariaDB use all the same client utilities?
• Because the aim is to be a compatible drop-in
replacement
• There are very few non-MySQL utilities shipped:
aria_chk, aria_dump_log, aria_ftdump,
aria_pack, aria_read_log
• xtstat (PBXT) is deprecated in MariaDB 5.5
onwards
• mytop as it adds features not-present upstream
26

Finding help
• How do you know what CLI options to use?
• Use the man(ual) pages!
•man mysql
• man <command_name> usually works for
any CLI command
• HELP SELECT in mysql works too (help
tables) - HELP <operator>
27

Error messages
• perror is a great tool
• MariaDB-speciﬁc errors are 1900 and
above
• https://mariadb.com/kb/en/mariadb-error-
codes/#mariadb-speciﬁc-error-codes
28

mysql_secure_insta
llation
• Now that you’ve tested MySQL works ﬁne (by
default, no root password), it’s time to ensure you
secure the installation
• Set root password
• Remove anonymous users
• Disallow remote root login
• Remove test database
• Reload privileges
29

mysqladmin
• Manage user accounts, passwords,
permissions
• Display mysqld settings & status counters
• Shutdown, create, drop databases
shell> mysqladmin processlist
shell> mysqladmin extended-status
shell> mysqladmin -uroot -p create wordpress
30
SHOW PROCESSLIST
SHOW STATUS

mysqldump
• Dump schema and/or data to .sql ﬁle, tab
• Useful for backups, transferring data
• Locks for consistency, so troublesome
shell> mysqldump --all-databases > backup.sql
shell> mysqldump --all-databases --single-transaction >
backup.sql
31

Other tools
• There are many other command line
tools...
• Front-ends
• HeidiSQL
• Webyog’s SQLyog
• Sequel Pro (OSX)
32

Making client
connections
• TCP/IP is available on all platforms
• disable using --skip-networking
• Socket ﬁles available on Unix
• fastest communication path
• MySQL connections are generally cheap
• If you have many short running queries (typical web
app), you beneﬁt from MariaDB threadpool
• Set connection limit max_connections=n in my.cnf
34

Connection Pool
• mysqld’s main thread listens for connections
• Each connection has a thread assigned to it
• Threads can be:
• created newly
• reused from thread cache
• User authentication processed based on hostname,
username & password
• Client speciﬁc buffers for session variables are allocated
35

Query Cache
• Stores SELECT queries and their result sets
• Subquery cache exists only in MariaDB
• Frequently changed table data will cause
queries to naturally be missed
• Regularly replaced these days with
memcached, et al.
37

SQL Parser
• Lexical scanner & grammar rules
• Parse SQL into tokens
• Apply grammar rules to check statement
validity
• Construct a parse tree for Optimizer to
use
38

Optimizer
• Reads the parse tree and calculates the best query
execution plan (QEP) to handle query
• ﬁnd indexes
• determine JOIN order
• eliminate unnecessary tables
• etc.
• The optimizer is smart, don’t try to force query
plans
39

Pluggable Storage
Engines
• MariaDB can use many storage engines
with different features
• Installed/removed on ﬂy with INSTALL/
UNINSTALL PLUGIN
• Mixing & matching on same server, even on
same query
40

Value proposition
• Unmatched ﬂexibility + customisation potential
• MEMORY engine for performance/routine
lookup data
• Right storage engine can improve performance
in many applications
• ARCHIVE compresses data, up to 80%
• Partners & community beneﬁt from this
41

What makes engines
different?
• Storage: how the data is stored on disk
• Or in NDB (memory+disk), CassandraSE (access a Cassandra Cluster), SphinxSE
(access the Sphinx daemon)
• Indexes: improves search operations
• Memory usage: improves data access for speed
• Transactions: protects the integrity of your data (Atomic-Consistent-Isolated-
Durable - ACID)
• Locking level: MyISAM (table locks), InnoDB (row locks), old BDB (page locks)
• Data types: Data types may be converted, MEMORY doesn’t support TEXT, etc.
• Caching: InnoDB caches data & indexes, MyISAM caches indexes only (relying on OS
disk cache for data)
• Full-text search capability: MyISAM has this, InnoDB 5.6 got this
• GIS: MyISAM & Aria work (R-tree indexes exist), InnoDB 5.7 has this too
42

INFORMATION_SCHE
MA
• Holds metadata (data about the data) on all
other databases & tables, exposed as
regular tables
• Generated on the ﬂy
• Has extensions in MariaDB as we expose
more data than native MySQL
43

PERFORMANCE_SCH
EMA
• Allows for monitoring execution at a low
level
• This is a storage engine, monitoring server
events (anything that takes time & can be
instrumented)
• Tables are views or temporary tables that
use no on-disk storage
44

Transactional vs. non-
transactional
• Transaction-safe tables
(InnoDB) have advantages
over non-transaction safe
tables (MyISAM):
• server crash? Automatic
recovery, or a backup
+transaction log
• ROLLBACK can be
executed to ignore
changes
• Update fails? Changes
reverted
• Concurrency - tables w/
many update +
concurrent reads
• Disadvantages in today’s
environments (transaction
overhead = slower), more
disk space requirements,
more memory to perform
updates don’t seem like they
apply any longer
45

Indexes
• Tree Indexes
• B-Trees
• B+Trees (InnoDB)
• T-Trees (NDB)
• Red-black binary trees
(MEMORY)
• R-Trees (MyISAM for spatial
indexes)
• Hash Indexes (MEMORY, NDB,
InnoDB)
• If table ﬁts entirely in
memory, fastest way to
perform queries is a hash
index
• InnoDB has an internal
adaptive hash index. InnoDB
monitors index searches,
and if it notices that it will
beneﬁt from a hash index,
InnoDB automatically builds
one. (5.1.24 and greater)
46

MyISAM
• Pros?
• excellent INSERT
performance
• small footprint
• supports full-text
search (FTS)
• Cons?
• no transactions
• no foreign key
support
• Typical uses
• logging
• auditing
• data warehousing
47

MyISAM II
• In my.cnf, remember to
set the key_buffer_size.
This is memory*0.40, as
MyISAM uses the OS
cache for tables
• myisam_use_mmap
enables MyISAM to use
memory mapping
(7-40% speed
improvement)
• key_cache_segments =
1 enables segmented key
caches in MariaDB -
~250% improvements, as
it mitigates thread
contention for key cache
lock
48

MyISAM segmented key
caches
• Mitigates thread contention for key cache lock, with
notable performance improvements
• Key caches divided into different segments, allowing
for better key cache concurrency
• 1-64 segments
49

InnoDB
• Maintains its own buffer pool (does
aggressive memory caching)
• Uses tablespaces (several ﬁles on disk, raw
disk support)
• Typically used for OLTP operations
50

ARCHIVE
• Store large amounts of data without
indexes, in small disk footprint
• SELECT and INSERT operations only
• Good for data audit use
• Uses AZIO (zlib) compression
51

FederatedX
• Create logical pointers to tables that exist on other MySQL servers;
these can then be linked together to form one logical database
• A federated table pointing to an InnoDB table on another server, will
have transaction support (in 5.1)
• Capabilities limited to underlying engine on remote server
• CREATE TABLE t1 (...) ENGINE=FEDERATED
CONNECTION='mysql://username:pwd@myhost:3306/db_name/
tbl_name
• Can also be used for synchronous replication
• Federated table on master server pointing to slave; triggers on
master table to write all changes to remote table once applied to
the master
52

Memory
• Previously known as HEAP tables
• In-memory engine
• Hash index used by default (changes in 5.2,
enable much better INSERT performance),
B-Tree available too
• https://mariadb.com/kb/en/performance-of-
memory-tables/
53

Aria
• Based off the 5.1 code
• 1.0 – crash-safe MyISAM, with cacheable row format
• 1.5 – concurrent INSERT/SELECT
• Soon to be merged into 6.0, then...
• 2.0: transactional + ACID compliance
• 3.0: high concurrency, online backup
• Goal:ACID compliant, MVCC transactional storage engine, based on MyISAM
• Target? Data warehousing
• Uses big log ﬁles (1GB by default)
• 8K pages used by default (MyISAM uses 1K pages)
• Has group commit (MariaDB 5.2) to speed up inserts
54

PBXT (deprecated)
• MVCC, transactional,ACID compliant, foreign key
support
• row-level locking for updates, so maximum concurrency
• immediate notiﬁcation if client processes are
deadlocked
• write-once, as it uses a log-based architecture (write
data to DB without ﬁrst writing to transaction log)
• support for BLOB streaming with Blob Streaming
engine
55

Storage Engine API
• http://dev.mysql.com/tech-resources/
articles/creating-new-storage-engine.html
• SHOW PLUGINS;
• https://kb.askmonty.org/v/extending-create-
table
• storage/example/ha_example.cc and
storage/example/ha_example.h
56

Writing your own
• Find the plugin path - show variables like “%plugin%”;
+-----------------+-----------------------------------------------+
| Variable_name | Value |
+-----------------+-----------------------------------------------+
| plugin_dir | /usr/local/Cellar/mariadb/10.0.15/lib/plugin/ |
| plugin_maturity | unknown |
+-----------------+-----------------------------------------------+
• note that this is also where you store UDFs
• Copy the relevant engine (eg. myengine.so)
• INSTALL PLUGIN myengine SONAME 'myengine.so';
• Server registers plugin to mysql.plugin table, and now ENGINE=myengine will work
57

Things to think about
• Backup is not engine-independent
• MyISAM, InnoDB,TokuDB
• LVM/ZFS snapshots mitigate this
• Different engines have different monitoring
options
• Mix and match; use summary tables
58

Survey of popular OSS
tools - what they use
• Wordpress (blog): uses default engine, MyISAM is ﬁne
• MediaWiki (wiki): prefers InnoDB, except for
“searchindex” table, which is MyISAM
• http://svn.wikimedia.org/viewvc/mediawiki/trunk/
phase3/maintenance/tables.sql?view=markup
• vBulletin (forum): MyISAM
• SugarCRM (CRM): MyISAM (with conversion script to
InnoDB provided)
• Zimbra Collaboration Suite: InnoDB
59

Now, let’s focus on
MariaDB features
60

We start with...
• What came in 5.1, 5.2, 5.3, 5.5 (jump
around appropriately)
• What comes in 10.0 series
• I won’t talk about deprecated features like
PBXT in-depth, or even the old MariaDB
5.1 pool of threads (5.5 threadpool is
better + improvements in 10.1)
61

XtraDB
• A more performant
InnoDB designed to
scale on modern
hardware
• Less checkpointing
(smoother), less ﬂushing
to disk
62

InnoDB notes
• SHOW GLOBALVARIABLES LIKE ‘innodb_ver
%';
• Important - ship XtraDB and merge with
different Percona Server versions
• eg. innodb_adaptive_flushing_method - native|
estimate|keep_average - where was reflex?
• (okay, 5.6 compatibility,
innodb_adaptive_flushing eventually)
63

InnoDB Fake Changes
• InnoDB Fake Changes for replication pre-
fetching (for DML operations)
• Great for buffer pool warmup
• Consider using multi-threaded slaves in 10.2
• https://www.percona.com/doc/percona-
server/5.6/management/
innodb_fake_changes.html
64

Log archiving
• Log archiving (use to create incremental
backups with xtrabackup)
• When log archiving is enabled, it duplicates
all redo log writes in a separate set of ﬁles
in addition to normal redo log writing,
creating new ﬁles as necessary.
server/5.6/management/log_archiving.html
65

SHOW ENGINE
INNODB STATUS
• Extended, reorganised
• Information about internal hash tables
Internal hash tables (constant factor + variable
factor)
Adaptive hash index 2446944 (2213368 + 233576)
Page hash 139112 (buffer pool 0 only)
Dictionary cache 788235 (554768 + 233467)
File system 829168 (812272 + 16896)
Lock system 333592 (332872 + 720)
Recovery system 0 (0 + 0)
66

Count InnoDB
deadlocks
• Show deadlocks since the server has
started
• SHOW GLOBAL STATUS LIKE
‘innodb_deadlocks';
• + SHOW ENGINE INNODB MUTEX;
67

Further reading
• Multiple Adaptive Hash Search Partitions
server/5.6/scalability/
innodb_adaptive_hash_index_partitions.ht
ml
• Improved InnoDB I/O Scalability
server/5.6/scalability/innodb_io.html
68

Switching between
XtraDB & InnoDB
mysqld --ignore-builtin-innodb --plugin-
load=innodb=ha_innodb.so --plugin_dir=/usr/local/
mysql/lib/mysql/plugin
Or in my.cnf
[mysqld]
ignore-builtin-innodb
plugin-load=innodb=ha_innodb.so
plugin_dir=/usr/local/mysql/lib/mysql/plugin
69

Usernames
• Usernames in MariaDB > 5.5.31? 80 character limit (which
you have to reload manually)
create user
'long12345678901234567890'@'localhost'
identified by 'pass';
Query OK, 0 rows affected (0.01 sec)
vs
ERROR 1470 (HY000): String
'long12345678901234567890' is too long for
user name (should be no longer than 16)
70

MariaDB 5.5: an
opensource threadpool
• Modiﬁed from 5.1 (libevent
based), great for CPU
bound loads and short
running queries
• No minimization of
concurrent transactions
with dynamic pool size
• thread_handling=po
ol-of-threads
• https://mariadb.com/kb/en/
mariadb/thread-pool-in-
mariadb/
71

Improved threadpool
• You can limit resources used by threads:
thread_pool_max_threads
• SHOW GLOBALVARIABLES LIKE
'%thread_%';
72

Better for DBAs: async
client library
• start operation, do work
in thread, operation
processed, result travels
back
• use cases: multiple
queries against single
server (utilize more
CPUs); queries against
multiple servers
(SHOW STATUS on
many machines)
• https://
kb.askmonty.org/en/
about-non-blocking-
operation-in-the-
client-library/
• fast node.js driver
available: mariasql
• https://
kb.askmonty.org/en/
mariasql-for-nodejs/
73

LIMIT ROWS
EXAMINED
• The purpose of this
optimization is to
provide the means to
terminate the execution
of SELECT statements
which examine too
many rows, and thus use
too many resources.
•SELECT * from
t1, t2 LIMIT 10
ROWS EXAMINED
1000;
• https://kb.askmonty.org/
en/limit-rows-examined/
74

SHOW STATUS
• SHOW STATUS provides server status
information. It is like mysqladmin extended-status.
•SHOW STATUS LIKE ‘Key%’;
• https://kb.askmonty.org/en/show-status/
• https://kb.askmonty.org/en/server-status-variables/
• MariaDB has opened_views, executed_triggers,
executed_events, feature_* as new options
75

SQL Error Logging
Plugin
• Log errors sent to clients in a log ﬁle that
can be analysed later. Log ﬁle can be rotated
(recommended)
• a MYSQL_AUDIT_PLUGIN
install plugin SQL_ERROR_LOG
soname 'sql_errlog.so';
76

Audit Plugin
• Log server activity - who connects to the
server, what queries run, what tables touched -
rotating log ﬁle or syslogd
• MariaDB has extended the audit API, so user
ﬁltering is possible
• a MYSQL_AUDIT_PLUGIN
INSTALL PLUGIN server_audit SONAME
‘server_audit.so’;
77

Replication: selective
skipping
• All changes that are logged as events in the
binlog are replicated to all slaves
• However, sometimes you want all to be logged
to binlog but skipped replication to slaves
• @@skip_replication (session only)
• replicate_events_marked_for_skip
= replicate|filter_on_slave|
filter_on_master (dynamic)
78

Replication: dynamic
variables
• The variables replicate_do_*,
replicate_ignore_*, and replicate_wild_*
have been made dynamic, so they can be
changed without requiring a server restart.
• https://kb.askmonty.org/en/dynamic-
replication-variables/
79

Replication:Annotation
of RBR events
• MariaDB supports statement & row based
replication (RBR)
• In RBR, the binlog has no SQL statements,
only events are logged (INSERT, DELETE, etc)
• Option to include original SQL statement
(default OFF)
• https://kb.askmonty.org/en/
annotate_rows_log_event/
80

Replication: binlog
event checksums
• Backport from MySQL 5.6 (in MariaDB
5.3+)
• binlog_checksum option
• Slaves perform checksums on events
received & will stop if there is corruption
• https://kb.askmonty.org/en/binlog-event-
checksums/
81

Replication: group
commit in the binary log
•sync_binlog=1,
innodb_flush_log_at_trx_commit
=1
• https://www.facebook.com/note.php?
note_id=10150261692455933
• http://kb.askmonty.org/en/group-commit-for-
the-binary-log
• SHOW STATUS LIKE 'binlog_%commits';
82

Group commit in
MariaDB 5.3 onwards
• Do slow part of prepare() in parallel in
InnoDB (ﬁrst fsync(), InnoDB group
commit)
• Put transaction in queue, decide commit
order
83

• First in queue runs serial part for all, rest
wait
• Wait for access to the binlog
• Write transactions into binlog, in order,
then sync (second fsync())
• Run the fast part of commit() for all
transactions in order
84

• Finally, run the slow part of commit() in
parallel (third fsync(), InnoDB group
commit)
• Only 2 context switches per thread (one
sleep, one wakeup)
• Note: MySQL 5.6, MariaDB 10 only does 2
fsyncs/group commit
85

Group commit in
MariaDB 10
• Remove commit in slow part of InnoDB
commit (stage 4)
• Reduce cost of crash-safe binlog
• A binlog checkpoint is a point in the
binlog where no crash recovery is
needed before it. In InnoDB you wait for
ﬂush + fsync its redo log for commit
86

crash-safe binlog
• MariaDB 5.5 checkpoints after every
commit —> quite expensive!
• 5.5/5.6 stalls commits around binlog rotate,
waiting for all prepared transactions to
commit (since crash recovery can only scan
latest binlog ﬁle)
87

crash-safe binlog 10.0
• 10.0 makes binlog checkpoints
asynchronous
• A binlog can have no checkpoints at all
• Ability to scan multiple binlogs during
crash recovery
• Remove stalls around binlog rotates
88

Extensions to the SE
API
• prepare() - write prepared trx in
parallel w/group commit
• prepare_ordered() - called serially, in
commit order
• commit_ordered() - called serially, in
commit order; fast commit to memory
• commit() - commit to disk in parallel,
89

group commit in 10.1
• Tricky locking issues hard to change without getting deadlocks
sometimes
• mysql#68251, mysql#68569
• New code? Binlog rotate in background thread (further reducing
stalls). Split transactions across binlogs, so big transactions do not
lead to big binlog ﬁles
• Enhanced semi-sync replication (wait for slave before commit on
the master rather than after commit)
90

Replication: START TRANSACTION
WITH CONSISTENT SNAPSHOT
• Works with the binlog, possible to obtain the binlog position
corresponding to a transactional snapshot of the database without
blocking any other queries.
• by-product of group commit in the binlog to view commit
ordering
• Used by the command mysqldump--single-transaction
--master-data to do a fully non-blocking backup
• Works consistently between transactions involving more than one
storage engine
• https://kb.askmonty.org/en/enhancements-for-start-transaction-
with-consistent/
91

GIS support!
• MySQL has OpenGIS SFS (Simple feature access,
SQL access method)
• Now, SQL with full geometry types
• ST_ preﬁx (incl. ST_RELATE,
ST_BOUNDARY, etc.)
• MyISAM,Aria for SPATIAL & non-spatial indexes
• When 5.7-InnoDB is merged, it will get
support too
92

GIS II
• Spatial reference systems support
(REF_SYSTEM_ID) can be speciﬁed as a column
attribute
• INFORMATION_SCHEMA.GEOMETRY_COLUMN
S for queries of references
• Use Osmosis, you can load all OpenStreetMap data
into MariaDB now
• https://mariadb.com/kb/en/gis-features-in-533/
• https://mariadb.com/kb/en/openstreetmap-dataset/
93

Progress reporting
• ALTER TABLE & LOAD DATA INFILE
MariaDB [mail]> alter table mail engine = maria;
Stage: 1 of 2 'copy to tmp table' 17.55% of stage done
MariaDB [mail]> select id, user, db, command, state,
-> time_ms, progress from information_schema.processlist;
+---------+-------------------+-----------+----------+
| command | state | time_ms | progress |
+---------+-------------------+-----------+----------+
| Query | copy to tmp table | 23407.131 | 17.551 |
+---------+-------------------+-----------+----------+
1 row in set (0.47 sec)
94

TIME_MS in
I_S.PROCESSLIST
• Extra column 'TIME_MS' has been added to
the
INFORMATION_SCHEMA.PROCESSLIST
table
• Units of milliseconds with microsecond
precision (the unit and precision of the
'TIME' column is one second).
95

10.1 I_S.PROCESSLIST
| TIME_MS | decimal(22,3) | NO | | 0.000 | |
| STAGE | tinyint(2) | NO | | 0 | |
| MAX_STAGE | tinyint(2) | NO | | 0 | |
| PROGRESS | decimal(7,3) | NO | | 0.000 | |
| MEMORY_USED | int(7) | NO | | 0 | |
| EXAMINED_ROWS | int(7) | NO | | 0 | |
| QUERY_ID | bigint(4) | NO | | 0 | |
| INFO_BINARY | blob | YES | | NULL | |
+---------------+---------------+------+-----+---------+-------+
97

New KILL syntax
• HARD | SOFT & USER USERNAME are MariaDB-speciﬁc
(5.3.2)
• KILL QUERY ID query_id (10.0.5) - kill by query id, rather
than thread id
• SOFT ensures things that may leave a table in an inconsistent
state aren’t interrupted (like REPAIR or INDEX creation for
MyISAM or Aria)
KILL [HARD | SOFT] [CONNECTION | QUERY]
[thread_id | USER user_name]
98

Statistics
• Understand server activity better to understand database loads
•SET GLOBAL userstat=1;
•SHOW CLIENT_STATISTICS; SHOW USER_STATISTICS;
• # of connections, CPU usage, bytes received/sent, row statistics
•SHOW INDEX_STATISTICS; SHOW TABLE_STATISTICS;
• # rows read, changed, indexes
• INFORMATION_SCHEMA.PROCESSLIST has MEMORY_USAGE,
EXAMINED_ROWS (similar with SHOW STATUS output)
99
MariaDB 10.0+

The old days
• Download MySQL, including sources
• Download SphinxSE for compiling
• Download Sphinx to compile with MySQL
support
• Documented: http://www.howtoforge.com/
sphinx-as-mysql-storage-engine-sphinxse
101

Today
• Install sphinx from your distribution
• Install MariaDB 5.5 from your distribution
or from http://mariadb.org/
• Get started!
102

Getting started
mysql> INSTALL PLUGIN sphinx
SONAME 'ha_sphinx.so';
Query OK, 0 rows affected
(0.01 sec)
103

What is SphinxSE?
• SphinxSE is just the storage engine that still
depends on the Sphinx daemon
• It doesn’t store any data itself
• Its just a built-in client to allow MariaDB to
talk to Sphinx searchd, run queries, obtain
results
• Indexing, searching is performed on Sphinx
105

Conﬁgure sphinx!
• /usr/local/sphinx/sphinx.conf
• Source (multiple, include mysql, with
connection info)
• Setup indexer (esp. if its on localhost) -
mem_limit, max_iops, max_iosize
• Setup searchd (where to listen to, query
log, etc.)
106

Use case scenarios
• Already have an existing application that
makes use of full-text-search in MyISAM?
Porting should be easier
• Have a programming language without a
native API for Sphinx? Surely there’s a
connector for MariaDB ;-)
107

Use case scenarios
• Results from Sphinx itself almost always
require additional work involving MariaDB
• Say to pull out text column that Sphinx
index doesn’t store
• JOIN with another table (using a different
engine)
108

An example
CREATE TABLE t1
(
id INTEGER UNSIGNED NOT NULL,
weight INTEGER NOT NULL,
query VARCHAR(3072) NOT NULL,
group_id INTEGER,
INDEX(query)
) ENGINE=SPHINX CONNECTION="sphinx://localhost:9312/test";
SELECT * FROM t1 WHERE query='test it;mode=any';
109

Sphinx search tables
• 1st column: INTEGER UNSIGNED or
BIGINT (document ID)
• 2nd column: match weight
• 3rd column: VARCHAR or TEXT (your
query)
• Query column needs indexing, no other
column needs to be
110

What actually happens
• SELECT passes a Sphinx query as the query
column in the WHERE clause
• searchd returns the results
• SphinxSE translates and returns the results
to MariaDB
111

What queries are
supported?
• Most of the Sphinx API is exposed to SphinxSE
• query, mode, sort, offset, limit, index, minid,
maxid, weights, ﬁlter, !ﬁlter, range, !range,
maxmatches, groupby, groupsort, indexweights,
comment, select
• Sphinx search modes can also be supported via
_sph attributes
• obtain value of @groupby? use ‘_sph_groupby’
113

Efﬁciency
• Allow Sphinx to perform sorting, ﬁltering, and slicing
of result set
• ... as opposed to using WHERE, ORDER BY, LIMIT
clauses on MariaDB
• Why?
• Sphinx optimises and performs better on these
tasks
• Less data packed by searchd, and transferred and
unpacked by SphinxSE
114

JOINs
• Perform JOINs on a SphinxSE search table using tables from other engines
SELECT content, date_added FROM test.documents docs
-> JOIN t1 ON (docs.id=t1.id)
-> WHERE query="one document;mode=any";
+-------------------------------------+---------------------+
| content | docdate |
+-------------------------------------+---------------------+
| this is my test document number two | 2006-06-17 14:04:28 |
| this is my test document number one | 2006-06-17 14:04:28 |
+-------------------------------------+---------------------+
115

Statistics
• Understand server activity better to understand database loads
•SET GLOBAL userstat=1;
•SHOW CLIENT_STATISTICS; SHOW USER_STATISTICS;
• # of connections, CPU usage, bytes received/sent, row statistics
•SHOW INDEX_STATISTICS; SHOW TABLE_STATISTICS;
• # rows read, changed, indexes
• INFORMATION_SCHEMA.PROCESSLIST has MEMORY_USAGE,
EXAMINED_ROWS (similar with SHOW STATUS output)
116
MariaDB 10.0+

Table Elimination
• Resolve a query without accessing some
tables query refers to
• Great for querying highly normalised data
• Basis of “anchor modelling”
• http://www.anchormodeling.com/
• SQL Server 2005/2008, Oracle 11g have it
117

Virtual columns
• A column in a table that has its value
automatically calculated either with a pre-
calculated/deterministic expression or values
of other ﬁelds in the table
• PERSISTENT (computed when data is inserted
or stored in a table) orVIRTUAL (like aVIEW)
• Similar to MS SQL or Oracle
• https://kb.askmonty.org/en/virtual-columns/
118

Optimizer
enchancements
• Join additions
• block nested loop joins for outer-joins, block hash joins,
Batched Key Access (BKA)
• Optimization for derived tables & views
• mergeable derived tables processed likeVIEWs +
optimizer creates indexes over materialized derived
tables
• Disk access optimization
• Index Condition Pushdown (ICP), Multi-Range Read
(MRR)
119

Subquery optimizations
• Semi-join optimization,
materialization for non-
correlated IN queries,
subquery cache
• Goodbye rewriting as
JOINs or separate
queries
DBT-3, 60M rows, 29GB XtraDB
120

EXPLAIN
• INSTANT EXPLAIN
• EXPLAIN Analyzer -
https://mariadb.org/
explain_analyzer/
analyze/
• Optimizer feature
comparison matrix:
https://kb.askmonty.org/
en/optimizer-feature-
comparison-matrix/
• optimizer_switch
meanings: https://
mariadb.com/kb/en/
mariadb-53-
optimizer_switch/
122

DBT-3
• https://mariadb.com/kb/
en/dbt-3-dataset/
• https://blog.mariadb.org/
mariadb-5-3-optimizer-
benchmark/
123

Extended keys
• Default is extended_keys=on
• Extended Keys, introduced in MariaDB 5.5, is an
optimization which makes use of existing
components of InnoDB/XtraDB keys to generate
more efﬁcient execution plans. Using these
components in many cases allows the server to
generate execution plans which employ index-
only look-ups.
• https://mariadb.com/kb/en/extended-keys/
124

NoSQL: HandlerSocket
• Comes with HandlerSocket
• direct access to XtraDB/InnoDB for
CRUD operations
• INSTALL PLUGIN handlersocket
SONAME 'handlersocket.so';
• This allows applications to
communicate more directly with
MySQL storage engines, without the
overhead associated with using SQL.
This includes operations such as
parsing and optimising queries, as
well as table handling operations
(opening, locking, unlocking, closing).
125

NoSQL: dynamic
columns
• Allows you to create virtual columns with dynamic content for
each row in table
• Basically a BLOB with handling functions
• Store different attributes for each item (like a web store). Hard to
do relationally
• In MariaDB 10.0: name support (instead of referring to columns by
numbers, name it), convert all dynamic column content to JSON
array, interface with Cassandra
• INSERT INTO tbl SET
dyncol_blob=COLUMN_CREATE("column_name", "value");
• https://kb.askmonty.org/en/dynamic-columns/
126

Pluggable
authentication
• MariaDB & MySQL now uses password
authentication via pluggable auth
• Unix sockets
• PAM
127

auth_socket
• Authenticates against the Unix socket ﬁle
• Uses so_peercred socket option to
obtain information about user running client
•CREATE USER ‘byte’@‘localhost’
IDENTIFIED with auth_socket;
• Refuses connection of any other user but
byte from connecting
128

PAM Authentication
• MySQL PAM
• Percona PAM (auth_pam &
auth_pam_compat)
• MariaDB PAM (pam)
129

Let’s get somethings
out of the way
• PAM = Pluggable Authentication Module
• Use pam_ldap to to authenticate
credentials against LDAP server —
conﬁgure /etc/pam_ldap.conf (you also
obviously need /etc/ldap.conf)
• Simplest way is of course /etc/shadow auth
130

MariaDB
INSTALL SONAME ‘auth_pam’;
CREATE USER byte IDENTIFIED via pam
USING ‘mariadb’;
Edit /etc/pam.d/mariadb:
auth required
pam_unix.so
account required
pam_unix.so
131

For MySQL
compatibility
• Just use —pam-use-cleartext-
plugin for MySQL to use
mysql_cleartext_password instead of dialog
plugin
132

Possible errors
• Connectors don’t support it:
• Client does not support authentication
protocol requested by server; consider
upgrading MySQL client.
• You really have to re-compile connector
using libmysqlclient to have said support
133

Why MariaDB 10.0?
• The 5.5 merge took about a year (!)
• We (MariaDB-5.5) have over 1.5 million
lines of extra code with a ~61MB diff
• We didn’t want to repeat this for 5.6
• Also, MySQL 5.6 has a lot of re-factoring,
thus loosing commit history
135

In a nutshell
• Built on MariaDB 5.5
• Backported features from MySQL 5.6
• New features
136

What about tools?
• SELECTVERSION() will
return 10.0.1-MariaDB
• Oops, we found a bug in
MySQL: https://
mariadb.atlassian.net/
browse/MDEV-4088 &
http://bugs.mysql.com/
bug.php?id=68187
• Still deciding:
• Use 9.0 for a name
• Lie to clients (no)
• Disallow replication
(no)
• Use handshake packet
5.5.30-mysql-10.0.2-
MariaDB without
affectingVERSION() /
@@global.version
137

What about tools II?
• Tools really should recognise MariaDB
version as there are already many new
features that MySQL doesn’t have
• eg. HeidiSQL supports virtual columns
(http://www.heidisql.com/forum.php?
t=8671)
138

Backported features
(i.e. these are from MySQL 5.6)
139

InnoDB & XtraDB
• MariaDB 10.0 ships InnoDB from MySQL 5.6
• MariaDB 10 ships Percona XtraDB as default
• minimal performance improvements expected,
just functionality & features
• bitmap changed page tracking so xtrabackup
can do incremental backups without scanning
all InnoDB ﬁles
• SHOW GLOBALVARIABLES LIKE 'innodb_ver%';
140

More from MySQL 5.6
• PERFORMANCE_SCHEMA
• InnoDB read-only transactions (TRANSACTION READ
ONLY)
• Optimizer:
• EXISTS-TO-IN optimization
• ORDER BY...LIMIT optimization (show only few rows
of a result set)
• CURRENT_TIMESTAMP as DEFAULT for DATETIME
columns (this is a re-implementation in MariaDB)
141

In MariaDB 10.0
the new stuff!
142

MariaDB 10 replication
• Global Transaction ID
• have complex replication topologies; simple failover & slave promotion
• doesn’t require restarts!
• new slave provisioning: SET GLOBAL GTID_SLAVE_POS =
BINLOG_GTID_POS("masterbin.00045", 600); CHANGE MASTER TO
master_host="192.168.2.4", master_use_gtid=slave_pos; START
SLAVE;
• turning on GTID for slaves: STOP SLAVE 
CHANGE MASTER TO master_use_gtid=current_pos; START SLAVE;
• change masters: STOP SLAVE 
CHANGE MASTER TO master_host="10.2.3.5"; START SLAVE;
• Crash-safe slaves - GTID position stored in InnoDB table
143

Why different GTID
compared to 5.6?
• MySQL 5.6 GTID does not support multi-
source replication
• Supports —log-slave-updates=0 for
efﬁciency
• Enabled by default
144

Binlog (size matters!)
• Example query: INSERT INTO t1VALUES
(10,“foo”);
• MySQL 5.6… 265 bytes
• MariaDB 10.0… 161 bytes
145

Crash-safe slave (w/
InnoDB DML)
• Replace non-transactional ﬁle relay_log.info
with transactional
mysql.rpl_slave_state
• Changes to rpl_slave_state are
transactionally recovered after crash along
with user data.
146

Replication domains
• Keep central concept that replication is just applying events
in-order from a serial binlog stream.
• Allow multi-source replication with multiple active masters
• Let’s the DBA conﬁgure multiple independent binlog streams
(one per active master: mysqld --git-domain-id=#)
• Events within one stream are ordered the same across
entire replication topology
• Events between different streams can be in different order
on different servers
• Binlog position is one ID per replication domain
147

Parallel replication
• Multi-source replication from different masters executed
in parallel
• Queries from different domains are executed in parallel
• Queries that are run in parallel on the master are run in
parallel on the slave (based on group commit).
• Transactions modifying the same table can be updated
in parallel on the slave!
• Supports both statement based and row based replication.
148

Multi-source replication
• Work from Taobao
• Many users partition data across many masters... now you
can replicate many masters to a single slave
• Great for analytical queries, complete backups, etc.
• @@default_master_connection contains current
connection name (used if connection name is not given)
• All master/slave commands take a connection name now
(like CHANGE MASTER “connection_name”, SHOW SLAVE
“connection_name” STATUS, etc.)
• https://kb.askmonty.org/en/multi-source-replication/
149

Only in 10.0
• SHOW EXPLAIN for
<thread_id> (https://
mariadb.com/kb/en/show-
explain/) gets the query plan
of a running statement
• EXPLAIN ANALYZE
• Faster ALTER TABLE with
unique keys for Aria &
MyISAM
• Segmented MyISAM
keycaches (up to 64) since
MariaDB 5.2 exist too
• Per-thread memory usage
(Taobao)
• I_S.PROCESSLIST has
MEMORY_USAGE &
EXAMINED_ROWS
• SHOW STATUS has
memory usage too
150

SHUTDOWN
• shuts down the server; requires GRANTs
similar to mysqladmin shutdown command
• you can create an event that does a
SHUTDOWN of the server as an
example…
• https://mariadb.com/kb/en/shutdown/
151

CassandraSE
• Integration with NoSQL/Big Data DB,Apache Cassandra cluster,
seen as a storage engine to MariaDB
• Combine (join) data between Cassandra & MariaDB
• Write to Cassandra from SQL (SELECT, INSERT, UPDATE,
DELETE)
• CQL is great, but the goal is for you to just work with SQL, not
switch between CQL & SQL
• Data is mapped: rowkey, static columns, dynamic columns
• super columns aren’t supported
• No 1-1 direct map for data types (ref: https://kb.askmonty.org/en/
cassandra-storage-engine/)
153

TokuDB
• Opensource - separate MariaDB 5.5+TokuDB/
integrated in 10.0.5
• Improved insert (10-20x faster) & query speed,
compression (up to 90% space reduction),
replication performance and online schema
ﬂexibility
• Uses Fractal Tree Indexes instead of B-Tree
• Tests & builds of TokuDB on multiple platforms
(think greater distribution)
154

CONNECT
• CONNECT will speak XML or even grab
data over an ODBC connection
• You can CONNECT to Oracle (via
ODBC), join results from Cassandra (via
CassandraSE) and have all your results sit in
InnoDB
• Turn on engine condition pushdown (10.1
not required)
155

SPIDER
• Spider has built-in sharding features
• Partitioning & XA transaction capable
• Different MariaDB instance tables handled
like it is the same instance
156

Engine-independent
persistent statistics
• InnoDB has persistent statistics in MySQL
5.6; we have an engine-independent version
• These statistics aren’t limited by the SE API,
and are used by query optimizer to choose
best execution plan for each statement
• Statistics collected for non-indexed
columns too (unlike InnoDB’s)
157

MariaDB 10.0.2
• Support for atomic writes on FusionIO
DirectFS
• Optimizer collects & can use histogram-based
statistics for non-indexed columns
• Better table discovery, so FederatedX has
assisted discovery, Sequence engine (creates
ascending/descending sequences, useful in joins)
• SHOW PLUGINS SONAME;
158

MariaDB 10.0.4
• SPIDER storage engine for database sharding
merged
• Audit plugin
• complete PERFORMANCE_SCHEMA
• INFORMATION_SCHEMA with upstream
defaults too
• Online ALTER for InnoDB and thread
information for in-place operations
159

MariaDB 10.0.5
• Parallel replication - https://mariadb.com/
kb/en/parallel-replication/
• automatically detect independent
transactions, parallel within same table,
adapts to master load, and preserves
commit ordering
• EXPLAIN in the slow query log
160

MariaDB 10.0.6
• Serious incompatibility and data corruption
of DATETIME and DATE types due to
get_innobase_type_from_mysql_type
refactor combined with InnoDB Online DDL
• https://mariadb.atlassian.net/browse/
MDEV-5248
• Fixed upgrades from MySQL 5.1 -> MariaDB
• Parallel replication improvements
161

MariaDB 10.0.7
• Mostly bug ﬁxes, to stabilise the code
• XtraDB 5.6 merged (InnoDB still default)
• OQGraph v3 - stores data on disk,
persistent, larger graph support
• INFORMATION_SCHEMA.METADATA_L
OCK_INFO plugin to see active metadata
locks
162

PCRE Regular
Expressions
• Powerful REGEXP/RLIKE operator
• New operators:
• REGEXP_REPLACE(sub,pattern,replace)
• REGEXP_INSTR(sub,pattern)
• REGEXP_SUBSTR(sub,pattern)
• Works with multi-byte character sets that
MariaDB supports, including East-Asian sets
163

Roles
• Bundles users together, with similar
privileges - follows the SQL standard
CREATE ROLE audit_bean_counters;
GRANT SELECT ON accounts.* to
audit_bean_counters;
GRANT audit_bean_counters to
ceo;
164

MariaDB 10.0.9 (RC)
• InnoDB 5.6.15 (XtraDB
default; InnoDB plugin)
• Extended keys
optimization on by
default
• MASTER_GTID_WAIT(
) + @@last_gtid
• TIME casted to
DATETIME, date is
CURRENT_DATE not
0000-00-00 - SQL
standards compliant
• @@old_mode=ZER
O_DATE_TIME_CAS
T
165

MariaDB 10.0.10 (GA)
• audit plugin now ships
• XtraDB performance ﬁxed incorrect
calculation of ﬂushed pages
• TokuDB compression is now
TOKUDB_ZLIB
• Engine independent table statistics
improved
166

Galera Cluster
integrated
• Full integration of Galera Cluster 3.9 (will be 4) into
MariaDB 10.1 — it won’t be a separate download
• no lost transactions
• optimisations for WAN replication
• non-blocking DDL
• no limits on transaction size
•Server version: 10.1.3-MariaDB-wsrep MariaDB
Server, wsrep_25.10.r4144
• Granular monitoring in INFORMATION_SCHEMA —
WSREP_MEMBERSHIP, WSREP_STATUS
168

Encryption
• Encryption: tablespace and table level encryption with
support for rolling keys using the AES algorithm
• table encryption — PAGE_ENCRYPTION=1
• tablespace encryption — encrypts everything including
log ﬁles
• New file_key_management_filename,
file_key_management_filekey,
file_key_management_encryption_algorithm
• Well documented — https://mariadb.com/kb/en/mariadb/
data-at-rest-encryption/
169

Encryption II
• The key ﬁle contains encryption keys
identiﬁers (32-bit numbers) and hex-
encoded encryption keys (128-256 bit
keys), separated by a semicolon.
• don’t forget to create keys!
• eg. openssl enc -aes-256-cbc -
md sha1 -k secret -in
keys.txt -out keys.enc
170

my.cnf conﬁg
[mysqld]
plugin-load-add=file_key_management.so
file-key-management
file-key-management-filename = /home/mdb/keys.enc
innodb-encrypt-tables
innodb-encrypt-log
innodb-encryption-threads=4
aria-encrypt-tables=1 # PAGE row format
encrypt-tmp-disk-tables=1 # this is for Aria
171

Encryption III
CREATE TABLE customer (
customer_id bigint not null primary
key,
customer_name varchar(80),
customer_creditcard varchar(20))
ENGINE=InnoDB
page_encryption=1
page_encryption_key=1;
172

Encryption IV
• Tablespace encryption (Google)
• again, you need to pick an encryption algorithm
• specify what to encrypt: innodb-encrypt-tables,
aria, aria-encrypt-tables, encrypt-
tmp-disk-tables, innodb-encrypt-log
• don’t forget key rotation:
•innodb-encryption-threads=4
•innodb-encryption-rotate-key-
age=1800
173

EncryptionV
• we also have tablespace scrubbing
• background process that regularly scans
through the tables and upgrades the
encryption keys
• scrubbing works for tablespaces and logs
• —encrypt-tmp-ﬁles
• —encrypt-binlog
174

EncryptionVI
•/etc/my.cnf.d/enable_encryption.preset
• Consider using Eperi Gateway for Databases
• MariaDB Enterprise has a plugin for Amazon Key
Management Server (KMS)
• mysqlbinlog has no way to read (i.e. decrypt) an
encrypted binlog
• This does not work with MariaDB Galera Cluster yet
(gcache is not encrypted yet), and also xtrabackup needs
additional work (i.e. if you encrypt the redo log)
175

Optimistic parallel
replication
• Before, transactions committed in parallel on the
master could be run in parallel
• Now, more than one transaction will be
considered to be run in parallel giving another
performance boost in master-to-slave replication
• We have to check if this only will work with a 10.1
master
• Isn’t fully pushed (or documented) yet — see:
https://mariadb.atlassian.net/browse/MDEV-6676
176

Threadpool
• thread_pool_high_prio_mode
• thread_pool_high_prio_tickets
• MDEV-5533
• This brings in improvements made in
Percona Server to the threadpool
177

InnoDB improvements
• Multi-threaded ﬂush (also in 5.7, different
implementation)
• Page compression (optimised for Flash, SSD, FusionIO)
• 64KB pages in InnoDB (old limit = 16KB).
• Defragementation (FB, backported by DaumKakao)
• Forced primary key
• If option is true, create table without primary key or
unique key where all keyparts are NOT NULL is not
accepted. Instead an error message is printed.
178

InnoDB WebScaleSQL
• MDEV-6936: Buffer pool list scan optimisation
• MDEV-6929: Port Facebook Prefix Index Queries Optimization
• MDEV-6932: Enable Lazy Flushing
• MDEV-6931: Page cleaner should do LRU flushing regardless of server
activity
• fixes mysql#71988, mysql#70500
• DB-746 merge clustering key is covering key for mariadb 10 (TokuDB)
• MDEV-6933: Spurious lock_wait_timeout_thread wakeup in
lock_wait_suspend_thread()
• fixes mysql#72123
179

Per query variables
• Long history (http://www.bytebot.net/blog/
archives/2014/05/04/per-query-variable-
settings-in-mysqlpercona-
serverwebscalesql)
•SET STATEMENT
max_statement_time=1000 FOR
SELECT name FROM name ORDER
BY name;
180

Statement timeouts
• from Twitter patch; re-written by monty
• MAX_STATEMENT_TIME to abort long
running queries
• We call it “query timeouts” + have a
different syntax
MDEV-4427
181

Optimiser
enhancements
• UNION ALL without temporary tables (5.7)
• Improve ORDER BY in optimiser
• Mostly there is EXPLAIN JSON (like 5.6)*
• EXPLAIN ANALYZE with FORMAT=JSON
• includes data from the query execution itself —
this is MariaDB only
• https://mariadb.com/kb/en/mariadb/analyze-
formatjson-examples/
182

EXPLAIN ANALYZE
MariaDB [information_schema]> explain format=json select * from
all_pluginsG
*************************** 1. row ***************************
EXPLAIN: {
"query_block": {
"select_id": 1,
"table": {
"table_name": "all_plugins",
"access_type": "ALL"
}
}
}
1 row in set (0.01 sec)
183

WebScaleSQL
• WebScaleSQL improvements
MDEV-6039
• Lots of running thru AddressSanitizer
(ASan)
• Many of these also get backported to
10.0.13
184

Passwords
• Password validation plugin exists now
• https://mariadb.com/kb/en/mariadb/development/mariadb-
internals-documentation/password-validation/
• simple_password_check password validation plugin
• can enforce a minimum password length and guarantee that a
password contains at least a speciﬁed number of uppercase
and lowercase letters, digits, and punctuation characters.
• cracklib_password_check password validation plugin
• Allows passwords that are strong enough to pass CrackLib
test.This is the same test that pam_cracklib.so does
185

Audit plugin
improvements
• Monitor access, locate errors, etc.
• Connection — connect/disconnect/failed;
Query — DDL/DML+TCL/DCL; Object —
Database/Tables
• Passwords in 1.2 replaced by a placeholder
(ﬁltered, i.e. not in audit log)
186

CONNECT
• CONNECT having full JSON/BSON support
• Can read filename.json files with ease
• Writing — INSERT, UPDATE, DELETE is
supported — however, if you have added/
modified values for objects or arrays, there
can be complications (similar like the XML
type object issue)
• Works with Sveta’s JSON UDFs as well
187

Other bits
• Slaves can execute triggers now
• Dump thread enhancements (remove binlog
lock LOCK_log) from 5.7 included (Google)
• CREATE or REPLACE for most database
objects minus indexes
• SET DEFAULT ROLE (there is a default role
now for current user)
188

Other bits
• FRM ﬁles are now not created for temporary
tables
• INFORMATION_SCHEMA.SYSTEM_VARIABLES
- information for system variables
• Compiled with security hardening options (fortify
source - https://mariadb.atlassian.net/browse/
MDEV-5730)
• @@sql_log_slow can now be controlled on a
session basis (not just globally)
189

GIS
• Full compliance for the OGC standards around GIS.
• yes, we are missing a few functions, but its likely to
improve
• MDEV-4045 Missing OGC Spatial functions.
• MDEV-60 Support for Spatial Reference systems for the
GIS data.
• MDEV-12 OpenGIS: create required tables:
GeometryColumns, related views.
• Speaking shortly, the MariaDB GIS part is now OpenGIS
compliant, and passes all the OpenGIS conformance tests
190

Kerberos/GSSAPI
• Every participant in authenticated communication is
known as a ‘principal’ (w/unique name)
• Principals belong to administrative groups called
realms. Kerberos Distribution Centre maintains a
database of principal in realm + associated secret keys
• Client requests a ticket from KDC for access to a
speciﬁc asset. KDC uses the client’s secret and the
server’s secret to construct the ticket which allows
the client and server to mutually authenticate each
other, while keeping the secrets hidden.
191

MariaDB Kerberos
plugin
• User principals: <username>@<KERBEROS
REALM>
•CREATE USER 'byte' IDENTIFIED VIA
kerberos AS ‘byte/mariadb@lp';
• so that is <username>/
<instance>@<KERBEROS REALM>
• Store Service Principal Name (SPN) is an option
in a conﬁg ﬁle
192

Works where?
• GSSAPI-based Kerberos widely used &
supported on Linux
• Windows supports SSPI authentication and
the plugin supports it
• Comes with MariaDB Server 10.1
193

Show list of compiled-
in locales
• INSTALL SONAME 'locales';
SELECT * FROM INFORMATION_SCHEMA.LOCALES;
+-----+-------+-------------------------------------+-----------------------
+---------------------+---------------+--------------+------------------------+
| ID | NAME | DESCRIPTION | MAX_MONTH_NAME_LENGTH |
MAX_DAY_NAME_LENGTH | DECIMAL_POINT | THOUSAND_SEP | ERROR_MESSAGE_LANGUAGE |
+-----+-------+-------------------------------------+-----------------------
+---------------------+---------------+--------------+------------------------+
| 0 | en_US | English - United States | 9 |
9 | . | , | english |
| 1 | en_GB | English - United Kingdom | 9 |
9 | . | , | english |
| 2 | ja_JP | Japanese - Japan | 3 |
3 | . | , | japanese |
194

Still use the query
cache?
• Show the contents of the query cache
• Querying the table acquires the QC lock, so lock
waits for queries using/expiring QC
• INSTALL PLUGIN query_cache_info SONAME
‘query_cache_info';
• select statement_schema, statement_text,
result_blocks_count,
• result_blocks_size from
information_schema.query_cache_info;
195

Query response time
• (range_base ^ n; range_base ^ (n+1)]
• INSTALL SONAME ‘query_response_time';
• SHOW QUERY_RESPONSE_TIME;
server/5.6/diagnostics/
response_time_distribution.html
196

Compatibility
• Temporary tables are stored in Aria but now there
is a —default-tmp-storage-engine option
• engine_condition_pushdown ﬂag removed (its
always on for engines that support it)
• --mysql56-temporal-format option to use the
MySQL-5.6 low level formats to store TIME,
DATETIME and TIMESTAMP types
• PERFORMANCE_SCHEMA disabled by default
like in 10.0
197

Caveats (for 100%
compatibility)
• GTID implemented differently from 5.6
• InnoDB memcached
• Optimizer trace
• mysqlbinlog streaming server
• Time-delayed replication
198

Looking forward to
MariaDB Server 10.2
• mysqlbinlog streaming server backup
• Window functions
• CREATE USER for limiting resource usage
• Virtual column improvements
• EXPLAIN JSON gets better
• Common Table Expressions
199

Support
• Five years from every release
• MariaDB 5.5 in Red Hat Enterprise Linux 7
• MariaDB 10 in SUSE Enterprise Linux 12
200

Benchmarks
• “Lies, damned lies, and statistics” - Mark Twain
• http://blog.mariadb.org/sysbench-oltp-
mysql-5-6-vs-mariadb-10-0/
• http://dimitrik.free.fr/blog/archives/2013/02/
mysql-performance-mysql-56-vs-mysql-55-
vs-mariadb-55.html
• One thing is clear: there needs to be more
benchmarking done
201

MariaDB deployed
“MariaDB had these same bugs that we ran into with
MySQL. However the big difference was that when we
reported these bugs, they were quickly resolved within 48
hours!” -- Dreas van Donselaar, Chief Technology Ofﬁcer,
SpamExperts
B.V. after migrating over 300 servers from MySQL 5.0
to MariaDB 5.1.
“Migrating from MySQL 5.1 to MariaDB 5.2 was as simple
as removing MySQL RPMs and installing the MariaDB
packages, then running mysql_upgrade.” - Panayot Belchev,
proprietor, Host Bulgaria on providing
MariaDB to over 7,000 of their web hosting customers.
“We made the switch on Saturday --
and we’re seeing beneﬁts already -- our
daily optimization time is down from
24 minutes to just 4 minutes” -- Ali
Watters, CEO, travelblog.org
happy users: pap.fr, Paybox Services, OLX, Jelastic,
Web of Trust,Wikipedia, Craigslist, etc.
“@nginxorg & @mariadb
have helped me save
$12000/year in
infrastructure cost. I love it!
Do more with less!” -
Ewdison Then, CEO,
Slashgear
We upgraded the support.mozilla.org
databases from Percona 5.1 to MariaDB 5.5.
One of the engineers and I had a
conversation where he mentioned that “one
of our worst performing views on SUMO is
doing waaaayyy better with the upgraded
databases”, that it “seems more stable” and
that “I stopped receiving ‘MySQL went away
or disconnected emails’ which came in once
in a while.” - Sheeri Cabral, Mozilla IT
202

Resources
• http://mariadb.org/
• https://mariadb.com/kb/en/
• http://planet.mysql.com/
• http://planetmariadb.org/
203

Books!
1. MariaDB Crash Course, Ben Forta (September 2011)
2. Getting Started with MariaDB, Daniel Bartholomew (October 2013)
3. MariaDB Cookbook, Daniel Bartholomew (March 2014)
4. Real MariaDB, Matt Lee (April 2014)
5. Building a Web Application with PHP & MariaDB:A Reference Guide,
Sai Srinivas Sriparasa (June 2014)
6. MariaDB: Beginners Guide, Rodrigo Ribeiro (August 2014)
7. Mastering MariaDB, Federico Razzioli (September 2014)
8. MariaDB High Performance, Pierre Mavro (September 2014)
9. Learning MySQL & MariaDB, Russell Dyer (April 2015)
204

Q&A
colin.charles@percona.com | byte@bytebot.net
slides: slideshare.net/bytebot
http://bytebot.net/blog/ | @bytebot on twitter
http://www.percona.com/
206

The Complete MariaDB Server tutorial

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