What's new in MySQL 5 - PerconaWhat's new in MySQL 5.7 Marcos Albe Percona University Montevideo,...
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What's new in MySQL 5.7 Marcos Albe Percona University Montevideo, April 2014
Transcript of What's new in MySQL 5 - PerconaWhat's new in MySQL 5.7 Marcos Albe Percona University Montevideo,...
What's new in MySQL 5.7
Marcos AlbePercona University
Montevideo, April 2014
www.percona.com
Agenda
● InnoDB
● Replication
● PERFORMANCE_SCHEMA
● Operational
● Command line client (mysql)
● Security
● Miscellaneous
www.percona.com
Foreword
● 5.7 work in progress... so doublecheck!
● Not trying to be exhaustive... read manual!
● Good job Oracle! (hope to see tests code free soon)
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InnoDB improvements
● Multiple page_cleaner threads for [dirty] buffer pool flushing – Set with innodb_page_cleaners = N
● Enhanced buffer pool dump and load operations – Set with innodb_buffer_pool_dump_pct
– Throttled by innodb_io_capacity
● Supports rebuilding regular and partitioned tables using ALGORITHM=INPLACE with: OPTIMIZE TABLE ALTER TABLE ... FORCE ALTER TABLE ... ENGINE=INNODB
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InnoDB improvements II
● Doublewrite disabled devices with atomic writes. – Been here, done that:
http://www.percona.com/doc/percona-server/5.5/performance/atomic_fio.html ;-)
– Awesome stuff that increases value and lifetime of very expensive hardware.
● InnoDB Monitor uses vars instead of tables– innodb_monitor => innodb_status_output
– innodb_lock_monitor => innodb_status_output_locks
● Reworked GIS (spatial data types) for InnoDB
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InnoDB improvements III
● Improved DDL performance for InnoDB temporary tables
● New ibtmp1 for non-compressed temporary tables– innodb_temp_data_file_path
– Keeps new type of non-redo undo log for temporary tables
● Temporary table metadata is no longer stored to InnoDB system tables– now in I_S.INNODB_TEMP_TABLE_INFO
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InnoDB improvements IV
● Enhanced innochecksum – Supports files > 2GB
– Can rewrite [invalid] checksums with --write
– Tablespace stats: --page-type-summary (woohoo!) ================PAGE TYPE SUMMARY============== #PAGE_COUNT PAGE_TYPE =============================================== 2 Index page 0 Undo log page 1 Inode page 0 Insert buffer free list page 2 Freshly allocated page 1 Insert buffer bitmap 0 System page 0 Transaction system page 1 File Space Header 0 Extent descriptor page 0 BLOB page 0 Compressed BLOB page 0 Other type of page
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Replication improvements I
● Different method for parallel replication (slave-parallel-type)– DATABASE: thread-per-schema
– LOGICAL_CLOCK: time hints ● Timestamp information stored by the master● Tells slaves when it is safe to run threads in parallel:
"The timestamp identifies the last transaction committed at the time that the current transaction entered the prepare stage, and all transactions having the same timestamp can execute in parallel"
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Replication improvements II
● Refactored master's dump thread– Reduce lock contention/improve throughput
– Multiple dump threads are now able to read concurrently
– Dump threads are now able to read while clients are writing
● More flexibility with Semi-synchronous replication– rpl_semi_sync_master_wait_for_slave_count (was fixed to 1
before)
– rpl_semi_sync_master_wait_point (AFTER_SYNC / AFTER_COMMIT)
– Separate threads for sending/receiving semisynchronous replication acknowledgement signals
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Replication improvements III
● Database name rewriting with mysqlbinlog – ROW based replication only
– --rewrite-db='dboldname->dbnewname'
– Can be specified multiple times
● CHANGE REPLICATION FILTER statement
– Allows to dynamically set replication filtering rules
– STOP SLAVE SQL_THREAD before changing
– START SLAVE SQL_THREAD after changing
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Replication improvements IV
● Can CHANGE MASTER TO without [full] STOP SLAVE– If SQL thread stopped: can change RELAY_LOG_FILE,
RELAY_LOG_POS, and MASTER_DELAY
– If IO thread stopped: can change any options except above ones
– Both threads stopped: MASTER_AUTO_POSITION=1
● Non-blocking SHOW SLAVE STATUS\G
● A warning is emitted after STOP SLAVE+CHANGE MASTER when Slave_open_temp_tables > 0 (SBR)
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'mysql' client improvements
● Ctrl-C works as expected now!!– Aborts query or input line
– Does NOT quit client
● The "mysql" client now has a --syslog option that sends interactive statements to system's syslog – Suppressed for statements matching default "ignore" pattern
("*IDENTIFIED*:*PASSWORD*")
– Suppressed for any patterns specified using the --histignore
● Now the --ssl option enfornces SSL (previously it was advisory)
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Custom full-text parsing
● Full-text parser plugins;
● Two possible roles:– Replace parser (i.e. how text is converted to words)
– Translate for parser (from PDF, DOC, XML, etc.)
– Can do both roles
● Plugin per-index:
CREATE TABLE t ( doc CHAR(255), FULLTEXT INDEX (doc) WITH PARSER my_parser) ENGINE=InnoDB;
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Miscellaneous improvements I
● EXPLAIN FOR CONNECTION <connection id>
● EXPLAIN includes “cost information” (use JSON format)
● EXPLAIN PARTITIONS/EXTENDED always enabled
● Ability to set timeout for SELECTs– Per statement: SELECT MAX_STATEMENT_TIME = 5000 id,
name FROM my_table...
– Global/session: max_statement_time
● Multiple triggers per event/time– added trigger_order to triggers syntax
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Miscellaneous improvements II
● Strict sql_mode (STRICT_ALL_TABLES|STRICT_TRANS_TABLES) now implies– ERROR_FOR_DIVISION_BY_ZERO
– NO_ZERO_DATE
– NO_ZERO_IN_DATE
● Less verbose bootstrap (a.k.a. mysql_install_db)\– Avoid missing important messages
● MTR uses InnoDB as default storage engine.– Better testing for InnoDB in general
– More code coverage
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PERFORMANCE_SCHEMA I
● Memory usage instrumentation!!! – Helps to understand/tune the memory consumption
– Helps find memory leaks
– New P_S tables● memory_summary_global_by_event_name ● memory_summary_by_account_by_event_name ● memory_summary_by_host_by_event_name ● memory_summary_by_thread_by_event_name ● memory_summary_by_user_by_event_name
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PERFORMANCE_SCHEMA II
● Transactions instrumentation!!!
– Transaction latency
– Isolation levels
– Auto-commit
– Rollback savepoints info
– GTID/Transaction IDs
– Link transactions to statements!.
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PERFORMANCE_SCHEMA III
● New P_S tables for transactions instrumentationb– events_transactions_current
– events_transactions_history
– events_transactions_history_long
– events_transactions_summary_by_account_by_event_name
– events_transactions_summary_by_host_by_event_name
– events_transactions_summary_by_thread_by_event_name
– events_transactions_summary_by_user_by_event_name
– events_transactions_summary_global_by_event_name
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PERFORMANCE_SCHEMA IV
● Replication configuration and status exposed in tables
– Superset for SHOW SLAVE STATUS
– Good for monitoring and failover trickery...but still lacks master status!! (as noted by Giusseppe)
● New P_S tables– replication_connection_configuration
– replication_connection_status
– replication_execute_configuration
– replication_execute_status
– replication_execute_status_by_coordinator
– replication_execute_status_by_worker
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Security changes I
● Impacts 5.1/5.5/5.6 to 5.7 upgrades– Rows in mysql.user must have nonempty plugin column
– Default_authentication_plugin
● Ability to set policy for automatic password expiration– Default_password_lifetime
– Disconnect_on_expired_password
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Security changes II
● Secured installation by default– Can disable with --skip-random-passwords
● Single root account 'root'@'localhost'– Random expired password for this account.
– Random password saved in $HOME/.mysql_secret
● No anonymous-user accounts.
● No “test” database.
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Partitioning improvements
● Improved Transportable Tablespace feature – Supports partitioned tables
– Supports individual table partitions.
● Index condition pushdown support for partitioned tables (InnoDB/MyISAM)
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Operational improvements
● Online ALTER TABLE for RENAME INDEX
– Change is made in place
– no table-copy operation
– Works for all storage engines
● VARCHAR size may be increased with ALTER TABLE ... ALGORITHM=INPLACE [InnoDB only]
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Questions
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