Percona Server 8.0

© 2016 Percona© 2016 Percona© 2016 Percona© 2016 Percona© 2016 Percona© 2016 Percona© 2016 Percona1
Laurynas Biveinis
Percona Server 8.0
Technical Director @ Percona
Percona Live Europe 2018
2018-11-06

First of all, what is Percona Server?
“…a free, fully compatible, enhanced and open source drop-in replacement
for any MySQL database…”

© 2018 Percona3
Percona Server 5.7 user:
▪Percona Server 8.0 
= Percona Server 5.7 
+ MySQL 8.0
Two Ways to Define Percona Server 8.0
New / MySQL 8.0 user:
▪Percona Server 8.0  
= MySQL 8.0 
+ enhancements

© 2018 Percona4
For a Percona Server 5.7 user:
▪Percona Server 8.0 
= Percona Server 5.7 
+ MySQL 8.0
▪In other words, “what has changed in Percona additions since Percona
Server 5.7?”
We will focus on the latter definition

© 2018 Percona
What has changed since Percona Server 5.7?
▪Features dropped
▪Features adjusted to work with MySQL 8.0 features
Does the above list seem to miss anything?
▪“Features added?”
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© 2018 Percona
MySQL GA features over time
6
Generallyavailablefeatures
MySQL 5.5 MySQL 5.6 MySQL 5.7 MySQL 8.0

© 2018 Percona
Percona Server GA additions over time
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GenerallyavailablePerconafeatures
PS 5.5 PS 5.6 PS 5.7 PS 8.0

Deprecated feature removal
They had it coming

© 2018 Percona
Scalability metrics plugin
Subtly broken architecture that is not easy to fix
No users we are aware of
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© 2018 Percona
INFORMATION_SCHEMA.THREAD_STATISTICS:
CONCURRENT_CONNECTIONS column
How to define it for thread_statistics in the first place?
The value was zero for years and nobody noticed (or
everybody did and were OK with it)
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© 2018 Percona
innodb_kill_idle_transactions variable
▪Only the variable, the feature is not deprecated
▪Accessible through kill_idle_transactions variable
▪Drop the innodb_ prefix to upgrade (on 5.7 already!)
▪A remnant of generalisation of the feature from InnoDB to all SEs
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© 2018 Percona
Query Cache enhancements
▪log_slow_filter=qc_miss
▪QC_hit in the slow query log extensions
▪query_cache_strip_comments system variable
▪“Waiting for query cache mutex” thread state in the processlist
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Features removed due to upstream
What is the upgrade path?

© 2018 Percona
Query Response Time plugin
Use Performance Schema execution time histograms
▪Before:
• SELECT * from INFORMATION_SCHEMA.QUERY_RESPONSE_TIME
▪After:
• SELECT COUNT(*) FROM
performance_schema.events_statements_histogram_global GROUP BY
COUNT_BUCKET
• … many other possibilities
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© 2018 Percona
LOCK BINLOG FOR BACKUP
Query performance_schema.log_status instead
▪Before:
• Use Percona XtraBackup
▪After:
• Use Percona XtraBackup, an 8.0-compatible version (8.0-3-rc1 as of today)
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© 2018 Percona
innodb_flush_method = ALL_O_DIRECT
Set it to something else, O_DIRECT most likely
▪Before:
• Use innodb_flush_method=ALL_O_DIRECT to avoid having redo logs in the
kernel FS cache
▪After:
• Oracle MySQL 8.0 redo logging is dependent on having logs in the FS cache
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© 2018 Percona
Memory summary in SHOW ENGINE INNODB
STATUS
Query
performance_schema.memory_summary_global_by_event_name
instead
▪ Before:
Internal hash tables (constant factor + variable factor)
Adaptive hash index 2266736 (2213368 + 53368)
Page hash 139112 (buffer pool 0 only)
Dictionary cache 729463 (554768 + 174695)
File system 824800 (812272 + 12528)
Lock system 333248 (332872 + 376)
Recovery system 0 (0 + 0)
Dictionary memory allocated 174695
▪ After:
• Query PFS memory summary tables
• Beware of MySQL bug 90561, fixed in 8.0.13
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Features removed due to lack of uptake
Let us know if you are a user!

© 2018 Percona
Features removed due to lack of uptake
▪INFORMATION_SCHEMA.XTRADB_RSEG
▪Expanded program option modifiers
▪Utility user
▪pseudo_server_id
▪CSV_MODE
▪max_slowlog_files and max_slowlog_size
▪innodb_show_verbose_locks
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Changed features
What is the upgrade path?

© 2018 Percona
No more legacy partitioning in 8.0
Percona Server 8.0: native partitioning for MyRocks and
TokuDB
Partitioned tables must be upgraded before the upgrade
to 8.0
Hence, Percona Server 5.7 also features native
partitioning
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© 2018 Percona
The biggest upstream game-changer: new DD
Atomic DDL, no more FRM files, 1 billion tables…
TokuDB ROW_FORMAT clause removed, use
tokudb_row_format system variable
CREATE COMPRESSION DICTIONARY json_keys (‘name’,
‘city’, … ) reimplemented in the new DD
Expanded fast index creation will be soon
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© 2018 Percona
SET STATEMENT FOR →/* SET_VAR */
Percona Server 5.7 (and MariaDB) per-statement variable
assignments:
▪SET STATEMENT sort_buffer_size=100000 FOR SELECT name …
MySQL 8.0 variable-setting optimizer hint
▪SELECT /*+ SET_VAR(sort_buffer_size=100000)*/ name …
Percona Server has extended SET_VAR to cover the
majority of SET STATEMENT use cases
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© 2018 Percona
“userstat” duration columns now floating-point
INFORMATION_SCHEMA.CLIENT_STATISTICS,
THREAD_STATISTICS, USER_STATISTICS:
CONNECTED_TIME, BUSY_TIME, CPU_TIME
▪Percona Server 5.7: integers, 1s resolution,
▪Percona Server 8.0: double precision
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© 2018 Percona
SHOW [EFFECTIVE] GRANTS
MySQL 5.7 SHOW GRANTS
▪ Shows assigned but not effective grants
Percona Server 5.7 SHOW GRANTS
▪ The above was considered a bug
▪ Shows effective but not assigned grants
Percona Server 8.0 SHOW [EFFECTIVE] GRANTS
▪ The above was considered a bug
▪ SHOW GRANTS: shows assigned grants
▪ SHOW EFFECTIVE GRANTS: shows effective grants
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© 2018 Percona
Binlog space management
Percona Server 5.7: max_binlog_files
▪Manage max space in combination with max_binlog_size
▪Was not reliable due to extra rotations
Percona Server 8.0: binlog_space_limit
▪binlog_space_limit=10G - works alone, easier to manage
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© 2018 Percona
Percona Server 8.0: RC1 as of today
RC1 released last week
We are still exploring 8.0 performance
Questions?
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Percona Server 8.0

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