News

FromDual Ops Center for MySQL and compatible databases 1.0.0 has been released

Shinguz - Mon, 2020-05-11 15:58

FromDual has the pleasure to announce the release of the new version 1.0.0 of its popular FromDual Ops Center focmm, a Graphical User Interface (GUI) for MySQL and compatible databases.

The FromDual Ops Center for MySQL and compatible databases (focmm) helps DBA's and System Administrators to better manage their MySQL and compatible databases farms. Ops Center makes DBA and Admins life easier!

The main task of Ops Center is to support you in your daily MySQL and compatible databases operation tasks. More information about FromDual Ops Center you can find here.

Download

The new FromDual Ops Center for MySQL and compatible databases (focmm) can be downloaded from here. How to install and use focmm is documented in the Ops Center User Guide.

In the inconceivable case that you find a bug in the FromDual Ops Center for MySQL and compatible databases please report it to the FromDual bug tracker or just send us an email.

Any feedback, statements and testimonials are welcome as well! Please send them to feedback@fromdual.com.

Installation of Ops Center 1.0.0

A complete guide on how to install FromDual Ops Center you can find in the Ops Center User Guide.

Upgrade from 0.9.x to 1.0.0

Upgrade from 0.9.x to 1.0.0 should happen automatically. Please do a backup of your Ops Center Instance before you upgrade! Please also check Upgrading.

Changes in Ops Center 1.0.0 Machine

Expression Server replaced by Machine.
Better error handling in getOperatingSystem function.
Machine does not belong to a Cluster any more: Column cluster_id from table machine removed.
Machine rename prepared.
2 bugs on refresh and edit Machine fixed.
Instances added to Machine overview.

Instance

Expression Node replaced by Instance.
Instance added to Machine and Cluster overview.
Database Account management implemented.
Bug in create instance (server_id) fixed.
Bugs fixed in Instance backup, Instance restore, Instance performance and create Account.
Variable skip_name_resolve added to create Instance. This makes error probability smaller for accounts with same username but different host.
Menu title Configuration renamed to Settings.
Configuration file management implemented.
Deleting Instance belonging to a Cluster is not possible any more. Cluster must first release instance before instance can be deleted.
Column instance_type removed.
Menu Title Variables renamed to Configuration.
Show Processlist refurbished, filter fields smaller and daemon and system users filtered out.
Schema management implemented.
MySQL compatible database version 10.4 defaults for Variables added.
Missing backup-target is only ERR and not EMERG any more.
Instance performance advises added for sar.
Function copyFileFromRemoteServer should preserve timestamp now.
Connection changed from connect to real_connect to allow SSL connections.
SSL connection from Ops Center to Target Database and Repository Database is possible now.

Cluster

CHANGE MASTER TO and Cluster change fixed for systems with more than one Cluster.
CHANGE MASTER TO password is hidden now as well, all password can be viewed and copied.
Cluster bugs fixed.
Cluster functions cleaned-up.
Galera safe to bootstrap improved.
Machine removed from Cluster dashboard.
Instance added to Cluster overview.

Load-Balancer

Better error handling for Load-Balancer.
MaxScale Load-Balancer added in overview.
ProxySQL Load-Balancer basics implemented.

Virtual IP (VIP)/Floating IP

Put Edit VIP buttons in right order.

Tools

Tool for File Transfer added.
Tool config-diff compare button added also to top of table.

Configuration

No changes.

Database-as-a-Service (DBaaS)

Customer group replaced by Resource group.
FK added to Resource costs.
User Group added.
Logout User put into own function.
Tabindex for User edit/add added.
User cannot delete itself any more.
User comment and User group responsibility added.
User is logged out from focmm when deleted.

Building and Packaging

No changes.

Themes / UI

Keybord usage and Tab Index implemented in some forms.
jquery upgraded from 3.4.1 to 3.5.0

General

All HTML code removed in code.
Constant clean-up.
Machine, Instance and Cluster overview are sorted now.
Menu Instance, Machine and Cluster are sorted now, getXxxx function extended to make this possible.
Order of object and function changed in url.
Spell check error fixed.
Title moved a bit more to the right.
All tests passed for MySQL compatible database 10.5 and MySQL 8.0. Both can be considered as supported now.
Repository version 124 added, create separated for next major step.

Taxonomy upgrade extras: Operations release FromDual Ops Center ops center dbaas focmm

FromDual Ops Center for MySQL and compatible databases 1.0.0 has been released

Shinguz - Mon, 2020-05-11 15:58

FromDual has the pleasure to announce the release of the new version 1.0.0 of its popular FromDual Ops Center focmm, a Graphical User Interface (GUI) for MySQL and compatible databases.

The FromDual Ops Center for MySQL and compatible databases (focmm) helps DBA's and System Administrators to better manage their MySQL and compatible databases farms. Ops Center makes DBA and Admins life easier!

The main task of Ops Center is to support you in your daily MySQL and compatible databases operation tasks. More information about FromDual Ops Center you can find here.

Download

The new FromDual Ops Center for MySQL and compatible databases (focmm) can be downloaded from here. How to install and use focmm is documented in the Ops Center User Guide.

In the inconceivable case that you find a bug in the FromDual Ops Center for MySQL and compatible databases please report it to the FromDual bug tracker or just send us an email.

Any feedback, statements and testimonials are welcome as well! Please send them to feedback@fromdual.com.

Installation of Ops Center 1.0.0

A complete guide on how to install FromDual Ops Center you can find in the Ops Center User Guide.

Upgrade from 0.9.x to 1.0.0

Upgrade from 0.9.x to 1.0.0 should happen automatically. Please do a backup of your Ops Center Instance before you upgrade! Please also check Upgrading.

Changes in Ops Center 1.0.0 Machine

Expression Server replaced by Machine.
Better error handling in getOperatingSystem function.
Machine does not belong to a Cluster any more: Column cluster_id from table machine removed.
Machine rename prepared.
2 bugs on refresh and edit Machine fixed.
Instances added to Machine overview.

Instance

Expression Node replaced by Instance.
Instance added to Machine and Cluster overview.
Database Account management implemented.
Bug in create instance (server_id) fixed.
Bugs fixed in Instance backup, Instance restore, Instance performance and create Account.
Variable skip_name_resolve added to create Instance. This makes error probability smaller for accounts with same username but different host.
Menu title Configuration renamed to Settings.
Configuration file management implemented.
Deleting Instance belonging to a Cluster is not possible any more. Cluster must first release instance before instance can be deleted.
Column instance_type removed.
Menu Title Variables renamed to Configuration.
Show Processlist refurbished, filter fields smaller and daemon and system users filtered out.
Schema management implemented.
MySQL compatible database version 10.4 defaults for Variables added.
Missing backup-target is only ERR and not EMERG any more.
Instance performance advises added for sar.
Function copyFileFromRemoteServer should preserve timestamp now.
Connection changed from connect to real_connect to allow SSL connections.
SSL connection from Ops Center to Target Database and Repository Database is possible now.

Cluster

CHANGE MASTER TO and Cluster change fixed for systems with more than one Cluster.
CHANGE MASTER TO password is hidden now as well, all password can be viewed and copied.
Cluster bugs fixed.
Cluster functions cleaned-up.
Galera safe to bootstrap improved.
Machine removed from Cluster dashboard.
Instance added to Cluster overview.

Load-Balancer

Better error handling for Load-Balancer.
MaxScale Load-Balancer added in overview.
ProxySQL Load-Balancer basics implemented.

Virtual IP (VIP)/Floating IP

Put Edit VIP buttons in right order.

Tools

Tool for File Transfer added.
Tool config-diff compare button added also to top of table.

Configuration

No changes.

Database-as-a-Service (DBaaS)

Customer group replaced by Resource group.
FK added to Resource costs.
User Group added.
Logout User put into own function.
Tabindex for User edit/add added.
User cannot delete itself any more.
User comment and User group responsibility added.
User is logged out from focmm when deleted.

Building and Packaging

No changes.

Themes / UI

Keybord usage and Tab Index implemented in some forms.
jquery upgraded from 3.4.1 to 3.5.0

General

All HTML code removed in code.
Constant clean-up.
Machine, Instance and Cluster overview are sorted now.
Menu Instance, Machine and Cluster are sorted now, getXxxx function extended to make this possible.
Order of object and function changed in url.
Spell check error fixed.
Title moved a bit more to the right.
All tests passed for MySQL compatible database 10.5 and MySQL 8.0. Both can be considered as supported now.
Repository version 124 added, create separated for next major step.

Taxonomy upgrade extras: Operations release FromDual Ops Center ops center dbaas

Categories: FromDual all (en), FromDual TechFeed (en), MySQL Tech-Feed (en)

FromDual Ops Center for MySQL and compatible databases 1.0.0 has been released

Shinguz - Mon, 2020-05-11 15:58

FromDual has the pleasure to announce the release of the new version 1.0.0 of its popular FromDual Ops Center focmm, a Graphical User Interface (GUI) for MySQL and compatible databases.

The FromDual Ops Center for MySQL and compatible databases (focmm) helps DBA's and System Administrators to better manage their MySQL and compatible databases farms. Ops Center makes DBA and Admins life easier!

The main task of Ops Center is to support you in your daily MySQL and compatible databases operation tasks. More information about FromDual Ops Center you can find here.

Download

The new FromDual Ops Center for MySQL and compatible databases (focmm) can be downloaded from here. How to install and use focmm is documented in the Ops Center User Guide.

In the inconceivable case that you find a bug in the FromDual Ops Center for MySQL and compatible databases please report it to the FromDual bug tracker or just send us an email.

Any feedback, statements and testimonials are welcome as well! Please send them to feedback@fromdual.com.

Installation of Ops Center 1.0.0

A complete guide on how to install FromDual Ops Center you can find in the Ops Center User Guide.

Upgrade from 0.9.x to 1.0.0

Upgrade from 0.9.x to 1.0.0 should happen automatically. Please do a backup of your Ops Center Instance before you upgrade! Please also check Upgrading.

Changes in Ops Center 1.0.0 Machine

Expression Server replaced by Machine.
Better error handling in getOperatingSystem function.
Machine does not belong to a Cluster any more: Column cluster_id from table machine removed.
Machine rename prepared.
2 bugs on refresh and edit Machine fixed.
Instances added to Machine overview.

Instance

Expression Node replaced by Instance.
Instance added to Machine and Cluster overview.
Database Account management implemented.
Bug in create instance (server_id) fixed.
Bugs fixed in Instance backup, Instance restore, Instance performance and create Account.
Variable skip_name_resolve added to create Instance. This makes error probability smaller for accounts with same username but different host.
Menu title Configuration renamed to Settings.
Configuration file management implemented.
Deleting Instance belonging to a Cluster is not possible any more. Cluster must first release instance before instance can be deleted.
Column instance_type removed.
Menu Title Variables renamed to Configuration.
Show Processlist refurbished, filter fields smaller and daemon and system users filtered out.
Schema management implemented.
MySQL compatible database version 10.4 defaults for Variables added.
Missing backup-target is only ERR and not EMERG any more.
Instance performance advises added for sar.
Function copyFileFromRemoteServer should preserve timestamp now.
Connection changed from connect to real_connect to allow SSL connections.
SSL connection from Ops Center to Target Database and Repository Database is possible now.

Cluster

CHANGE MASTER TO and Cluster change fixed for systems with more than one Cluster.
CHANGE MASTER TO password is hidden now as well, all password can be viewed and copied.
Cluster bugs fixed.
Cluster functions cleaned-up.
Galera safe to bootstrap improved.
Machine removed from Cluster dashboard.
Instance added to Cluster overview.

Load-Balancer

Better error handling for Load-Balancer.
MaxScale Load-Balancer added in overview.
ProxySQL Load-Balancer basics implemented.

Virtual IP (VIP)/Floating IP

Put Edit VIP buttons in right order.

Tools

Tool for File Transfer added.
Tool config-diff compare button added also to top of table.

Configuration

No changes.

Database-as-a-Service (DBaaS)

Customer group replaced by Resource group.
FK added to Resource costs.
User Group added.
Logout User put into own function.
Tabindex for User edit/add added.
User cannot delete itself any more.
User comment and User group responsibility added.
User is logged out from focmm when deleted.

Building and Packaging

No changes.

Themes / UI

Keybord usage and Tab Index implemented in some forms.
jquery upgraded from 3.4.1 to 3.5.0

General

All HTML code removed in code.
Constant clean-up.
Machine, Instance and Cluster overview are sorted now.
Menu Instance, Machine and Cluster are sorted now, getXxxx function extended to make this possible.
Order of object and function changed in url.
Spell check error fixed.
Title moved a bit more to the right.
All tests passed for MySQL compatible database 10.5 and MySQL 8.0. Both can be considered as supported now.
Repository version 124 added, create separated for next major step.

Taxonomy upgrade extras: Operations release FromDual Ops Center ops center dbaas

Categories: FromDual all (en), FromDual TechFeed (en), MySQL Tech-Feed (en)

Shutdown with MySQL 8

Shinguz - Wed, 2020-04-01 16:52

On StackExchange for Database Administrators I recently have seen a question which attracted my interest.

The question puzzled me a bit because the answer seems too easy. Further the question was not so clear. An all theses factors smell dangerous...

About time - was, is and will be

How can I find out if the database "was" shutdown slowly? This is quite easy: Look into your MySQL Error Log and there you will find a log sequence similar to the following:

2020-03-30T08:03:36.928017Z 0 [System] [MY-010910] [Server] /home/mysql/product/mysql-8.0.19-linux-glibc2.12-x86_64/bin/mysqld: Shutdown complete (mysqld 8.0.19) MySQL Community Server - GPL.

Ups! There are no more "shutting down ..." messages like in MySQL 5.7:

2020-03-30T08:04:49.898254Z 0 [Note] Giving 1 client threads a chance to die gracefully 2020-03-30T08:04:49.898266Z 0 [Note] Shutting down slave threads 2020-03-30T08:04:51.898389Z 0 [Note] Forcefully disconnecting 1 remaining clients 2020-03-30T08:04:51.898433Z 0 [Warning] bin/mysqld: Forcing close of thread 115 user: 'enswitch' 2020-03-30T08:04:51.898512Z 0 [Note] Event Scheduler: Purging the queue. 0 events 2020-03-30T08:04:51.924644Z 0 [Note] Binlog end 2020-03-30T08:04:51.938518Z 0 [Note] Shutting down plugin 'ngram' ... 2020-03-30T08:04:53.296239Z 0 [Note] Shutting down plugin 'binlog' 2020-03-30T08:04:53.296805Z 0 [Note] bin/mysqld: Shutdown complete

So you cannot find out, when shutdown started any more and thus you cannot say how long it took to shutdown MySQL. So MySQL messed it up somehow in 8.0. Too much clean-up!

If you want to get the old behaviour back you can stop MySQL 8 as follows:

SQL> SET GLOBAL log_error_verbosity = 3; SQL> SHUTDOWN;

or just add the variable to your MySQL configuration file (my.cnf).

Then you will find the old shutdown sequence in your error log as before:

2020-03-30T08:13:55.071627Z 9 [System] [MY-013172] [Server] Received SHUTDOWN from user root. Shutting down mysqld (Version: 8.0.19). 2020-03-30T08:13:55.178119Z 0 [Note] [MY-010067] [Server] Giving 1 client threads a chance to die gracefully 2020-03-30T08:13:55.178210Z 0 [Note] [MY-010117] [Server] Shutting down slave threads ... 2020-03-30T08:13:56.588574Z 0 [System] [MY-010910] [Server] /home/mysql/product/mysql-8.0.19-linux-glibc2.12-x86_64/bin/mysqld: Shutdown complete (mysqld 8.0.19) MySQL Community Server - GPL.

If you want to know where your MySQL Error Log File is located you can find it like this:

SQL> SHOW GLOBAL VARIABLES LIKE 'log_error'; +---------------+---------------------------------------------+ | Variable_name | Value | +---------------+---------------------------------------------+ | log_error | /home/mysql/database/mysql-80/log/error.log | +---------------+---------------------------------------------+

Typical locations are: /var/lib/mysql/<hostname>.log or /var/log/mysqld.log or /var/log/mysql/mysqld.log or /var/log/messages or similar.

Now about the "is"

When you are currently shutting down MySQL it is already to late to find it out when it started. Because you cannot connect to the database any more to change the settings and you do not see anything in the MySQL Error log. Possibly you can look at the error log with stat and you can see when the last message was written to it to find the start of the shutdown.

shell> stat error.log File: error.log Size: 29929 Blocks: 64 IO Block: 4096 regular file Device: 801h/2049d Inode: 5373953 Links: 1 Access: (0640/-rw-r-----) Uid: ( 1001/ mysql) Gid: ( 1001/ mysql) Access: 2020-03-30 10:13:59.491446560 +0200 Modify: 2020-03-30 10:13:56.587467485 +0200 Change: 2020-03-30 10:13:56.587467485 +0200 Birth: -

Symptoms for a working shutdown is either heavy writing to disk (iostat -xk 1) or heavy swapping in (vmstat). You have to wait until finished. Some brave people use a kill -9 in such a case, if they have InnoDB only and if they know exactly what they are doing and how much time a following crash recovery will take.

And finally about the question "how long will the shutdown take" (will be)

This is not so easy to predict. It depends on several things:

How many memory blocks of your database are swapped out.
How many pages are dirty and must be written to disk.
How fast is your I/O system (IOPS).

You can gather these information as follows:

How much Swap must be swapped in you can find here.
The number of dirty pages (pages modified but not written to disk yet) you can find with: SQL> SHOW GLOBAL STATUS LIKE 'Innodb_buffer_pool_pages_dirty';
And about the IOPS you have to ask your hardware spec sheet (150 to 100'000 IOPS).

I hope with this answer I have covered all the possibly questions about shutting down MySQL 8.0?

Taxonomy upgrade extras: mysql shutdown slow

Categories: FromDual all (en), FromDual TechFeed (en), MySQL Tech-Feed (en)

Shutdown with MySQL 8

Shinguz - Wed, 2020-04-01 16:52

On StackExchange for Database Administrators I recently have seen a question which attracted my interest.

The question puzzled me a bit because the answer seems too easy. Further the question was not so clear. An all theses factors smell dangerous...

About time - was, is and will be

How can I find out if the database "was" shutdown slowly? This is quite easy: Look into your MySQL Error Log and there you will find a log sequence similar to the following:

2020-03-30T08:03:36.928017Z 0 [System] [MY-010910] [Server] /home/mysql/product/mysql-8.0.19-linux-glibc2.12-x86_64/bin/mysqld: Shutdown complete (mysqld 8.0.19) MySQL Community Server - GPL.

Ups! There are no more "shutting down ..." messages like in MySQL 5.7:

2020-03-30T08:04:49.898254Z 0 [Note] Giving 1 client threads a chance to die gracefully 2020-03-30T08:04:49.898266Z 0 [Note] Shutting down slave threads 2020-03-30T08:04:51.898389Z 0 [Note] Forcefully disconnecting 1 remaining clients 2020-03-30T08:04:51.898433Z 0 [Warning] bin/mysqld: Forcing close of thread 115 user: 'enswitch' 2020-03-30T08:04:51.898512Z 0 [Note] Event Scheduler: Purging the queue. 0 events 2020-03-30T08:04:51.924644Z 0 [Note] Binlog end 2020-03-30T08:04:51.938518Z 0 [Note] Shutting down plugin 'ngram' ... 2020-03-30T08:04:53.296239Z 0 [Note] Shutting down plugin 'binlog' 2020-03-30T08:04:53.296805Z 0 [Note] bin/mysqld: Shutdown complete

So you cannot find out, when shutdown started any more and thus you cannot say how long it took to shutdown MySQL. So MySQL messed it up somehow in 8.0. Too much clean-up!

If you want to get the old behaviour back you can stop MySQL 8 as follows:

SQL> SET GLOBAL log_error_verbosity = 3; SQL> SHUTDOWN;

or just add the variable to your MySQL configuration file (my.cnf).

Then you will find the old shutdown sequence in your error log as before:

2020-03-30T08:13:55.071627Z 9 [System] [MY-013172] [Server] Received SHUTDOWN from user root. Shutting down mysqld (Version: 8.0.19). 2020-03-30T08:13:55.178119Z 0 [Note] [MY-010067] [Server] Giving 1 client threads a chance to die gracefully 2020-03-30T08:13:55.178210Z 0 [Note] [MY-010117] [Server] Shutting down slave threads ... 2020-03-30T08:13:56.588574Z 0 [System] [MY-010910] [Server] /home/mysql/product/mysql-8.0.19-linux-glibc2.12-x86_64/bin/mysqld: Shutdown complete (mysqld 8.0.19) MySQL Community Server - GPL.

If you want to know where your MySQL Error Log File is located you can find it like this:

SQL> SHOW GLOBAL VARIABLES LIKE 'log_error'; +---------------+---------------------------------------------+ | Variable_name | Value | +---------------+---------------------------------------------+ | log_error | /home/mysql/database/mysql-80/log/error.log | +---------------+---------------------------------------------+

Typical locations are: /var/lib/mysql/<hostname>.log or /var/log/mysqld.log or /var/log/mysql/mysqld.log or /var/log/messages or similar.

Now about the "is"

When you are currently shutting down MySQL it is already to late to find it out when it started. Because you cannot connect to the database any more to change the settings and you do not see anything in the MySQL Error log. Possibly you can look at the error log with stat and you can see when the last message was written to it to find the start of the shutdown.

shell> stat error.log File: error.log Size: 29929 Blocks: 64 IO Block: 4096 regular file Device: 801h/2049d Inode: 5373953 Links: 1 Access: (0640/-rw-r-----) Uid: ( 1001/ mysql) Gid: ( 1001/ mysql) Access: 2020-03-30 10:13:59.491446560 +0200 Modify: 2020-03-30 10:13:56.587467485 +0200 Change: 2020-03-30 10:13:56.587467485 +0200 Birth: -

Symptoms for a working shutdown is either heavy writing to disk (iostat -xk 1) or heavy swapping in (vmstat). You have to wait until finished. Some brave people use a kill -9 in such a case, if they have InnoDB only and if they know exactly what they are doing and how much time a following crash recovery will take.

And finally about the question "how long will the shutdown take" (will be)

This is not so easy to predict. It depends on several things:

How many memory blocks of your database are swapped out.
How many pages are dirty and must be written to disk.
How fast is your I/O system (IOPS).

You can gather these information as follows:

How much Swap must be swapped in you can find here.
The number of dirty pages (pages modified but not written to disk yet) you can find with: SQL> SHOW GLOBAL STATUS LIKE 'Innodb_buffer_pool_pages_dirty';
And about the IOPS you have to ask your hardware spec sheet (150 to 100'000 IOPS).

I hope with this answer I have covered all the possibly questions about shutting down MySQL 8.0?

Taxonomy upgrade extras: mysql shutdown slow

Categories: FromDual all (en), FromDual TechFeed (en), MySQL Tech-Feed (en)

Shutdown with MySQL 8

Shinguz - Wed, 2020-04-01 16:52

On StackExchange for Database Administrators I recently have seen a question which attracted my interest.

The question puzzled me a bit because the answer seems too easy. Further the question was not so clear. An all theses factors smell dangerous...

About time - was, is and will be

How can I find out if the database "was" shutdown slowly? This is quite easy: Look into your MySQL Error Log and there you will find a log sequence similar to the following:

2020-03-30T08:03:36.928017Z 0 [System] [MY-010910] [Server] /home/mysql/product/mysql-8.0.19-linux-glibc2.12-x86_64/bin/mysqld: Shutdown complete (mysqld 8.0.19) MySQL Community Server - GPL.

Ups! There are no more "shutting down ..." messages like in MySQL 5.7:

2020-03-30T08:04:49.898254Z 0 [Note] Giving 1 client threads a chance to die gracefully 2020-03-30T08:04:49.898266Z 0 [Note] Shutting down slave threads 2020-03-30T08:04:51.898389Z 0 [Note] Forcefully disconnecting 1 remaining clients 2020-03-30T08:04:51.898433Z 0 [Warning] bin/mysqld: Forcing close of thread 115 user: 'enswitch' 2020-03-30T08:04:51.898512Z 0 [Note] Event Scheduler: Purging the queue. 0 events 2020-03-30T08:04:51.924644Z 0 [Note] Binlog end 2020-03-30T08:04:51.938518Z 0 [Note] Shutting down plugin 'ngram' ... 2020-03-30T08:04:53.296239Z 0 [Note] Shutting down plugin 'binlog' 2020-03-30T08:04:53.296805Z 0 [Note] bin/mysqld: Shutdown complete

So you cannot find out, when shutdown started any more and thus you cannot say how long it took to shutdown MySQL. So MySQL messed it up somehow in 8.0. Too much clean-up!

If you want to get the old behaviour back you can stop MySQL 8 as follows:

SQL> SET GLOBAL log_error_verbosity = 3; SQL> SHUTDOWN;

or just add the variable to your MySQL configuration file (my.cnf).

Then you will find the old shutdown sequence in your error log as before:

2020-03-30T08:13:55.071627Z 9 [System] [MY-013172] [Server] Received SHUTDOWN from user root. Shutting down mysqld (Version: 8.0.19). 2020-03-30T08:13:55.178119Z 0 [Note] [MY-010067] [Server] Giving 1 client threads a chance to die gracefully 2020-03-30T08:13:55.178210Z 0 [Note] [MY-010117] [Server] Shutting down slave threads ... 2020-03-30T08:13:56.588574Z 0 [System] [MY-010910] [Server] /home/mysql/product/mysql-8.0.19-linux-glibc2.12-x86_64/bin/mysqld: Shutdown complete (mysqld 8.0.19) MySQL Community Server - GPL.

If you want to know where your MySQL Error Log File is located you can find it like this:

SQL> SHOW GLOBAL VARIABLES LIKE 'log_error'; +---------------+---------------------------------------------+ | Variable_name | Value | +---------------+---------------------------------------------+ | log_error | /home/mysql/database/mysql-80/log/error.log | +---------------+---------------------------------------------+

Typical locations are: /var/lib/mysql/<hostname>.log or /var/log/mysqld.log or /var/log/mysql/mysqld.log or /var/log/messages or similar.

Now about the "is"

When you are currently shutting down MySQL it is already to late to find it out when it started. Because you cannot connect to the database any more to change the settings and you do not see anything in the MySQL Error log. Possibly you can look at the error log with stat and you can see when the last message was written to it to find the start of the shutdown.

shell> stat error.log File: error.log Size: 29929 Blocks: 64 IO Block: 4096 regular file Device: 801h/2049d Inode: 5373953 Links: 1 Access: (0640/-rw-r-----) Uid: ( 1001/ mysql) Gid: ( 1001/ mysql) Access: 2020-03-30 10:13:59.491446560 +0200 Modify: 2020-03-30 10:13:56.587467485 +0200 Change: 2020-03-30 10:13:56.587467485 +0200 Birth: -

Symptoms for a working shutdown is either heavy writing to disk (iostat -xk 1) or heavy swapping in (vmstat). You have to wait until finished. Some brave people use a kill -9 in such a case, if they have InnoDB only and if they know exactly what they are doing and how much time a following crash recovery will take.

And finally about the question "how long will the shutdown take" (will be)

This is not so easy to predict. It depends on several things:

How many memory blocks of your database are swapped out.
How many pages are dirty and must be written to disk.
How fast is your I/O system (IOPS).

You can gather these information as follows:

How much Swap must be swapped in you can find here.
The number of dirty pages (pages modified but not written to disk yet) you can find with: SQL> SHOW GLOBAL STATUS LIKE 'Innodb_buffer_pool_pages_dirty';
And about the IOPS you have to ask your hardware spec sheet (150 to 100'000 IOPS).

I hope with this answer I have covered all the possibly questions about shutting down MySQL 8.0?

Taxonomy upgrade extras: mysql shutdown slow

Categories: FromDual all (en), FromDual TechFeed (en), MySQL Tech-Feed (en)

innodb_deadlock_detect - Rather Hands off!

Shinguz - Mon, 2020-03-23 11:24

Recently we had a new customer who has had from time to time massive database problems which he did not understand. When we reviewed the MySQL configuration file (my.cnf) we found, that this customer had disabled the InnoDB Deadlock detection (innodb_deadlock_detect).

Because we have advised against doing this so far, but I never stumbled upon this problem in practice, I have investigated a bit more about the MySQL variable innodb_deadlock_detect.

The MySQL documentation tells us the following [1]:

Disabling Deadlock Detection
On high concurrency systems, deadlock detection can cause a slowdown when numerous threads wait for the same lock. At times, it may be more efficient to disable deadlock detection and rely on the innodb_lock_wait_timeout setting for transaction rollback when a deadlock occurs. Deadlock detection can be disabled using the innodb_deadlock_detect configuration option.

And about the parameter innodb_deadlock_detect itself [2] itself:

This option is used to disable deadlock detection. On high concurrency systems, deadlock detection can cause a slowdown when numerous threads wait for the same lock. At times, it may be more efficient to disable deadlock detection and rely on the innodb_lock_wait_timeout setting for transaction rollback when a deadlock occurs.

The problem is, that every time, when MySQL is doing a (Row) Lock or a Table Lock, it checks, if the Lock causes a Deadlock. This check is quite expensive. By the way: The feature disabling InnoDB Deadlock detection was developed by Facebook for WebScaleSQL [3].

The relevant functions can be found in [4]:

class DeadlockChecker, method check_and_resolve (DeadlockChecker::check_and_resolve) Every InnoDB (row) Lock (for mode LOCK_S or LOCK_X) and type ORed with LOCK_GAP or LOCK_REC_NOT_GAP, ORed with LOCK_INSERT_INTENTION Enqueue a waiting request for a lock which cannot be granted immediately. lock_rec_enqueue_waiting()

and

Every (InnoDB) Table Lock Enqueues a waiting request for a table lock which cannot be granted immediately. Checks for deadlocks. lock_table_enqueue_waiting()

This means if the variable innodb_deadlock_detect is enabled (= default) for every Lock (Row or Table) it is checked, if it causes a Deadlock. If the variable is disabled, the check is NOT done (which is faster) and the transaction hangs in (Dead-)Lock until the Lock is freed or the time innodb_lock_wait_timeout (default 50 seconds) is exceeded. Then the InnoDB Lock Wait Timeout (detector?) strikes and kills the transaction.

SQL> SHOW GLOBAL VARIABLES LIKE 'innodb_lock_wait%'; +--------------------------+-------+ | Variable_name | Value | +--------------------------+-------+ | innodb_lock_wait_timeout | 50 | +--------------------------+-------+

This means, deactivating InnoDB Deadlock detection is interesting, if you have many (like Facebook!?!) short and small transactions where you expect little to now conflicts.
Further it is recommended, to set the MySQL variable innodb_lock_wait_timeout to a very small value (some seconds).

Because most of our customers do not have the size of Facebook and because they have rather not so many concurrent short and small transactions but few but long transactions (with probably many Locks and therefore a high Deadlock probability), I can imagine, disabling this parameter was responsible for the hickup (Locks are piling up) of the customer system. Which leads to exceeding max_connections and finally the whole system sticks.

Therefore I strongly recommend, to let InnoDB Deadlock detection enabled. Except you know exactly what your are doing (after about 2 weeks of extensive testing and measuring).

Literature

[1] Deadlock Detection and Rollback
[2] InnoDB Startup Options and System Variables: innodb_deadlock_detect
[3] Introduction of the variable innodb_deadlock_detect in WebScaleSQL by Facebook on Github
[4] MariaDB/MySQL Source Code: storage/innobase/lock/lock0lock.cc
[5] MariaDB InnoDB System Variables: innodb_deadlock_detect

Taxonomy upgrade extras: innodb deadlock lock performance locking block

Categories: FromDual all (en), FromDual TechFeed (en), MySQL Tech-Feed (en)

innodb_deadlock_detect - Rather Hands off!

Shinguz - Mon, 2020-03-23 11:24

Recently we had a new customer who has had from time to time massive database problems which he did not understand. When we reviewed the MySQL configuration file (my.cnf) we found, that this customer had disabled the InnoDB Deadlock detection (innodb_deadlock_detect).

Because we have advised against doing this so far, but I never stumbled upon this problem in practice, I have investigated a bit more about the MySQL variable innodb_deadlock_detect.

The MySQL documentation tells us the following [1]:

Disabling Deadlock Detection
On high concurrency systems, deadlock detection can cause a slowdown when numerous threads wait for the same lock. At times, it may be more efficient to disable deadlock detection and rely on the innodb_lock_wait_timeout setting for transaction rollback when a deadlock occurs. Deadlock detection can be disabled using the innodb_deadlock_detect configuration option.

And about the parameter innodb_deadlock_detect itself [2] itself:

This option is used to disable deadlock detection. On high concurrency systems, deadlock detection can cause a slowdown when numerous threads wait for the same lock. At times, it may be more efficient to disable deadlock detection and rely on the innodb_lock_wait_timeout setting for transaction rollback when a deadlock occurs.

The problem is, that every time, when MySQL is doing a (Row) Lock or a Table Lock, it checks, if the Lock causes a Deadlock. This check is quite expensive. By the way: The feature disabling InnoDB Deadlock detection was developed by Facebook for WebScaleSQL [3].

The relevant functions can be found in [4]:

class DeadlockChecker, method check_and_resolve (DeadlockChecker::check_and_resolve) Every InnoDB (row) Lock (for mode LOCK_S or LOCK_X) and type ORed with LOCK_GAP or LOCK_REC_NOT_GAP, ORed with LOCK_INSERT_INTENTION Enqueue a waiting request for a lock which cannot be granted immediately. lock_rec_enqueue_waiting()

and

Every (InnoDB) Table Lock Enqueues a waiting request for a table lock which cannot be granted immediately. Checks for deadlocks. lock_table_enqueue_waiting()

This means if the variable innodb_deadlock_detect is enabled (= default) for every Lock (Row or Table) it is checked, if it causes a Deadlock. If the variable is disabled, the check is NOT done (which is faster) and the transaction hangs in (Dead-)Lock until the Lock is freed or the time innodb_lock_wait_timeout (default 50 seconds) is exceeded. Then the InnoDB Lock Wait Timeout (detector?) strikes and kills the transaction.

SQL> SHOW GLOBAL VARIABLES LIKE 'innodb_lock_wait%'; +--------------------------+-------+ | Variable_name | Value | +--------------------------+-------+ | innodb_lock_wait_timeout | 50 | +--------------------------+-------+

This means, deactivating InnoDB Deadlock detection is interesting, if you have many (like Facebook!?!) short and small transactions where you expect little to now conflicts.
Further it is recommended, to set the MySQL variable innodb_lock_wait_timeout to a very small value (some seconds).

Because most of our customers do not have the size of Facebook and because they have rather not so many concurrent short and small transactions but few but long transactions (with probably many Locks and therefore a high Deadlock probability), I can imagine, disabling this parameter was responsible for the hickup (Locks are piling up) of the customer system. Which leads to exceeding max_connections and finally the whole system sticks.

Therefore I strongly recommend, to let InnoDB Deadlock detection enabled. Except you know exactly what your are doing (after about 2 weeks of extensive testing and measuring).

Literature

[1] Deadlock Detection and Rollback
[2] InnoDB Startup Options and System Variables: innodb_deadlock_detect
[3] Introduction of the variable innodb_deadlock_detect in WebScaleSQL by Facebook on Github
[4] MariaDB/MySQL Source Code: storage/innobase/lock/lock0lock.cc
[5] MariaDB InnoDB System Variables: innodb_deadlock_detect

Taxonomy upgrade extras: innodb deadlock lock performance locking block

Categories: FromDual all (en), FromDual TechFeed (en), MySQL Tech-Feed (en)

innodb_deadlock_detect - Rather Hands off!

Shinguz - Mon, 2020-03-23 11:24

Recently we had a new customer who has had from time to time massive database problems which he did not understand. When we reviewed the MySQL configuration file (my.cnf) we found, that this customer had disabled the InnoDB Deadlock detection (innodb_deadlock_detect).

Because we have advised against doing this so far, but I never stumbled upon this problem in practice, I have investigated a bit more about the MySQL variable innodb_deadlock_detect.

The MySQL documentation tells us the following [1]:

Disabling Deadlock Detection
On high concurrency systems, deadlock detection can cause a slowdown when numerous threads wait for the same lock. At times, it may be more efficient to disable deadlock detection and rely on the innodb_lock_wait_timeout setting for transaction rollback when a deadlock occurs. Deadlock detection can be disabled using the innodb_deadlock_detect configuration option.

And about the parameter innodb_deadlock_detect itself [2] itself:

This option is used to disable deadlock detection. On high concurrency systems, deadlock detection can cause a slowdown when numerous threads wait for the same lock. At times, it may be more efficient to disable deadlock detection and rely on the innodb_lock_wait_timeout setting for transaction rollback when a deadlock occurs.

The problem is, that every time, when MySQL is doing a (Row) Lock or a Table Lock, it checks, if the Lock causes a Deadlock. This check is quite expensive. By the way: The feature disabling InnoDB Deadlock detection was developed by Facebook for WebScaleSQL [3].

The relevant functions can be found in [4]:

class DeadlockChecker, method check_and_resolve (DeadlockChecker::check_and_resolve) Every InnoDB (row) Lock (for mode LOCK_S or LOCK_X) and type ORed with LOCK_GAP or LOCK_REC_NOT_GAP, ORed with LOCK_INSERT_INTENTION Enqueue a waiting request for a lock which cannot be granted immediately. lock_rec_enqueue_waiting()

and

Every (InnoDB) Table Lock Enqueues a waiting request for a table lock which cannot be granted immediately. Checks for deadlocks. lock_table_enqueue_waiting()

This means if the variable innodb_deadlock_detect is enabled (= default) for every Lock (Row or Table) it is checked, if it causes a Deadlock. If the variable is disabled, the check is NOT done (which is faster) and the transaction hangs in (Dead-)Lock until the Lock is freed or the time innodb_lock_wait_timeout (default 50 seconds) is exceeded. Then the InnoDB Lock Wait Timeout (detector?) strikes and kills the transaction.

SQL> SHOW GLOBAL VARIABLES LIKE 'innodb_lock_wait%'; +--------------------------+-------+ | Variable_name | Value | +--------------------------+-------+ | innodb_lock_wait_timeout | 50 | +--------------------------+-------+

This means, deactivating InnoDB Deadlock detection is interesting, if you have many (like Facebook!?!) short and small transactions where you expect little to now conflicts.
Further it is recommended, to set the MySQL variable innodb_lock_wait_timeout to a very small value (some seconds).

Because most of our customers do not have the size of Facebook and because they have rather not so many concurrent short and small transactions but few but long transactions (with probably many Locks and therefore a high Deadlock probability), I can imagine, disabling this parameter was responsible for the hickup (Locks are piling up) of the customer system. Which leads to exceeding max_connections and finally the whole system sticks.

Therefore I strongly recommend, to let InnoDB Deadlock detection enabled. Except you know exactly what your are doing (after about 2 weeks of extensive testing and measuring).

Literature

[1] Deadlock Detection and Rollback
[2] InnoDB Startup Options and System Variables: innodb_deadlock_detect
[3] Introduction of the variable innodb_deadlock_detect in WebScaleSQL by Facebook on Github
[4] MariaDB/MySQL Source Code: storage/innobase/lock/lock0lock.cc
[5] MariaDB InnoDB System Variables: innodb_deadlock_detect

Taxonomy upgrade extras: innodb deadlock lock performance locking block

Categories: FromDual all (en), FromDual TechFeed (en), MySQL Tech-Feed (en)

FromDual is 10 years old

Shinguz - Mon, 2020-03-02 10:03

On 1 March 2020 FromDual became 10 years old! Sincere thanks are given to all our customers, partners and interested person for their support and good cooperation in the last 10 years. And we would be pleased to advise and support you again competently in the coming 10 years.

Your FromDual Team

Picture by kalhh on Pixabay

Taxonomy upgrade extras: fromdual

Categories: FromDual all (en), FromDual TechFeed (en), MySQL Tech-Feed (en)

FromDual is 10 years old

Shinguz - Mon, 2020-03-02 10:03

On 1 March 2020 FromDual became 10 years old! Sincere thanks are given to all our customers, partners and interested person for their support and good cooperation in the last 10 years. And we would be pleased to advise and support you again competently in the coming 10 years.

Your FromDual Team

Picture by kalhh on Pixabay

Taxonomy upgrade extras: fromdual

Categories: FromDual all (en), FromDual TechFeed (en), MySQL Tech-Feed (en)

FromDual is 10 years old

Shinguz - Mon, 2020-03-02 10:03

On 1 March 2020 FromDual became 10 years old! Sincere thanks are given to all our customers, partners and interested person for their support and good cooperation in the last 10 years. And we would be pleased to advise and support you again competently in the coming 10 years.

Your FromDual Team

Picture by kalhh on Pixabay

Taxonomy upgrade extras: fromdual

Categories: FromDual all (en), FromDual TechFeed (en), MySQL Tech-Feed (en)

InnoDB Page Cleaner intended loop takes too long

Shinguz - Tue, 2020-02-18 17:50

Recently we migrated a database system from MySQL 5.7 to MariaDB 10.3. Everything went fine so far just the following message started to pop-up in the MariaDB Error Log File with the severity Note:

InnoDB: page_cleaner: 1000ms intended loop took 4674ms. The settings might not be optimal. (flushed=102 and evicted=0, during the time.)

I remember that this message also appeared in earlier MySQL 5.7 releases but somehow disappeared in later releases. I assume MySQL has just disabled the Note?

You can find various advices in the Internet on to get rid of this Note:

innodb_lru_scan_depth = 1024, 256 innodb_buffer_pool_instances = 1, 8 innodb_io_capcity = 100, 200 or 1000 innodb_page_cleaners = 1, 4 or 8

But non of these changes made the Note go away in our case. I only found one voice claiming it could be an external reason which makes this message appear. Because we are actually running on a Cloud-Machine the appearance of this message could really be an effect of the Cloud and not caused by the Database or the Application.

We further know that our MariaDB Database has a more or less uniform workload over the day. Further it is a Master/Master (active/passive) set-up. So both nodes should see more or less the same write load at the same time.

But as our investigation clearly shows that the Note does not appear at the same time on both nodes. So I strongly assume it is a noisy-neighbour problem.

First we tried to find any trend or correlation between these 2 Master/Master Databases maas1 and maas2:

What we can see here is, that the message appeared on different days on maas1 and maas2. The database maas1 had a problem in the beginning of December and end of January. Database maas1 had much less problems in general but end of December there was a problem.

During night both instances seem to have less problems than during the day. And maas2 has more problems in the afternoon and evening.

If we look at the distribution per minute we can see that maas2 has some problems around xx:45 to xx:50 and maas1 more at xx:15.

Then we had a closer look at 28 January at about 12:00 to 15:00 on maas2:

We cannot see any anomalies which would explain a huge increase of dirty pages and and a page_cleaner stuck.

The only thing we could see at the specified time is that I/O latency significantly increased on server side. Because we did not cause more load and over-saturated the system it must be triggered externally:

This correlates quite well to the Notes we see in the MariaDB Error Log on maas2:

2020-01-28 12:45:27 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 5760ms. The settings might not be optimal. (flushed=101 and evicted=0, during the time.) 2020-01-28 12:46:00 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 6908ms. The settings might not be optimal. (flushed=4 and evicted=0, during the time.) 2020-01-28 12:46:32 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 5339ms. The settings might not be optimal. (flushed=17 and evicted=0, during the time.) 2020-01-28 12:47:36 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4379ms. The settings might not be optimal. (flushed=101 and evicted=0, during the time.) 2020-01-28 12:48:08 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 5053ms. The settings might not be optimal. (flushed=7 and evicted=0, during the time.) 2020-01-28 12:48:42 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 5760ms. The settings might not be optimal. (flushed=102 and evicted=0, during the time.) 2020-01-28 12:49:38 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4202ms. The settings might not be optimal. (flushed=100 and evicted=0, during the time.) 2020-01-28 12:57:28 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4615ms. The settings might not be optimal. (flushed=18 and evicted=0, during the time.) 2020-01-28 12:58:01 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 5593ms. The settings might not be optimal. (flushed=4 and evicted=0, during the time.) 2020-01-28 12:58:34 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 5442ms. The settings might not be optimal. (flushed=101 and evicted=0, during the time.) 2020-01-28 12:59:31 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4327ms. The settings might not be optimal. (flushed=101 and evicted=0, during the time.) 2020-01-28 13:00:05 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 5154ms. The settings might not be optimal. (flushed=82 and evicted=0, during the time.) 2020-01-28 13:08:01 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4321ms. The settings might not be optimal. (flushed=4 and evicted=0, during the time.) 2020-01-28 13:10:46 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 21384ms. The settings might not be optimal. (flushed=100 and evicted=0, during the time.) 2020-01-28 13:14:16 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4180ms. The settings might not be optimal. (flushed=20 and evicted=0, during the time.) 2020-01-28 13:14:49 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4935ms. The settings might not be optimal. (flushed=4 and evicted=0, during the time.) 2020-01-28 13:15:20 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4472ms. The settings might not be optimal. (flushed=25 and evicted=0, during the time.) 2020-01-28 13:15:47 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4358ms. The settings might not be optimal. (flushed=9 and evicted=0, during the time.) 2020-01-28 13:48:31 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 6212ms. The settings might not be optimal. (flushed=9 and evicted=0, during the time.) 2020-01-28 13:55:44 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4280ms. The settings might not be optimal. (flushed=101 and evicted=0, during the time.) 2020-01-28 13:59:43 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 5817ms. The settings might not be optimal. (flushed=4 and evicted=0, during the time.) 2020-01-28 14:00:16 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 5384ms. The settings might not be optimal. (flushed=100 and evicted=0, during the time.) 2020-01-28 14:00:52 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 9460ms. The settings might not be optimal. (flushed=5 and evicted=0, during the time.) 2020-01-28 14:01:25 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 7727ms. The settings might not be optimal. (flushed=103 and evicted=0, during the time.) 2020-01-28 14:01:57 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 7154ms. The settings might not be optimal. (flushed=5 and evicted=0, during the time.) 2020-01-28 14:02:29 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 7501ms. The settings might not be optimal. (flushed=5 and evicted=0, during the time.) 2020-01-28 14:03:00 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4322ms. The settings might not be optimal. (flushed=78 and evicted=0, during the time.) 2020-01-28 14:32:02 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4927ms. The settings might not be optimal. (flushed=4 and evicted=0, during the time.) 2020-01-28 14:32:34 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4506ms. The settings might not be optimal. (flushed=101 and evicted=0, during the time.)
Taxonomy upgrade extras: innodb page cleaner dirty pages migration flushing noisy neighbours