Showing entries 3541 to 3550 of 22620
« 10 Newer Entries | 10 Older Entries »
Displaying posts with tag: MySQL (reset)
Does the Version Number Matter?

Yes, it does! In this blog post, I am going to share my recent experiences with ProxySQL and how important the database software version number can be.

Migration

I was working on a migration to Percona XtraDB Cluster (PXC) with ProxySQL, fortunately on a staging environment first so we could catch any issues (like this one).

We installed Percona XtraDB Cluster and ProxySQL on the staging environment and repointed the staging application to ProxySQL. At first, everything looked great. We were able to do some application tests and everything looked good. I advised the customer to do more testing to make sure everything works well. …

[Read more]
Conference review Percona Live Santa Clara 2018

Percona Live Santa Clara, an annual event where open source database users, developers and enthusiasts come together, was held in April at the Santa-Clara convention centre. Pythian was well represented once more with no less than five presentations and a total of nine attendees.

This year the conference was condensed to two days of breakout sessions and one day of tutorials. Though it was shorter in length, the organizers broadened their horizons by including not only MySQL and MongoDB tracks, but this year they even put together a full PostgreSQL track. Moving from MySQL only to multiple technologies, inspired this year’s tagline: polyglot persistence conference. The increase in number of sessions allowed for a lot more options, but the condensed schedule made it much harder to choose which sessions to attend!

My observation from last year’s …

[Read more]
MySQL 8 invisible indexes

MySQL 8 supports invisible indexes, This allows you to on-demand enable/disable indexes from being used by MySQL optimizer. Now please don’t get confused with “disabled indexes“, “invisible indexes are not disabled indexes, MYISAM supports disabled indexes, ” , The disabled indexes halt maintenance of an index. Invisible indexes are a new feature in MySQL 8.0 , which mark an index unavailable for use by the optimizer. That means, Index will still be maintained and keep up-to-date as data is modified, but no queries will be permitted to make use of the index (even if the query uses a FORCE INDEX hint) .

Why we really love invisible indexes in MySQL 8.0?

  • You want to make only one query to use that index, In this case “invisible index” is a great option
  • On-demand indexing, You will have index (up-to-date with data) but you can make it visible or …
[Read more]
When “log sequence number X is in the future” is a non-issue

While seeding a bunch of new slaves for an infrastructure (and after I had successfully seeded and started replication on several, and I can verify that the database is consistent), one of my fellow DBAs checks the mysql error log and says “INNODB CORRUPTION!!”.

All of my servers were spewing these errors.

2018-05-09T10:29:10.420943-05:00 0 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to http://dev.mysql.com/doc/refman/5.7/en/forcing-innodb-recovery.html for information about forcing recovery.

2018-05-09T10:29:10.421717-05:00 0 [ERROR] InnoDB: Page [page id: space=XXXX, page number=XXXXXXXX] log sequence number XXXXXXXXXXX is in the future! Current system log sequence number XXXXXXXXX.

But — No.  I do not have InnoDB corruption in this case.  I discovered a brand new gripe with MySQL & InnoDB.  This is not a ‘bug’ but more …

[Read more]
MySQL 8.0: InnoDB now supports Instant ADD COLUMN

Instant DDL has been one of the most requested InnoDB features for a very long time. With ever larger and rapidly growing datasets the ability to do DDL instantly is a must have feature in any web scale database.  Developers constantly need to add new columns to meet the constantly changing business requirements.  …

Deploying PMM on Linode: Your $5-Per-Month Monitoring Solution

In this blog, I will show you how to install PMM on Linode as a low-cost database monitoring solution.

Many of my friends use Linode to run their personal sites, as well as small projects. While Linode is no match for Big Cloud providers in features, it is really wonderful when it comes to cost and simplicity: a Linode “nanode” instance offers 1GB of memory, 1 core, 20GB of storage and 1TB of traffic for just $5 a month.

A single Linode instance is powerful enough to use with Percona Monitoring and Management (PMM) to monitor several systems, so I use Linode a lot when I want to demonstrate PMM deployment through Docker, rather than …

[Read more]
MySQL Performance : 8.0 RW & Binlog impact

In the previous article I've intentionally skipped the topic related to Binlog impact on MySQL 8.0 Performance, because it's not a short story, nor a simple one..
In fact, for most of people Binlog in MySQL is generally representing and additional overhead, and historically it was true. Since MySQL 5.6 there is Binlog Group Commit (BGC) feature available, and it was rather doing well, decreasing the gap between "binlog=OFF" and "binlog=ON sync_bin=1". However, storage vendors are making flash drives more and more better from year to year.. And when we delivered MySQL 5.7 the scope of Binlog impact moved with code and flash improvements -- the main impact was no more coming from the I/O operations …

[Read more]
MySQL Performance : 8.0 and Sysbench OLTP_RW / Update-NoKEY

This post is following previously published OLTP_RO results for MySQL 8.0 ( latin1 and utf8mb4 charsets), and now is focusing on Sysbench RW workloads, particularly "mixed" OLTP_RW and Update-NoKey :

  • OLTP_RW : while this workload has writes, it's mainly driven by reads (OLTP_RO + 2 updates + delete + insert)
  • Update-NoKey : aggressively bombarding UPDATE queries (but with no changes on indexed columns)


The same 2S Skylake server was used as in previous tests :
Server configuration :

  • OS : Oracle Linux 7.4
  • CPU : 48cores-HT Intel Skylake 2.7Ghz (2CPU sockets (2S), Intel(R) Xeon(R) Platinum 8168 CPU)
[Read more]
MySQL InnoDB Cluster Tutorial Videos

We just published a series of 4 video tutorials about our native, full-stack, out-of-the-box and easy to use High Availability and Scaling solution for MySQL: InnoDB Cluster!

If you want to see the new MySQL Shell 8.0 in action to create a MySQL InnoDB Cluster and try it out yourself, just take a look!…

How InnoDB confirms maximum transaction durability in MySQL 8 ?

In transaction processing systems we have to guarantee the transaction committed will be durable permanently. For example, In an online commerce platform, The completed transaction will remain safe even if the system crashes. This can be achieved by flushing the transactional log records to non-volatile storage devices before acknowledging the commit. MySQL guarantees maximum durability of transaction by optimally setting following system variables :

innodb_doublewrite (enabled by default) 

InnoDB stores all data twice, first to doublewrite buffer (storage area in system tablespace to write pages that are flushed from InnoDB buffer pool, before written in data file). If ever operating system / storage / mysqld process crash during the middle of page write, InnoDB can still find a durable copy of the page from doublewrite buffer for recovery. Though data is written twice,  the doublewrite buffer …

[Read more]
Showing entries 3541 to 3550 of 22620
« 10 Newer Entries | 10 Older Entries »