Generally, when I'm analyzing MySQL Performance on Linux with "localhost" test workloads, I'm configuring client connections to use IP port (loopback) to connect to MySQL Server (and not UNIX socket) -- this is still at least involving IP stack in the game, and if something is going odd on IP, we can be aware ahead about. And indeed, it already helped several times to discover such kind of problems even without network links between client/server (like this one, etc.). However, in the past we also observed a pretty significant difference in QPS results when IP port was used comparing to UNIX socket (communications via UNIX socket were going near 15% faster).. Over a time with newer OL kernel releases this gap became smaller and smaller. But in all such …
[Read more]While updating my class image to Fedora 27, I noticed that it installed the Akonadi Server. The documentation on the Akonadi server lacked some straightforward documentation. It also offered a bundled set of software that limited how to approach MySQL development.
So, I removed all those packages with the following syntax:
dnf remove `rpm -qa | grep akonadi`
After removing those Akonadi packages, I installed the MySQL Community Edition from the Fedora repo with this syntax:
yum install -y community-mysql*
Having installed MySQL Community Edition, I started the service with this command:
sudo service mysql start
Then, I ran the mysql_secure_installation script to secure the installation:
mysql_secure_installation
The script set the root user’s password, remove the
anonymous user, disallow remote root login, and …
We have been told many times that modifying live database should
be done with extreme care, we should always make a backup before
doing something big to the database. However, there are countless
stories on the Internet about losing data due to various reason,
one of them is forgetting to create a backup (Gitlab is an
example: https://about.gitlab.com/2017/02/01/gitlab-dot-com-database-incident/).
I was facing the same issue when upgrading MySQL server to a new
version. Luckily I was able to restore most of the data but it
was still a very good lesson for me. One of lesson I learned is
how we could restore the data from the *.ibd and
*.frm file.
The database I worked with had many tables. There were about 5 of them using MyISAM engine while others were using InnoDB engine. I was asked to upgrade …
[Read more]Continuent is very pleased and excited to announce that the new Tungsten Clustering 6.0 and Tungsten Replicator 6.0 are now available for download by our customers. The 6.0 release is the culmination of over a years work within our clustering product in order to improve the functionality and manageability of what we now call our ‘Multimaster Clustering’ solution. This is the replacement for what we called the multi-site, multi-master (MSMM) clustering functionality in earlier releases. The multimaster clustering allows for multiple clusters, in multiple locations, to be linked together into a single composite cluster. Because it’s a composite cluster, you gain all of the functionality that’s already available in a cluster, such as:
- High availability
- Failover
- Automated recovery
- Read-write split
- Maintenance without downtime
But it’s now applied to the …
[Read more]In the following we show how InnoDB cluster can be deployed in a container context. In the official documentation (Introducing InnoDB Cluster), InnoDB is described as: MySQL InnoDB cluster provides a complete high availability solution for MySQL. MySQL Shell includes AdminAPI which enables you to easily configure and administer a group of at least three […]
In this blog post, We will be explaining about the timeouts in SST on systemd implementation which we faced recently in Percona XtraDB Cluster during our Consulting with a client. State Snapshot Transfers (SST) refers to complete data sync from one of the nodes from the cluster to the joining node.
SST will happen for one or more reasons listed below.
- Initial sync to join a node to cluster.
- Node is out of cluster and lost its ability to join back due to data corruption or inconsistencies and also when the node went far behind the node, …
Recently, I was working with one of our customer and this is what their requirement as they want to automate this process for converting galera node to async slave and make async slave to galera node without shutting down any server. ———- Here are the steps for how to do that. I assumes that you already have working 3 nodes galera cluster if not, then for the testing purpose you can create it from my previous post. setup-three-nodes-mariadb-galera-cluster-on-single-server-with-mysql-sandbox ———- Btw, there is no matter how many nodes you have. Now, create one test1 table and add 3 records in galera cluster.
MariaDB [nil]> select * from test1; +------+-----------+ | id | name | +------+-----------+ | 1 | nilnandan | | 2 | joshi | | 3 | niljoshi | +------+-----------+ …[Read more]
As Mydbops we are implementing Load Balancer using Maxscale or ProxySQL ( Our presentation ) for lot our client, but these load balancers will become a SPOF (Single Point of failure) . We have tried to explore services like HAProxy, Nginx, and Keepalived etc. Except Keepalived, all the services need to run on the standalone instance and did not satisfy our exact need.
Keepalived does not requires any standalone instance, it can be deployed and configured with a minimal effort and provide the HA Solutions to the DB Infra. This approach not only fits for our DB setup, we can implement same …
[Read more]Once upon a time CPU utilization was quite a useful metric. Following are the output of several tools that provide CPU utilization metrics:
top
top reports a load of 1.66.
Is this correct? No. The correct load number is probably closer to 2.4.
# top -b -n 1| head -20 top - 11:27:45 up 151 days, 1:55, 7 users, load average: 1.66, 1.84, 1.88 Tasks: 389 total, 3 running, 386 sleeping, 0 stopped, 0 zombie Cpu(s): 0.7%us, 20.6%sy, 1.2%ni, 77.3%id, 0.1%wa, 0.0%hi, 0.1%si, 0.0%st Mem: 32639636k total, 32206476k used, 433160k free, 235732k buffers Swap: 16359420k total, 10285664k used, 6073756k free, 2354840k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 16702 root 20 0 8274m 5.0g 5.0g S 85.1 16.1 59164:55 VirtualBox 4657 root 20 0 9.8g 5.2g 5.1g S 45.5 16.6 26518:13 VirtualBox 6239 root 20 0 9.8g 5.1g 5.1g S 39.6 16.5 31200:52 VirtualBox 27070 root …[Read more]
Donkey system is a fully automatic MySQL database change
system.
It gives a great help both to the release of the business and the
company’s automated operation and maintenance.