MySQL crash-safe replication is an old feature (~4 years as of MySQL 5.6), but it’s not consistently understood or applied. The MySQL manual on the topic, 16.3.2 Handling an Unexpected Halt of a Replication Slave, is correct and authoritative, but unless you grok MySQL replication that page doesn’t make it obvious why crash-safe replication works. Other blog posts explain why, but sometimes add other considerations, making it unclear which settings are necessary and sufficient.
Jan
24
2018
Jan
24
2018
MySQL crash-safe replication is an old feature (~4 years as of MySQL 5.6), but it’s not consistently understood or applied. The MySQL manual on the topic, 16.3.2 Handling an Unexpected Halt of a Replication Slave, is correct and authoritative, but unless you grok MySQL replication that page doesn’t make it obvious why crash-safe replication works. Other blog posts explain why, but sometimes add other considerations, making it unclear which settings are necessary and sufficient.
Jan
24
2018
MySQL crash-safe replication is an old feature (~4 years as of MySQL 5.6), but it’s not consistently understood or applied. The MySQL manual on the topic, 16.3.2 Handling an Unexpected Halt of a Replication Slave, is correct and authoritative, but unless you grok MySQL replication that page doesn’t make it obvious why crash-safe replication works. Other blog posts explain why, but sometimes add other considerations, making it unclear which settings are necessary and sufficient. The aim of this blog post is total enlightenment, a full crash-safe-spiritual awakening. Light the censers and let us begin at the beginning…
Jan
24
2018
MySQL crash-safe replication is an old feature (~4 years as of MySQL 5.6), but it’s not consistently understood or applied. The MySQL manual on the topic, 16.3.2 Handling an Unexpected Halt of a Replication Slave, is correct and authoritative, but unless you grok MySQL replication that page doesn’t make it obvious why crash-safe replication works. Other blog posts explain why, but sometimes add other considerations, making it unclear which settings are necessary and sufficient.
Jan
24
2018
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]
Jan
23
2018
In this blog post, we’ll look at the performance hit from the Spectre bug fix on Ubuntu.
Recently we measured the performance penalty from the Meltdown fix on Ubuntu servers. It turned out to be negligible.
Today, Ubuntu made a Spectre bug fix on Ubuntu available, shipped in kernel 4.4.0-112. As with the Meltdown fix, we measured the effect of this update. Unfortunately, we observed a major performance penalty on MySQL workloads with this new kernel.
Our benchmark used the following:
System:
- CPU:
- 2 x Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz (Codename Haswell)
- /proc/cpuinfo has 48 …
Jan
22
2018
Join Percona’s Chief Evangelist, Colin Charles as he presents Differences Between MariaDB and MySQL on Wednesday, January 24, 2018, at 7:00 am PST (UTC -8) / 10:00 am EST (UTC -5).
Tags: MariaDB, MySQL, Percona Server for MySQL,
DBA, SysAdmin, DevOps
Experience Level: Novice
MariaDB and MySQL. Are they syntactically similar? Where do these two query languages differ? Why would I use one over the other?
MariaDB is on the path of gradually diverging from MySQL. One obvious example is the internal data …
[Read more]
Jan
22
2018
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]
Jan
22
2018
In this blog post, I’d like to show some relationships of “Group Replication” and “InnoDB Cluster“. My hope is that I will be able to draw meaningful correlations and attempt to simplify our way of thinking about these setups. The MySQL development team released the first GA release of Group Replication in MySQL 5.7.17, which turns… Read More »
Jan
22
2018
Although it feels like it was only yesterday that Oracle released version 5.7 of their acclaimed MySQL Community Server, version 8 is already available as a development milestone release (DMR). No, you didn’t sleep through a bunch of releases; MySQL is jumping several versions in its numbering due to 6.0 being dropped and 7.0 being reserved for the clustering version of MySQL. This new version boasts numerous changes (and bug fixes), one of the most exciting of which are replication enhancements. This blog will provide an overview of the new replication enhancements, including new replication timestamps, additional information reported by performance schema tables, and how replication delay has been reduced by updating the relationship between replication threads to make them more efficient.
New Replication Timestamps
The most common task when managing a …
[Read more]