To test restart times I am using the DBT2 test suite that
I developed based on DBT2 0.37 since 2006.
The following test setup is used:
DataMemory: 100 GByte (90 Gbyte in 7.5 and earlier)
IndexMemory: 10 GByte in 7.5 and earlier versions)
NoOfFragmentLogParts=8
NoOfFragmentLogFiles=50
FragmentLogFileSize=256M
MinDiskWriteSpeed=20M (two times the default)
MaxDiskWriteSpeed=40M (two times the default)
I load the database using LOAD DATA FROM INFILE with
precreated CSV files that contains the data for one
warehouse and table. This means that there are 8 CSV
files per warehouse. I load 600 warehouses into NDB.
This means a database size of around 60 GByte with
around 280 million rows.
Next I run the DBT2 from 2 MySQL servers using 16 threads
each for two minutes. This creates a load of almost
100k TPM.
…
Apart from bug fixes the 7.6.7 version of MySQL Cluster also
brings
a major improvement of restart times through adaptively
controlling
checkpoint speed.
Many DBMSs work hard on automating management of the database
nodes.
In NDB automated management was a design point from the very
first
version. This means that nodes crash and restart without
operator
assistance.
For the last years we have also worked on developing algorithms
that
require less configuration. This will greatly simplify the
configuration
of NDB Cluster.
In 7.6.7 we have made it much easier to configure handling of
checkpoints
(LCPs) and REDO logging.
In earlier versions of NDB the checkpoint speed has been
controlled by
two things. The first is based on the following configuration
variables:
MinDiskWriteSpeed: This is the minimum disk …
MySQL NDB Cluster has great support for online (inplace) schema
changes, but it is still sometimes necessary to perform an
offline (copying) ALTER TABLE
. These are relatively
expensive to make as the entire table is copied into a new table
which eventually replace the old table.
One example where a copying ALTER TABLE
is required
is when upgrading from MySQL NDB Cluster 7.2 or earlier to MySQL
NDB Cluster 7.3 or later. The format used for temporal columns
changed between these version (corresponding to MySQL Server 5.5
to 5.6). In order to take advantage of the new temporal format, a
table rebuild is required.
Note: Support for the old temporal format has been removed in MySQL 8.0. So, you must …
[Read more]In Percona Monitoring and Management (PMM) 1.13 we have adopted Prometheus 2, and with this comes a dramatic improvement in resource usage, along with performance improvements!
What does it mean for you? This means you can have a significantly larger number of servers and database instances monitored by the same PMM installation. Or you can reduce the instance size you use to monitor your environment and save some money.
Let’s look at some stats!
CPU Usage
We can see an approximate 5x and 8x reduction of CPU usage on these two PMM Servers. Depending on the workload, we see CPU usage reductions to range between 3x and 10x.
Disk Writes
There is also less disk write bandwidth required:
On this instance, the bandwidth reduction is “just” 1.5x times. …
[Read more]In this blog post, we’ll discuss how to set a replication from MySQL 8.0 to MySQL 5.7. There are some situations that having this configuration might help. For example, in the case of a MySQL upgrade, it can be useful to have a master that is using a newer version of MySQL to an older version slave as a rollback plan. Another example is in the case of upgrading a master x master replication topology.
Officially, replication is only supported between consecutive major MySQL versions, and only from a lower version master to a higher version slave. Here is an example of a supported scenario:
5.7 master –> 8.0 slave
while the opposite is not supported:
8.0 master –> 5.7 slave
In this blog post, I’ll walk through how to overcome the …
[Read more]In this blog post, we talk about how to run applications across multiple clouds (i.e. AWS, Google Cloud, Microsoft Azure) using Continuent Clustering. You want your business-critical applications to withstand node, datacenter, availability-zone or regional failures. For SaaS apps, you also want to bring data close to your application users for faster response times and a better user experience. With cross-cloud capability, Continuent also helps avoid lock-in to any particular cloud provider.
The key to success for the database layer is to be available and respond rapidly.
From both a business and operational perspective, spreading the application across cloud environments from different vendors provides significant protection against vendor-specific outages and vendor lock-in. Running on multiple platforms provides greater …
[Read more]Please join Percona’s Architect, Tibi Köröcz as he presents Utilizing ProxySQL for Connection Pooling in PHP on Tuesday August 14, 2018, at 8:00 am PDT (UTC-7) / 11:00 am EDT (UTC-4).
ProxySQL is a very powerful tool, with extended capabilities. This presentation will demonstrate how to use ProxySQL to gain functionality (seamless database backend switch) and correct problems (applications missing connection pooling).
The presentation will be a real-life study on how we use ProxySQL
for connection pooling, database failover and load balancing the
communication between our (third party) PHP-application and our
master-master MySQL-cluster.
Also, we will …
Recently one of our customers wanted us to benchmark InnoDB, TokuDB and RocksDB on Intel(R) Xeon(R) Gold 6140 CPU (with 72 CPUs), nvme SSD (7 TB) and 530 GB RAM for performance. We have used Ubuntu xenial 16.04.4, Percona Server 5.7 (included storage engines- InnoDB/XtraDB, TokuDB and RocksDB) and Sysbench 1.0.15 with custom Lua scripts for this exercise, This benchmarking exercise included bulk INSERTS, WRITES, READS and READS-WRITES. We have tried our best to capture maximum information about the hardware infrastructure and copied / shared scripts we have used for benchmarking. This is not a paid / sponsored benchmarking effort by any of the software or hardware vendors, We will remain forever an vendor neutral and independent web-scale database infrastructure operations company with core expertise in performance, scalability, high availability and database reliability engineering. This benchmarking is …
[Read more]
A good news for all PHP CMS users like Drupal and Joomla!, PHP 7.2.8 (available on Remi’s repo for those using rpms) supports the
new MySQL 8.0 default authentication plugin
‘caching_sha2_password
‘ !
So, I’ve installed PHP 7.2.8:
And I’ve my user (here joomla) uses the …
[Read more]As other CMS using MySQL and PHP, Joomla! is not yet 100% ready to work with MySQL 8.0 out of the box.
I’ve been contacted by Brian Teeman to give my opinion and some tips… so here is the blog post
@lefred If you could offer some advice on this #joomla #mysql 8 issue it would be appreciated https://t.co/FS37GVunEO
— ((( Brian Teeman ))) (@brianteeman) …
[Read more]