There are a couple of questions about the blog post on automatic thread configuration in RonDB. Rather than providing an extensive answer in the comment section I thought it was better to answer the questions in a separate blog. In addition I performed a set of microbenchmarks to verify my expectations.

The first question was the following:

ScyllaDB also does something similar with execution stages for better instruction cache. Is this similar to what you're implementing for instruction cache on separating the threads?

The second question is:

I don't really get the functional separation of threads. To execute a query, your data will now go through a pipeline of …

This blog introduces how RonDB handles automatic thread configuration. This blog is more technical and dives deeper under the surface of how RonDB operates. RonDB provides a configuration option, ThreadConfig, whereby the user can have full control over the assignment of threads to CPUs, how the CPU locking is to be performed and how the thread should be scheduled.

However for the absolute majority of users this is too advanced, thus the managed version of RonDB ensures that this thread configuration is based on best practices found over decades of testing. This means that every user of the managed version of RonDB will get access to a thread configuration that is optimised for their particular VM size.

In addition RonDB makes use of adaptive CPU spinning in a way that limits the power usage, but still provides very low latency in all database operations. …

MySQL NDB Cluster 8.0.20 new features 

This post is about changes in the implementation of NDB Cluster from MySQL NDB Cluster 8.0 through 8.0.20, as compared to earlier release series. We have included only those of MySQL NDB Cluster 8.0.20 new features which are really interesting and can directly influence / make an impact to performance, scalability and reliability:

• MySQL NDB Cluster  development is in parallel with the development of  MySQL Server going forward. What does that mean for MySQL customers globally NDB 8.0 is developed in, built from, and released with the MySQL 8.0 source code tree and numbering scheme for NDB Cluster 8.0 releases follows the scheme for MySQL 8.0 ( starting with version 8.0.13).
• As of NDB 8.0.18, The identifiers can use up to 64 bytes for databases and tables (the 63-byte limit on identifiers is removed ).
• Generated names for foreign keys …

Using numbers produced already with MySQL Cluster 7.6.10 we have
shown that NDB Cluster is the world's fastest Key-Value store using
the Yahoo Cloud Serving Benchmark (YCSB) Workload A.

Presentation at Slideshare.net.

We reached 1.4M operations using 2 Data Nodes and 2.8M operations
using a 4 Data Node setup. All this using a standard JDBC driver.
Obviously using a specialised ClusterJ client will improve performance
further. These benchmarks was executed by Bernd Ocklin.

The benchmark was executed in the Oracle Cloud. Each Data Node used
a Bare Metal Server using DenseIO which have 52 CPU cores with
8 NVMe drives.

The MySQL Servers and Benchmark clients was executed on Bare Metal
servers with 2 MySQL Server per server (1 MySQL Server per …

One thing that we announced in the GA release of MySQL Cluster 8.0 is
that we now support using 3 and 4 replicas. Actually the NDB software
was designed to support 1 through 4 replicas from the very get go in the
1990s. The reason it has not been supported is simply that we haven't
had any regular testing effort attached to it. Thus we haven't felt that
we can support such an important feature without having proper testing
of it.

What we did in the development of MySQL Cluster 8.0 is that we have
added a number of new configurations with both 3 replicas and with
4 replicas. These configurations will now be used in our daily testing
of NDB.

In the process of working on this we found some issues with arbitration
already in MySQL Cluster 7.6. This issue was fixed in 7.6 already.
So the way to decide how to handle a node failure in 7.6 and …

In this part we are going to analyze a bit more complex query than before.
This query is a 6-way join.

The query is:
SELECT
        supp_nation,
        cust_nation,
        l_year,
        SUM(volume) AS revenue
FROM
        (
                SELECT
                        n1.n_name AS supp_nation,
                        n2.n_name AS cust_nation,
                        extract(year FROM l_shipdate) as l_year,
                        l_extendedprice * (1 - l_discount) AS …

In this part we will discuss how NDB batch handling works. Query execution of
complex SQL queries means that more rows can be delivered than the receiver is
capable of receiving. This means that we need to create a data flow from the
producer where the data resides and the query executor in the MySQL Server.

The MySQL Server uses a record where the storage engine have to copy the result
row into the record. This means that the storage of batches of rows is taken
care of by the storage engine.

When NDB performs a range scan it will decide on the possible parallelism before
the scan is started. The NDB API have to allocate enough memory to ensure that
we have memory prepared to receive the rows as they arrive in a flow of result
rows from the data nodes. It is possible to set batch size of hundreds and even
thousands of rows for a query.

The …

First of all, I wish you a happy new year.
Many things happened last year, it was really exciting to be involved in the MySQL ecosystem.
I hope this enthusiasm will be increased this year, up to you !

To start the year, I propose the MySQL[plus] Awards 2011
It will only take 5 minutes to fill out these polls.
Answer with your heart first and then with your experience with some of these tools or services.

Polls will be closed January 31, so, vote now !
For “other” answers, please,  let me a comment with details.

Don’t hesitate to submit proposal for tools or services in the comments.
And, please, share these polls !

Note: There is a poll embedded within this post, …