MariaDB-5.5.21-beta is the first MariaDB release featuring the new thread pool. Oracle offers a commercial thread pool plugin for MySQL Enterprise, but now MariaDB brings a thread pool implementation to the community!
If you are not familiar with the term, please read the Knowledge Base article about it.
The main design goal of the thread pool is to increase the scalability of the MariaDB server with many concurrent connections. In order to test and demonstrate this, I have run the sysbench OLTP RO benchmark with up to 4096 threads to compare the new pool-of-threads and the traditional thread-per-connection scheduler:
- sysbench multi table OLTP, readonly
- 16 tables, totaling 40 mio rows (~10G of data)
- 16G buffer pool – result is independent of disk performance
- mysqld bound to 16 cpu cores, sysbench to the other 8
Read/write OLTP benchmark results will be published as soon as they are available. …
Last weekend Vadim from Percona published his MariaDB 5.3.4 benchmark results. As the new benchmark guy at Monty Program I take this oportunity to add some more results of my own.
One question in the comments to Vadim was if it is fair to compare MariaDB-5.3 with MySQL-5.5. Or if this comparison should be done with MySQL-5.1. The answer is: it does not matter much. MySQL-5.5 and MySQL-5.1 show very similar results in the Sysbench OLTP benchmark.
So I created a Sysbench environment pretty much like Vadims and tested the following versions of the MySQL Server:
- MariaDB-5.3.4 – the Monty Program release candidate, both with XtraDB and the InnoDB plugin
- Percona-Server 5.1.61 because it is based on the same XtraDB version as MariaDB-5.3
- Percona-Server 5.5.20 – the current Percona flagship
- MySQL-5.5.20 – the current Oracle flagship
Indeed MariaDB-5.3.4 scales significantly worse than MySQL-5.5.20. …
In our upcoming MariaDB 5.3 release Monty optimized the internal string append code for performance. I tested his patch with a plain MariaDB 5.2 vs. a patched MariaDB 5.2 with sql-bench, which showed an overall performance gain around 3%.
The details of the patch Monty describes like this
Patch to optimize string append:
While examining a trace output from a mysql-test-run case, I noticed a
lot of reallocation calls. This was strange as MariaDB/MySQL was
designed to do so few malloc/realloc as possible. The system uses was
to first calculate how big buffer you would need and then allocate a
buffer big enough for most usage. …