Search Results for: concurrency bug

InnoDB scalability issues due to tables without primary keys

Each day there is probably work done to improve performance of the InnoDB storage engine and remove bottlenecks and scalability issues. Hence there was another one I wanted to highlight: Scalability issues due to tables without primary keys This scalability issue is caused by the usage of tables without primary keys. This issue typically shows […]

Percona Server 5.6.13-61.0 first GA release is now available

Percona is glad to announce the first GA (Generally Available) release of Percona Server 5.6.13-61.0 on October 7th, 2013 (Downloads are available here and from the Percona Software Repositories. Based on MySQL 5.6.13, including all the bug fixes in it, Percona Server 5.6.13-61.0 is the first GA release in the Percona Server 5.6 series. All […]

Percona Server 5.5.32-31.0 now available

Percona is glad to announce the release of Percona Server 5.5.32-31.0 on July 2nd, 2013 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.5.32, including all the bug fixes in it, Percona Server 5.5.32-31.0 is now the current stable release in the 5.5 series. All of Percona‘s software is open-source and free, all the details of the release […]

Percona Server 5.6.11-60.3 first Release Candidate now available

Percona is glad to announce the first Release Candidate release of Percona Server 5.6.11-60.3 on June 3rd, 2013 (Downloads are available here and from the Percona Software Repositories). Based on MySQL 5.6.11, including all the bug fixes in it, Percona Server 5.6.11-60.3 is the first RC release in the Percona Server 5.6 series. All of […]

Percona XtraDB Cluster 5.5.30-23.7.4 for MySQL now available

Percona is glad to announce the release of Percona XtraDB Cluster 5.5.30-23.7.4 for MySQL on April 17, 2013. Binaries are available from the downloads area or from our software repositories. New Features: Percona XtraDB Cluster has implemented initial implementation of weighted quorum. Weight for node can be assigned via pc.weight option in the wsrep_provider_options variable. […]

trx descriptors: MySQL performance improvements in Percona Server 5.5.30-30.2

One major problem in terms of MySQL performance that still stands in the way of InnoDB scalability is the trx_list scan on consistent read view creation. It was originally reported as a part of MySQL bug #49169 and can be described as follows. Whenever a connection wants to create a consistent read, it has to […]

kernel_mutex problem cont. Or triple your throughput

This is to follow up my previous post with kernel_mutex problem. First, I may have an explanation why the performance degrades to significantly and why innodb_sync_spin_loops may fix it. Second, if that is correct ( or not, but we can try anyway), than playing with innodb_thread_concurrency also may help. So I ran some benchmarks with […]

Avoiding auto-increment holes on InnoDB with INSERT IGNORE

Are you using InnoDB tables on MySQL version 5.1.22 or newer? If so, you probably have gaps in your auto-increment columns. A simple INSERT IGNORE query creates gaps for every ignored insert, but this is undocumented behaviour. This documentation bug is already submitted. Firstly, we will start with a simple question. Why do we have […]