July 31, 2014

HandlerSocket on SSD

We all enjoyed Yoshinori announcement of HandlerSocket, the plugin to MySQL which open NOSQL way to access data stored in InnoDB. The published results are impressive, but I want to understand some, that’s why I run couple more experiments. In blog post Yoshinori used the case when all data fits into memory, and one of […]

Query Response time histogram – new feature in Percona Server

Recently we had couple posts dedicated to performance monitoring, i.e. Color code your performance numbers, Performance Optimization and Six Sigma, so you may understand we consider stability of performance numbers as one of important area for database management. That’s why we decided to add histogram of queries response times into Percona Server, and our software […]

RAID throughput on FusionIO

Along with maximal possible fsync/sec it is interesting how different software RAID modes affects throughput on FusionIO cards. In short conclusion, RAID10 modes really disappoint me, the detailed numbers to follow. To get numbers I run

test with 16KB page size, random read and writes, 1 and 16 threads, O_DIRECT mode. FusionIO cards are […]

fsyncs on software raid on FusionIO

As soon as we get couple FusionIO cards, there is question how to join them in single space for database. FusionIO does not provide any mirroring/stripping solutions and totally relies on OS tools there. So for Linux we have software RAID and LVM, I tried to followup on my post How many fsync / sec […]

Tuning for heavy writing workloads

For the my previous post, there was comment to suggest to test db_STRESS benchmark on XtraDB by Dimitri. And I tested and tuned for the benchmark. I will show you the tunings. It should be also tuning procedure for general heavy writing workloads. At first, <tuning peak performance>. The next, <tuning purge operation> to stabilize […]

Quick comparison of MyISAM, Infobright, and MonetDB

Recently I was doing a little work for a client who has MyISAM tables with many columns (the same one Peter wrote about recently). The client’s performance is suffering in part because of the number of columns, which is over 200. The queries are generally pretty simple (sums of columns), but they’re ad-hoc (can access […]

Just do the math!

One of the most typical reasons for performance and scalability problems I encounter is simply failing to do the math. And these are typically bad one because it often leads to implementing architectures which are not up for job they are intended to solve. Let me start with example to make it clear. Lets say […]

Should you move from MyISAM to Innodb ?

There is significant portion of customers which are still using MyISAM when they come to us, so one of the big questions is when it is feasible to move to Innodb and when staying on MyISAM is preferred ? I generally prefer to see Innodb as the main storage engine because it makes life much […]

MySQL File System Fragmentation Benchmarks

Few days ago I wrote about testing writing to many files and seeing how this affects sequential read performance. I was very interested to see how it shows itself with real tables so I’ve got the script and ran tests for MyISAM and Innodb tables on ext3 filesystem. Here is what I found:

How to estimate time it takes Innodb to Recover ?

Today seems to be Innodb day in our Blog, but well this is the question which pops ups quite frequently in Innodb talks and during consulting engagements. It is well known to get better performance you should normally set innodb_log_file_size large. We however usually recommend caution as it may significantly increase recovery time if Innodb […]