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Displaying posts with tag: MyRocks (reset)
Testing MyRocks vs InnoDB Performance Using sysbench 1.x oltp_point_select.lua

It seems MyRocks is going to become a hot topic in April 2017. Previously (here and there) I tried to compare its performance and scalability vs InnoDB from MySQL 5.7.17 using test case from famous bug #68079. It's an interesting case that took a lot of efforts from Oracle to make InnoDB scale properly, and InnoDB (on my QuadCore box at least, others reported different results on other hardware in comments) still outperformed MyRocks. But maybe it's corner case that is not a big deal in general?

Earlier this month I decided to give MyRocks another chance and try it with "industry-standard" benchmarks, like those provided by

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MySQL Support Engineer's Chronicles, Issue #5

A lot of time passed since my previous post in this series. I was busy with work, participating in FOSDEM, blogging about profilers and sharing various lists of MySQL bugs. But I do not plan to stop writing about my usual weeks of doing support engineer's job. So, time for the next post in this series, based on my random notes taken during the week here and there.

This week started for me with checking recent MySQL bug reports (actually I do it every day). …

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More on MyRocks Performance for Bug #68079 Case

My previous post on MyRocks was intended to provide some background details for a couple of slides for my FOSDEM talk on profiling MySQL. The results and performance demonstrated by MyRocks vs InnoDB from MySQL 5.7.17 were not really important to show how perf helps to understand where the time was spent while executing of one specific query vs the other (with the same results, but different plan), but they still caused a lot of comments from people who care, so I decided to double check and clarify few more details.

First of all, it was …

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Profiling MyRocks with perf: Good Old Bug #68079 Use Case

Almost a year ago I've got really interested in MyRocks and built MySQL from Facebook that provides it from source. Since that time I build it from fresh sources few times per week (as I've described in that post) and once in a while try to work with it and study some details or use cases. Today I'd like to discuss one of them that I've recently studied with perf profiler.

This is not only because I am going to talk about applying profilers to all kinds and forks of MySQL at FOSDEM 2017 MySQL & Friends …

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Tab Sweep – MySQL ecosystem edition

Tab housekeeping but I also realise that people seem to have missed announcements, developments, etc. that have happened in the last couple of months (and boy have they been exciting). I think we definitely need something like the now-defunct MySQL Newsletter (and no, DB Weekly or NoSQL Weekly just don’t seem to cut it for me!).

MyRocks

During @scale (August 31), Yoshinori Matsunobu mentioned that MyRocks has been deployed in one region for 5% of its production workload at Facebook.

By October 4 at the …

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MySQL Support Engineer's Chronicles, Issue #4

This week I had to deal with some unusual problems. But let me start with Percona's xtrabackup, software that I consider a key component of many current production MySQL setups and use regularly. Recently new minor versions of XtraBackup were released, check the details on 2.4.5, for example. It made a step towards support of MariaDB 10.2, but it's still a long way to go, see this pull request #200.

My main problem with xtrabackup, though, is not with lack of support of MariaDB 10,2-specific features. Why should they care, after all... The problem is that old well known bugs and problems are not resolved, those that may affect all MySQL versions, forks and environments. Check  …

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Can RocksDB and InnoDB play along in MySQL?

My recent post about importing a big dataset from InnoDB into MyRocks has attracted quite a lot of attention (thank you Mark!) and also it has been pointed out that what I wrote about coexistence of MyRocks and InnoDB was incorrect.

In fact, I had been asking about it at Percona Live last month, but got a negative answer.... plus I had tried it at first but got a mysqld crash during crash recovery once, so since it was not important for my use case I went ahead and disabled InnoDB entirely.

But of course, as I have written previously, using both engines in the same server is something that I would really, really love to have, so I thought to give it a try with a very simple use case.

So I created the following two tables, each one with a different engine:

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MyRocks: migrating a large MySQL dataset from InnoDB to RocksDB to reduce footprint

I have been following Facebook's MyRocks project (and Mark Callaghan's blog) for a long time. The idea of an LSM based engine for MySQL is actually a great idea.
We all know that InnoDB sucks at INSERTs.  BTree in general sucks when it's about insertion speed, and the more rows you insert, the more it sucks at it. There are many blog posts on the web that shows the insert speed degradation in InnoDB when the amount of rows in the table grows. Things get much worse faster if your primary key is a random key, for example an UUID.
We hit this problem with our caching servers (yes, we do caching with MySQL!), and in order to be able to scale these servers up we moved since a couple years to the TokuDB engine with great success. TokuDB is based on fractal tree technology, and guarantees the same insert speed, no matter the number of rows you have in the table; furthermore, it …

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MyRocks has some strange performance issues for index scans

The details on this issue are here:
https://github.com/facebook/mysql-5.6/issues/369

This test is very simple. I loaded the SSB (star schema benchmark) data for scale factor 20 (12GB raw data), added indexes, and tried to count the rows in the table.

After loading data and creating indexes, the .rocksdb data directory is 17GB in size.

A full table scan "count(*)" query takes less than four minutes, sometimes reading over 1M rows per second, but when scanning the index to accomplish the same count, the database can only scan around 2000 rows per second. The four minute query would take an estimated 1000 minutes, a 250x difference.

I have eliminated the type of CRC32 function (SSE vs non-SSE) by forcing the hardware SSE function by patching the code.

There seem to be problems with any queries …

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MySQL Support Engineer's Chronicles, Issue #2

It's time to continue my new series that I've started 2 weeks ago. I'd like to start with a reminder that it's time to send your talks for "MySQL and Friends Devroom" at FOSDEM 2017 - the only MySQL-related event next year that I plan to attend in any case. It seems we have one more week to submit, but I've already filled in all the details for the "main" talk, "Understanding MyRocks locks and deadlocks". I'd like to apply my usual source code reading and gdb breakpoints approach in case if by the end of January, 2017 official documentation still misses important details. Official MySQL …

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