open life blog
The thing I really like with open source is the feeling you get when people just show up from nowhere and do great things to some code you originally wrote. Thanks to this miracle, I can now also present to you version 0.2 of the Drizzle JSON HTTP support, featuring a "pure JSON key-value API" in addition to the original "SQL over HTTP" API in 0.1 version. Let's recap what happened:
- At Drizzle Day 2011, I proposed that Drizzle should make available a JSON NoSQL interface. Stewart took the bait and published json_server 0.1 a week later. This API still uses SQL, it's just that the client protocol is HTTP and JSON, into which the SQL is embedded. So I suppose it's not as sexy as real NoSQL, but pretty cool nevertheless.
- At the end of last Summer I had a lot of dead time so I started playing with Stewart's code to see what I could do. I added a new API in addition to Stewart's SQL-over-HTTP API that supports key-value operations in pure JSON, similar to what you see in CouchDB, MongoDB or Metabase. I got it working quite well, however, I never implemented a DELETE command, because I then drifted off to more important tasks, such as revamping the Drizzle version numbering and bringing DEB and RPM packaging up to date.
- Last week a new but very promising Drizzle hacker called Mohit came by, looking for things he could do. He had already fixed a simple low-hanging-bug and wanted something more. Since he was interested in the JSON API, I asked if he wants to finish the missing piece. With my helpful advice of "there is no documentation but if you look at the demo GUI you'll probably figure it out, then just look at the code for POST and implement DELETE instead". I was afraid that wasn't really helpful, but I was busy that day. No problem, the next day Mohit had pushed working DELETE implementation. The day after that he implemented the final missing piece, a CREATE TABLE functionality. I was both impressed and excited.
There will be a book signing opportunity at the MySQL User Conference, more precisely at the Expo Hall Community Reception on Wednesday evening. You will be able to meet and talk to authors of great MySQL related books. ...and myself.
Oh boy, I'm starting to feel the stress of having to prepare a little bit of this and a little bit of that for the upcoming MySQL User Conference (Santa Clara, April 10 to 13). But I wanted to also jump on this meme and list a few sessions I definitively want to attend:
I'm speaking, so I suppose I need to attend:
- How to evaluate which MySQL High Availability solution best suits you. This 3 hour tutorial I'm co-presenting with Ben Mildren, a former Nokia collague who now works with Pythian.
Alex Yurchenko finally posted results on a benchmark he has planned to do for a long time: Galera vs NDB cloud shootout.
Their blog requires registration to comment, so I'll post my comment here instead:
Sysbench can do the loadbalancing itself, so there is no need for external loadbalancer. Just add a comma separated list of master MySQL nodes to --mysql-host. This is similar to what the JDBC and PHP drivers can do too, and it is my favorite architecture. Why introduce extra layers of stuff that you don't need and that doesn't bring any additional value?
Earlier today I posted a Drizzle white paper we've been working on: Drizzle and IPv6.
With apologies to Planet MySQL readers. This post is about MySQL, but it is not technical, and probably not at all interesting to many of my usual readers. But it didn't fit in a tweet...
The Open Invention Network announced that its members have agreed to broaden the scope of the "protection" that it offers its members against software patent attacks against "The Linux System". Simon Phipps, a former Sun collague whom I follow on Twitter, covered the OIN in a very informative InfoWorld piece:
Actually, I had created this simple Drupal input filter for this site, openlife.cc, that I created when publising the English translation of my book Open Life: The Philosophy of Open Source. I wanted to have a simple way to have footnotes within HTML, without having to number them and format them myself. (Same functionality that is common for any word processor.) Drupal's input filter framework made it very simple to add an fn tag. You can see it at work if you read the online version of my book from the openlife.cc web site.
Yep. I see this too at work. InnoDB is in my opinion really good at handling concurrent workloads. So good I was surprised when I eventually found a project that was having locking issues. SHOW ENGINE INNODB STATUS showed queries had been waiting for hours on some locks they would never get. Yeah, it's a large and busy database, but it took me by surprise nevertheless.
It turns out, while InnoDB handles concurrent UPDATEs very efficiently, a combination of transactions that DELETE and INSERT rows - even just in the same general area of a table - will make the transactions wait for each other. Hence a workload that does a lot of inserts and deletes may get you into trouble. The solution is to change to READ COMMITTED or even READ UNCOMMITTED mode.