The Life and Times of Michael Shadle

With the whole MySQL/Oracle issue going on, I find myself looking into the future and how I see it. As far as I'm concerned, MySQL will start to lose it's popularity as the landscape changes. As far as I am concerned, there will be two key players in the MySQL replacement market, those being Drizzle and MariaDB.

I am not just saying Drizzle just because I help out with the project in various ways, however, that should be a good sign that I believe in it if I am willing to put any effort into it. With people behind it like Brian Aker, Eric Day, Monty Taylor, Stewart Smith, Jay Pipes, you've got a coding powerhouse that could solve the cancer issue if it was up to software development to fix it. These guys work around the clock and have been refactoring and re-examining everything inside of MySQL. What's going to be left ideally is a superfast microkernel that supports plugins for everything - leveraging the best options out there for replication, messaging, storage engines, etc. Growing apart from the monolithic huge distribution model that MySQL currently follows.

The second key player is MariaDB. Another fork off of MySQL, led by Monty Widenius himself and with other MySQL key players behind it, there is no doubt it will continue Monty's legacy as being able to spin success out of a tiny little open source product. I believe it will stay more traditional in-line with MySQL, but will provide more advanced functionality and scalability as it is developed further.

I won't get into other options like PostgreSQL as I don't follow the rest of the community there much.

Also, we'll see more NoSQL (did we ever bottom out on a better term for that?) options. CouchDB and MongoDB (both of which from a 50,000 foot view look identical from a usage model) and options like Cassandra will also become important and your data needs will become the decision maker for going with a SQL or a NoSQL database. Both of which offer advantages. However, I see Drizzle as making huge strides in leveling the playing field (or attempting to) with it's replication work to make it as scalable as NoSQL databases seem to be with their ability to scale out and replicate changes easily (which to me are their main selling point right now...)

Anyway, this is from a user perspective, not a developer perspective, and from what I've seen from #drizzle on freenode, a few SQL and open source conferences, blog talk and my own gut feelings.

I should make a note that I still use MySQL and will probably continue for some time. Neither Drizzle nor MariaDB are production-friendly yet. However, I believe 2010 should see the first "production capable" release of Drizzle (not sure of MariaDB.)

It is an exciting time though as we're starting to be presented with more options by the day, in fact there are so many various NoSQL databases now, key/value stores, and even a few more SQL databases that it's too hard to keep track of them anymore. There's a lot of code being written and with this whole Oracle possibly inheriting MySQL depending on the EU's judgement, it could ultimately help usher in some of these smaller projects into the spotlight quicker depending on what Oracle does with MySQL...

Thanks to Monty, I've learned something that will save me a lot of headache in the future. I had a bunch of random scripts I wrote myself to try to keep things in sync, turns out most of the work is already all done for me.

On the source host you want to clone:

dpkg --get-selections > file

On the destination host:

dpkg --set-selections < file
apt-get dselect-upgrade

Now your machines should be identical, package-wise.

Typically, updates on the open source packages work without a hitch. However, my upgrade last weekend on my servers from Ubuntu Hardy to Intrepid wound up creating a couple major headaches, and at the same time, I noticed a handful of other snafoos happening to open source packages I use daily.

This wound up in server instability, client annoyance, and 20-30 hours solid of trial-and-error compiling, testing, debugging, etc. Even right now, if I forget to hold back the libgpac-dev package from being updated, all videos being converted lose their sound due to MP4Box crashing.

• NFS broke - on only *one* of six identically configured machines. For the time being, running 2.6.24-16-server has been my only workaround. Trying all three kernels in the Ubuntu repository (2.6.27-7-server, 2.6.27-10-server, and 2.6.28-2-server) all suffered from this issue. Sadly, could not provide much debugging or relevant information to anyone, the machine is in production and I've got nothing in logs to go off of. Five of the six servers are running the newer kernels without an issue, which is what is odd.
• ffmpeg broke resampling of a common audio type - oddly enough, this can be fixed by issuing two separate ffmpeg commands. There is a patch on the mailing list, but still not implemented into SVN.
• MP4Box no longer works on Ubuntu, due to an issue with libgpac-dev - still no fix available, have to force using an older libgpac-dev version.
• nginx releases 0.7.25, a new feature in 0.7.25 had a bug, 0.7.26 comes out - luckily, Igor's fix was quick and effective, before I even had a chance to run 0.7.25.
• PHP 5.2.7 comes out with a somewhat critical "security" issue (magic quotes was broken), has to release 5.2.8 shortly after - I have to wait for Suhosin and PHP-FPM patches before I can adopt a new version of PHP; otherwise, this may have caused some headache for me.
• MySQL 5.1 comes out with crashing bugs - I stick to using MySQL from the standard Ubuntu repositories, which usually has a decent lag while seeking "stability" - thank God for that.

I dislike wikis. At work we were using them. Now we're changing from wikis to an article management system. The idea on paper sounded great, but I'm realizing the pitfalls about the implementation.

There are some traits that wikis have that I like. There's also plenty of bad traits. Also, I'm thinking of MediaWiki when I say this stuff.

Pros:

• Interlinking and updating
• Anyone can edit pages by design
• Templates and categorization can be done by anyone, inline
• Every page has a discussion option

Cons:

• Lots of overhead
• Semi-proprietary syntax (= makes h1, == makes h2, * makes one level lists, ** makes it a two level list, etc.)
• Inconsistent syntax - some HTML works, some bbcode-ish wiki stuff works, some __HEREDOC__ stuff works
• Forces everything to be CamelCase
• No attachments per page, only global
• By default, wikis have no page-level security, since their mantra is "anyone can edit"

So now that I've said that - I have to say that the ideal approach would be to take the existing CMS approach but add in a few wiki features. Specifically the interlinking. We already have a comment feature on every page. Attachment management is per-page too.

Late night half dazed thoughts:

Link syntax couldn't be something like foo:bar - since javascript:foo would conflict. Perhaps something like [foo:bar] would be a good idea? For links to file attachments, [file:fileID] or [article:slug-title]. This would make life simpler for tracking what files are orphans, can display information about the file in-line in the documents (file type, size, etc.)

One thing most places forget to mention, at least clearly, is the need to update the LU tools before you run the upgrade.

This assumes you have the DVD .iso already on the system, and you are mounting it to a directory (in this example, /export/loop)

First update the LU tools off the new disc. This process wasn't really included in a lot of blogs I read:

mount -F hsfs /path/to/sol-nv-b101-x86-dvd.iso /export/loop
cd /export/loop/Solaris_11/Tools/Installers
./liveupgrade20

*Now* you can run all the LU commands:

lucreate -p rpool -n snv_101
luupgrade -u -n snv_101 -s /export/loop
luactivate snv_101
init 6
shutdown -i6 -g0 -y  (if init 6 doesn't reboot - maybe I was impatient)

P.S. Don't put the .iso on your root pool or it will be included in the filesystem forever and you won't be able to get that space back. Thanks Tim

I comment on a lot of random sites and blogs. I usually write down the URL in a text file and hope that someday I'll remember to return to see if there's a reply.

I believe a service exists - I know that "page change notification" services exist, but I'd rather be able to subscribe to an RSS feed of reply notifications - i.e. I post on a blog, I dump the URL into a textbox, and it monitors the site every so often for changes (probably the specific post's comment feed is the only thing that is worthwhile) - even better, someday maybe even automatically adding the URL when the browser notices I've commented.

Anyone got a site out there that does this yet? I've had this on my mental radar for a while. Of course, that doesn't really do anything if I can never get around to finishing anything.

I think I keep my machines pretty well up to date. I'm fixing up my girlfriend's computer right now, and I finally got all the updates applied except apparently one got missed. Okay, simple enough right?

Step #1: Install .NET Framework 1.0, click "Check for updates" - what? there's another update?

Step #2: Install .NET Framework 1.1 Service Pack 1, click "Check for updates" - what? ANOTHER one?

Step #3: Install .NET Framework 1.1 Service Pack 1 security update, click "Check for updates" ...

Really? Why couldn't we have a pre-packaged full install? Why do I have to run this "check for updates" over and over (and why does it take so goddamn long nowadays?)

Okay, looks like that really was the last update and this machine is now 100% up to date. At least for the moment...

Note: this has been outdated now. I have an updated post with the latest and Igor-approved method here.

When I was switching over to nginx, I found a handful of random and overkill config examples to make it work. I thought I had found the simplest solution already, but Igor (the creator of nginx) actually gave me an even "better" solution in nginx.

1st example (seems like overkill, can't figure out a reason why people are splitting up the rewrite rules - I guess because they assume "wp-anything" is all static?):

if (!-e $request_filename) {
   rewrite ^([_0-9a-zA-Z-]+)?(/wp-.*) $2  break;
   rewrite ^([_0-9a-zA-Z-]+)?(/.*\.php)$ $2 last;
   rewrite ^ /index.php last;
}

2nd example (this was as good as I thought it could be, but I was wrong):

if (!-e $request_filename) {
   rewrite ^(.+)$ /wordpress/index.php?q=$1 last;
}

3rd example (this is the best, according to Igor):

error_page 404 = /wordpress/index.php?q=$uri;

(Ref: http://article.gmane.org/gmane.comp.web.nginx.english/4739)

In the past, I've always been able to disable IPV6 in Linux with a simple line in any /etc/modprobe.d file:

alias net-pf-10 off

It appears though it has no effect anymore. I had to change it to this line:

blacklist net-pf-10

How annoying.

For the most part, open source has been good to me. I can run my business on free software that is for the most part better than its commercial counterparts. I'm able to use often-updated and relatively bug-free software in all facets of my life. However, there are a couple things that have been bugging me - one of them has been SATA Port Multipler (PMP, not to be confused with PM - Power Management!) support. 1TB drives hit an all time low last week (at least in my ads) and it got me motivated to check in to the status of PMP support once again. Previously there weren't a lot of people using it and not a lot of feedback or information. Today, I have a bunch of good information, but still not the magic combination, which for me, includes ZFS (as it is the only filesystem out there still to offer all the good checksumming, self-healing, etc.) This post isn't going to talk about why ZFS rocks. Most people already know why. I want a filesystem that has been built for integrity. This is for home archiving, and I'll be damned if bit rot is going to ruin my memories.

My goal was to find an OS that has ZFS support, which currently is between Solaris (or OpenSolaris, Nexenta, etc.) and FreeBSD 7 (which has "experimental" but usable ZFS support) - I'd prefer Linux as it has the fastest rate of bug fixes and driver support and I am already using Linux on one of my home machines, but ZFS doesn't run natively on it (FUSE is not native enough.)

The following below are the current status I am aware of taken from direct emails exchanged with Adriaan de Groot (who said he might port PMP support to FreeBSD 7) and Tejun Heo (who maintains the PMP driver libata-pmp for Linux) and Google searches, mailing list and forum postings as of today.

Windows

I'm not even going to bother here. Most drivers for the controllers are coded for Windows first, and then if we're lucky an open source Linux/etc. version is put out. So Windows support is probably 100% - but you're stuck to using NTFS or something (blech.)

FreeBSD

According to Adriaan:

"Don't bother, as port multipliers are not supported. I had some PMP support hacked in at some point, but without NCQ there's not much (performance) point. It *might* be that Soren has added NCQ / PMP in the meantime, but I'm not aware of it."

Also:

"PMP requires NCQ to be useful; otherwise you end up queuing all the requests for the different disks and performance goes down a fair bit - but like I said, it's *possible* and if all you're after is big storage, it will work. Anyway, it's not the cards' fault: there just isn't any NCQ in the (FreeBSD) kernel."

Tejun's comment:

Although NCQ and PMP supports don't really have to go together. Non-NCQ PMP should work as good as direct non-NCQ. Nothing more to lose there because it's attached via PMP. Maybe they were talking about pushing multiple commands to a port. If the driver can't do that, PMP won't work too nice. 

As of now according to Adriaan, there is no PMP support in FreeBSD (except possibly some highly experimental patches.)

Solaris (and variants)

From Adriaan:

"I run OSOL ... but OSOL also does not support PMP"

Additional links:

• http://www.genunix.org/wiki/index.php/OpenSolaris_Storage_Developer_Wish_List
• http://www.mail-archive.com/zfs-discuss@opensolaris.org/msg13192.html
• http://www.opensolaris.org/jive/thread.jspa?threadID=49507&tstart=45
• http://www.opensolaris.org/jive/thread.jspa?threadID=54481&tstart=45
• http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=6409327

OS X

Possibly? I did not look into this. It would be a shame if some were supported with NCQ and not given back to FreeBSD... this guy claims to have what sounds like two 4:1 multipliers on his Mac:

http://www.mail-archive.com/zfs-discuss@opensolaris.org/msg13749.html

Linux

(There is a site that tries to keep up to date with SATA support in the Linux kernel. This is probably the best place to look. As of writing, it still appears up to date. http://linux-ata.org/driver-status.html)

According to Tejun, who was extremely helpful answering my barrage of questions gracefully, it does look like Linux has some PMP options (now if only we had ZFS or BTRFS...!) with the following notes for each chipset:

Controller chipsets: SiI3124, SiI3132 - both will work. His comments:

"3124/3132 controllers are good"

"Performance-wise, all the PMPs on the market should be okay but 3124/3132s have certain limitations on PCI bus side and can't deliver full bandwidth concurrently from all drives attached through PMP. I don't remember the exact numbers but it maxes out after three drives or so."

"I have second gen chips from SIMG and they behave really good."

Note: SiI3124-1 is only 1.5Gbps. SiI3124-2 supports 3Gbps.

Enclosure chipsets: SiI3726, SiI4726, Marvell 88SM4140  - all should work great. His comments:

"3726/4726 PMPs are the first gen PMPs and both are a bit quirky"

"Marvell port multipliers behave really well."

"That said, 3726/4726's work okay too. The only problem is that they always need their first slot occupied to operate correctly. As long as you occupy the first slot, there shouldn't be much problem."

Update: "There have been reports of 3726/4726 PMPs having trouble with 3Gbps link speed under certain configurations. I still don't know what's the exact cause.  It doesn't seem common but if you can maybe trying out with one drive before ordering the whole array is a good idea."

Note: the Marvell is only a 4:1 multiplier, the SiI ones are 5:1.

So the big winner here for the time being is Linux - looks like I will be purchasing a SiI3124-2-based controller (probably this one, which claims it is a 3124A, a successor of the 3124-2) and a SiI3726 or SiI4726 based PMP enclosure. I am trying to determine which one will be the quietest right now. I don't believe that hardware RAID-5 is supported on any PMP, only RAID 0, 1, and 10. It gets confusing because most advertise RAID but it leverages some software RAID stuff. So I will probably using mdadm for RAID5 at home.

Hopefully this is a useful (and correct) summary. I invite anyone with updated information to leave a comment, and I will correct it. Especially if you have experience with eSATA PMP enclosures and have anything to add! Not many people have ventured out into these waters yet, but it looks pretty neat - off a single PCI-X or PCI-e card you could chain 20 drives all with decent bandwidth and only have one cable for each set of five drives...