My Technical Blog - Latest Comments

Re: View and Filter Orders Grid with Product SKU

Colin Mollenhour — Thu, 12 Apr 2012 00:15:50 -0000

Hi Andrew, I have not yet tested in 1.6, only 1.4.1.1. I will probably be testing it though within the next couple weeks.

Re: View and Filter Orders Grid with Product SKU

Andrew — Thu, 12 Apr 2012 00:13:53 -0000

Hi Colin, I am wondering if this will work with version 1.6.2?

Re: Benchmarking Zend_Cache backends for Magento

Colin Mollenhour — Thu, 08 Mar 2012 19:43:05 -0000

Steve, I'm not following.. Your example proves that the processes don't share APC caches. If you ran the benchmark on the CLI with APC each process would be hitting an empty cache and actually have a performance advantage because of it and therefore the results would be meaningless. APC is really designed to run within mod_php or php-fpm.

I'm sure the script could be modified to run off of your web server with some work. However, I'm not really concerned with using APC as a cache backend because what eventually happens is the user cache starts filling it up and evicting the opcode cache. APC is a great opcode cache but everything starts to suffer if you use APC for both opcode and user cache unless you just give it a ton of memory. Right now my system uses up to 150Mb for the opcode cache. To run the user cache on APC without risking the user cache evicting opcode cache I'd have to give APC at least 600Mb and that just seems to grow as new features are added or if the cache hasn't been cleared in a long time. Using Redis with compression enabed for records over 20kb my user cache uses no more than 128Mb.

Re: Benchmarking Zend_Cache backends for Magento

Steve Holdoway — Wed, 07 Mar 2012 15:49:26 -0000

Well, technically *any* process attached to a shared memory segment will keep it alive - it's not *in* any process - last one out turns off the lights.

If you use memory mapped files ( and who wouldn't - saves all that pesky kernel reconfiguration! ), then the segment is private. It will not affect any currently running processes, and your benchmarks will be more relevant.
$ php --info | grep apc.mmap_file_mask
apc.mmap_file_mask => /tmp/apc.zUiMm1 => /tmp/apc.zUiMm1
$ php --info | grep apc.mmap_file_mask
apc.mmap_file_mask => /tmp/apc.V0wyAu => /tmp/apc.V0wyAu

Or is apc just generating an unique file descriptor to the existing segment and fooling me into thinking it's private? It's easily done...

Re: Benchmarking Zend_Cache backends for Magento

Colin Mollenhour — Wed, 07 Mar 2012 10:16:15 -0000

Enabling APC on the cli actually hurts performance since APC caches opcode per-process. This works for e.g. apache because the cache lives on in the apache parent process between requests, but for CLI the cache is re-built for each process and lost at the end of the process. apc.enable_cli is only for debugging purposes for APC developers and should never be used in production.

Re: Benchmarking Zend_Cache backends for Magento

Steve Holdoway — Tue, 06 Mar 2012 15:26:36 -0000

If you add

apc.enable_cli = 1

to your php configuration, then you can then use APC from the command line. This will make the benckmarks a lot more relevant.

Re: View and Filter Orders Grid with Product SKU

Colin Mollenhour — Sat, 03 Mar 2012 15:32:56 -0000

That works nicely, group_concat is a bit more flexible than I thought! I just pushed an update that uses a custom column renderer and makes whether it displays and filters by SKU or name configurable. It uses the title attribute so that whichever is not displayed can be read with a mouse hover. Cheers!

Re: View and Filter Orders Grid with Product SKU

Tom — Sat, 03 Mar 2012 14:56:44 -0000

Got it. I prefer the product names so commented out SKUs and change the SQL in the 'names' var to:

'names' => new Zend_Db_Expr('group_concat(concat( \'(\', TRUNCATE(`sales/order_item`.qty_ordered, 0), \') \', `sales/order_item`.name) SEPARATOR "
")'),

Will create something like this in the grid:

(1) Product 1
(14) Product 2
(3) Product 3

Thanks again for the post.

Tom

Re: View and Filter Orders Grid with Product SKU

Colin Mollenhour — Sat, 03 Mar 2012 14:28:42 -0000

Hi Tom. Group_concat has it's limitations so probably the best way would be to write a custom column renderer that renders the qtys. I'll see if I can cook something up quickly.

Re: View and Filter Orders Grid with Product SKU

Tom — Sat, 03 Mar 2012 12:15:45 -0000

Works like a champ! I had created a similar module using the Inchoo method but you can't search by sku or product name using their method. Can search with your method. One thing missing is item quantities per item. This is something that we depend on so I will dig in a bit more to see if it can be added simply. Any suggestions? Thanks for contributing this to the community.

Re: Benchmarking Zend_Cache backends for Magento

Colin Mollenhour — Wed, 15 Feb 2012 00:22:49 -0000

I don't know much about Magento-specific hosting companies, just VPS and dedicated hosts. There was a short period where I had pulled in some changes that added more garbage collection but it was very detrimental to performance and not necessary so I removed it. I'm sure if Nexcess were to test the current version with a real benchmark they would see a huge difference in tag cleaning performance. Memcached is probably comparable for read performance though.

Re: Benchmarking Zend_Cache backends for Magento

saho — Tue, 14 Feb 2012 13:08:55 -0000

Do you currently know of any hosts that support Redis. We have a sip400 dedicated server from nexcess and they say they cannot support this. Its too bad because we have around 100k products and our add to cart functions are so slow. They said they set this up with another client and saw no noticeable difference in speed which is hard to believe with all the good things I am hearing about it.

Re: Benchmarking Zend_Cache backends for Magento

Colin Mollenhour — Thu, 09 Feb 2012 14:16:27 -0000

I use the Redis backend by itself, no two-levels. While you could use it as either the fast or slow (or both) in a two-levels configuration, in most cases it won't make sense to do so as the tag support built in uses Redis' efficient data structures to support tagging much more efficiently than the two-levels implementation.

Re: Benchmarking Zend_Cache backends for Magento

Alexandre Piel — Thu, 09 Feb 2012 03:48:13 -0000

Are you using Redis for the fast backend only or for slow and fast backend?

Re: Benchmarking Zend_Cache backends for Magento

Colin Mollenhour — Fri, 30 Dec 2011 17:08:40 -0000

Hi Sanjay, this sounds like an issue with the driver and corrupt cache records. Are
you using the phpredis (compiled) mode or the standalone mode? Please open an issue on the github project to continue discussion. -Thanks

Re: Benchmarking Zend_Cache backends for Magento

Sanjay — Fri, 30 Dec 2011 13:04:06 -0000

Hi Colin, a little bit of background first - our Magento installation is split into Admin and Frontend being on different servers. We installed your tool on the frontend and it works really good. The redis server had been setup on the frontend server, we then configured the Admin to talk to frontend Redis but when we access the admin url, we get the error "invalid server response: e_1>0Alt_Image", is there any direction you can recommend for solving this?

Cheers
Sanjay

Re: Benchmarking Zend_Cache backends for Magento

gwillem — Tue, 11 Oct 2011 20:18:09 -0000

Hi Colin, it looks like a promising tool, thanks for sharing! I'm really looking forward to your post about Redis as I want to convince my customers to switch over from memcache. Keep up the good work.

Re: Benchmarking Zend_Cache backends for Magento

Colin Mollenhour — Mon, 10 Oct 2011 19:42:30 -0000

Yes, absolutely.

Re: Benchmarking Zend_Cache backends for Magento

Anonim — Sat, 08 Oct 2011 12:33:37 -0000

Can your backend be used without magento? Like normal Zend_Cache backends ?

Re: About

Colin Mollenhour — Sat, 01 Oct 2011 17:17:12 -0000

Hi Justin. If you don't want to check third-party code into your repo then you can just check in a list of extension keys (extensions.txt) then use a shell command to make sure they are installed:

@shell \
cd $PROJECT; \
mkdir -f .installed \
for ext in `cat $MODULE/extensions.txt`; do \
if [ ! -f .installed/$ext ]; then
./pear install $ext && touch .installed/$ext; \
fi \
done

Re: About

Justin — Sat, 01 Oct 2011 16:55:49 -0000

Hi Collin, I'm looking forward to using Modman, which seems like a great utility. I just have a question about best practices when it comes to 3rd party Magento extensions. This must be a simple or obvious question as I haven't been able to find anyone addressing it online, but in a nutshell: is there a best practice for dealing with 3rd party extensions when developing a Magento store, using source control and modman? I'd rather not check 3rd party extensions in, so are they something that wouldn't even typically be handled by modman? Just install the extensions I want by hand in my production, staging and dev environments individually? Thanks for any thoughts you may have

Re: About

Colin Mollenhour — Sun, 11 Sep 2011 22:57:03 -0000

Maybe your comment didn't come through as expected, but I think
you're asking about configuring a prefix to avoid keyspace collisions?

The Redis cache does not use a configurable prefix. If you run more than one Magento installation on the same Redis server with the same database is then you will definitely have keyspace collisions. I
would recommend using a different Redis database for each Magento installation. This can be done with global/cache/backend_options/database. You could also run a separate instance of Redis on a different port, which would let you control
the amount of memory each installation can use.

Re: About

Alex — Sun, 11 Sep 2011 18:51:37 -0000

Hi Collin,
I have a quick question about Magento config for Zend_Cache_Backend_Redis.
For APC cache, in case of multiple websites/per server you need to use '<prefix>..</prefix>' . Do you need to do anything like that if you are using Zend_Cache_Backend_Redis ?
Thank you!

Re: About

Colin Mollenhour — Fri, 26 Aug 2011 23:01:05 -0000

Yep: @colinmollenhour

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Re: About

Vinai — Fri, 26 Aug 2011 17:39:23 -0000

Hi Collin, do you twitter?