Get an Airport Extreme

Wow! So I haven't blogged in forever, but I had to write something about my experience with my new Airport Extreme...

I had a trusty, well, rusty Linksys Wireless-G. I know what you're thinking. So the short and skinny is that it was about 6 years old and over the course of a couple days choked and died recently.

Being the ignorant wireless router geek that I am, I stepped into Best Buy and looked at the dozens of products they had in stock. I was a bit cost sensitive so I asked one of the sales guys what my best options were. Mistake number one. As much as I hate to say this, this is the 3rd time I've been burned by one of these guys... I told him I needed something solid as I work from my home office and that if the features outweighed the cost I'd go with the better product.

I ended up getting a NetGear N600 trusting that this was the best option after the consult. Of course it helped that the box had "HIGH PERFORMANCE" on the box. What malarkey... I am a regular Skype user and after getting the router in place I continually dropped calls to the point where for the 3rd time I was dropped in discussion with a co-worker he stated don't call me back until you get a new router.

He advised on the Airport Extreme so I purchased online from Apple. It was delivered via ground in a few days. MAN!!!! This thing opens up the pipe!!! No more dropped Skypes, flying downloads. I won't get into the specifics why as I have to run, but get one now if you value a great web/net experience.

Link to Apple Store: Get IT!

jvm.config Tuning Tip For All Server Side Java Solutions

I have been wanting to blog about an experience I had not too long ago on a project where the jvm was consistently throwing OOM errors. It had me banging my head against my desk for a few days attempting to trace where the culprit was.

Was it code related?... yes, was it bad code?... sort of, was it very very very intense code (looping over many sql calls and instantiating many objects)?... YES! The challenge here was to apply a quick band aid rather than redesign this rules engine that had the characteristics listed due to time constraints. It is important to note I was not responsible for the poorly written code 8-).

I had to first identify if there were memory leaks due to this code. To do this I utilized YourKit Java Profiler. They have .NET and Java profilers that allow you to monitor their respective runtimes. YourKit Profiler is very simple to configure within the jvm.config file (I'm not going to get into that in this blog). My point here is that I witnessed memory steadily climb and at times spike, but was only able to reclaim memory when executing a manual GC. UGGG!!! So, no memory leak, but the runtime was hanging on to what it had... Why was the GC not reclaiming memory quickly on it's own? I had all the BP jvm args of old, etc., etc. ParNewGC and RMI to no avail.

And to get back to the initial issue; the blasted OOM error. I searched high and low and identified a thread on a Sun forum that there were issues with jre 1.5 that ultimately threw a OOM error if the runtime was unable to reclaim memory during a GC within a given time frame. The workaround for this was to set a time constraint in the JVM (which didn't work) or install 1.6_10 or later. This was my first step. I installed this JRE version and pointed my jvm.config to it. The application ran fine under this JRE except that I was still seeing the memory creep to the ceiling with no reclaim.

I then read on one of Sun's GC tuning white papers the following paragraph:

The -XX:+AggressiveHeap option inspects the machine resources (size of memory and number of processors) and attempts to set various parameters to be optimal for long-running, memory allocation-intensive jobs. It was originally intended for machines with large amounts of memory and a large number of CPUs, but in the J2SE platform, version 1.4.1 and later it has shown itself to be useful even on four processor machines. With this option the throughput collector (-XX:+UseParallelGC) is used along with adaptive sizing (-XX:+UseAdaptiveSizePolicy). The physical memory on the machines must be at least 256MB before AggressiveHeap can be used. The size of the initial heap is calculated based on the size of the physical memory and attempts to make maximal use of the physical memory for the heap (i.e., the algorithms attempt to use heaps nearly as large as the total physical memory).

Note: -XX:+UseAdaptiveSizePolicy is on by default so I don't explicitly define it in my args.

Amazingly, once I added this to the args, removed ParNewGC (enabled UseParallelGC) the server ran flawlessly for days and days without a restart. I was serving requests into the millions without a restart!!! A partial arg list specific to these setting are below, please let me know your thoughts and concerns as I always enjoy constructive feedback.

java.args=-server -Xmx1024m -Xms1024m -XX:+AggressiveHeap -XX:+UseParallelGC -Dsun.io.useCanonCaches=false -XX:MaxPermSize=512m

Note: This was for a ColdFusion 8 instance.

Thank You Greater Miami Chamber of Commerce

I spoke to the GMCC yesterday afternoon about SEO and how Universal Mind has overcome the challenges of spidering flash based solutions.

It was an enjoyable presentation and I appreciated the genuine interest and questions from the attendees. Thank you Chamber! I look forward to visiting again. The "download" link below will allow you to save the PowerPoint presentation.

ColdFusion createObject "Component" and Pathing Performance

I haven't blogged in awhile due to schedule, but had to blog this experience I recently had while attempting to stabilize an application and enhance performance.

I have always taken for granted that createObject was lightning fast... Well, as fast as feasibly possibly under a given JVM.

I think I was dead wrong and this may be an issue for Adobe to address. I am unclear on the internals of course. But I have been up against OOMs on my current project and wanted to test out using soft reference (cached objects) and use duplicate from the cache rather than createObject.

Far stretch I know... but hey it was worth a try. What was revealed was that performance was negligible and createObject was faster in some intervals. Memory behaved the same, no real bonus. So in discussion with a fellow consultant I told him I'd ship a zip to him for test purposes as he had said he'd seen a significant performance enhancement with duplicate (not true by the way).

What happened next totally shocked me. To simplify the test code I snagged my VO.cfc out of it's proper place (several dirs down i.e. sitedir, com, bus, app, model, vo.. you get the idea) and put it in the root of the calling cfm. I then removed all the pathing (dot notation) from my createObject call and executed the cfm to see if it would run ok after the change.

The test was a loop of 10k over this create object call. I was seeing execution times of around 30 seconds. When I ran the updated code it went to 577 milliseconds... I am still befuddled by this. Is there that much overhead with pathing?

I initially thought it was a mapping issue because I had been using mappings, but absolute path from root was just as slow.

Please Adobe tell me this is Sun's jvm and not your code. I know this is negligible with 100 or so creates, but imagine the boost if I did find something here.

For clarification I am running on a Mac (OS X, CF running in JBOSS), but also tested on my old Dell (XP, CF running in JRUN). I didn't see as dramatic a difference on WIntel, but my exec time went from 30 seconds to 4 seconds. I am happy with 10x faster on Windows too...

Any insight here is greatly appreciated. Example Code:

<cfscript>
      currentTime = now();
    rqaArray = arrayNew(1);
    initTime = getTickCount();
         for (index=1; index lte 10000; index = index + 1)
{
    // pathing example replace vo reference with     //this pathing call com.mercer.mercerOnline.model.RQASummaryVO
    rqa = createObject("component","RQASummaryVO");
    rqa.rqaID = index;
            rqa.type = "theType";
            rqa.createDate = currentTime;
            rqa.submitDate = currentTime;
            rqa.client = "currentClient";
            rqa.clientID = "clientID";
            rqa.status = 6;
            rqa.userID = 123456;
            rqa.agencyID = "agencyID";
            rqa.predecessorID = 0;
            rqa.locked = false;
            rqa.deleted = false;
            rqa.title = "The Title "&#index#;
            rqa.policyNumber = "thePolicyNum";
            rqa.agencyName = "agencyName";
            rqa.totalPremium = "totalPremium";
            rqa.hasMessages = false;
            rqa.isAssigned = false;
            rqa.assignedTo = "";
            rqa.proposedEffDate = currentTime;
    rqa.proposedExpDate = currentTime;
    rqa.agentName                     = "agentName";
            ArrayAppend(rqaArray,rqa);
         }

         endTime = getTickCount();

         totalTime = endTime - initTime;
</cfscript>
<cfdump var="#arrayLen(rqaArray)#">
<cfdump var="#rqaArray[10000]#" />
<cfdump var="#totalTime#" />

Why VOs (transfer objects) are good...but they can be abused like...

any other design pattern....

Sorry for the confusing title, but long titles are rather lame. So you're a flex cf, java, or php developer and you are leveraging all the beautiful one to one mapping associated with server and client object creation.

"YES!", you said. No more guess work; my server vals returned can be readily passed around within my AS code with the ease of code insight! Ctrl-space... wow theres my property! Ok, getting tacky I know.

So we embark on our design of a sytem always using VOs no matter the cost. Eee gaadd stop now. VOs, pending on design approaches may possibly have multiple layers of nested VOs YIKES!

Everyone knows that Rambo's weapons of choice were the bone cutting hunting knife and explosive bow and arrows. But there were times when he had to pull in the heavy artillery or perform a sneak attack with a much more lightweight approach like a choke hold (ahh, the violence of my youth...).

This is why VOs can be a problem if implemented without understanding the performance ramifications that can be incurred if they are always used.

Here's a real world scenario. Requesting an array of 100+ VOs from your middle tier that each have nested arrays of child VOs. Imagine just having two child VOs and the impact that could have on performance with this approach.

You call in to pull back the parent VOs that contain an array of child VOs (say 5) that all need to get created for each item in the array. So in this process we are creating 100 parent objects and internal to each we are creating 10 child VOs. This yields 1000 objects which each need to get created and the memory and process grow each time you do so on your middle tier (now add just a few users doing this incrementally over the first couple of hours).

I'm being facetious here of course as this isn't a very high number. But why return such a dense object to the client unless you were going to use it. There is a lot of wasted horsepower with this approach. Think of the scene with Rambo emptying that M60 E4 machine gun and never hitting his target... Rambo

A better approach is to pass back a snapshot of the data directly from your middle tier and pull back its VO representation when an edit needs to be performed or the VO truly is required to facilitate a process in the application.

So if you are going to populate a grid, I don't recommend doing it with VOs and if you absolutely have to create an array of VOs understand the possible performance impact (and data stagnation) that can ensue if the VO is of a complex nature and how it can impact the health of your server and ultimately the user experience.

The J2EE Core Pattern docs on Transfer Object speak to this. Check out the "Consequences" section of caching large sets of VOs. Line from the article: There is a trade-off associated with this strategy. Its power and flexibility must be weighed against the performance overhead... THE LINK

Flex ColdFusion Extension Wizard Gotcha

This entry will hopefully be brief and to the point in regard to the title. I want to start off by stating how much I like the ColdFusion extension support in Flex 2 and hope to see Adobe add extenstions that support other languages/middle tier solutions as well hint: (java, php, c#).

There is nothing like beginning your application architecture and development with an out of the box mvc approach utilizing well known approaches to server side development utilizing delegates, services, daos, gateways, and value objects.

Where I see a major problem with the extension is how it is implemented. I have been involved with several projects that have utilized Flex and ColdFusion and upon initially beginning my trek into Flex 2 I saw this issue right away only because I have been working with ColdFusion for 10 years, have consulted on its benefits, scaled servers, architected highly successful and efficient enterprise solutions with it, and know the do's and don'ts...

The problem I am speaking of with the CF extension implementation is the iterating over read functions in the data access object cfcs.

To be more clear, in the templated or skeleton dao cfcs there are db calls made, mostly crud calls. The read function I am discussing here is "r" in crud. The problem is that in many cases I've seen engineers design a composite or aggregate VO. This is a VO cfc that contains other VO cfcs.

This is a perfectly efficient and best practice OOP approach that ColdFusion handles very well. The problem arises when a child resultset of ids (usually a query or array) is used to iterate over and call the read function in the dao to get the vo properties from the db to return via remoting to the Flex application.

The main issue here is performance, specifically with the possible 100s of calls that can be made to the database in one ColdFusion request from the application. Imagine a dump truck going 200 times to the gravel pit taking one pebble, with today's gas prices I don't think you'd last long on the job if you took that approach 8-)... This is what you are doing when you loop over queries. Not only could these calls prove to be slow and taxing on the database but it can also lock up threads in ColdFusion and create cpu and memory spiking out of the shoot. You also have to deal with any kind of network latency that may exist between your CF server and the database as well. AAAACKKKKK!

But there is a solution: First a band-aid needs to be applied. For these complex objects an investigation must be made to locate where these iterating processes could be going on. Second, there is a function in ColdFusion that automagically converts a query field to a comma-delimited value list(or delimiter of your choosing). The function is called "valueList(query.column, ',')" there is also a quotedValueList for strings. With this list you could then use the SQL IN clause on the hopefully indexed id field used to pull back the child VO data. Add another function in the dao or better yet the data gateway that specifies readMultiple or getMulipleObjectName...

Once this is done the code should truly be refactored to call the database only once for all its data (think one cf call/one db call). If you did not know ColdFusion is one of the most robust languages when integrating with the more popular dbms on the market (Oracle, SQL Server, MySQL, DB2, Informix). The cfstoredproc tag allows you to call into a stored procedure to get procedure resultsets.

cfstoredproc also allows a developer to return multiple resultsets from a stored procedure to ColdFusion. So, one call to a stored procedure in Oracle that returns 2,3,4,or more ref cursors to ColdFusion. These could be all your objects' data which only requires you to loop once over all of them (maybe some nesting and brief logic to create them, but still 1000s of times faster than separate db calls for each loop).

This may be one of the drier entries I've had (no code, pictures, jokes). But I hope it helps you when using and not abusing the ColdFusion extension wizards in Flex 8-).

MapQuest's AS3 API in Beta

I recently assisted in developing and testing on the API Development and QA teams for this product and wanted to share some information on their new Actionscript 3 API with the community.

If you are interested in mapping GIS related data (what data doesn't have a GIS component?) or are currently working with competing products you should evaluate what MapQuest has to offer with their new AS3 API. I can't stress enough the concentrated effort that went in to streamlining the integration process, performance and speed, and feature set.

The Libraries:

  1. AdvantageAPI.swc - Actionscript Library used for retrieving geographical data from mapquest servers
  2. TilemapToolkit.swc - Actionscript Library used for creating a tilebased map
  3. TilemapComponent.swc - Flex Library used for placing tilemaps within MXML

With the above libraries you can acquire geocode information for existing address information, place points of interest on a map, utilize vector based overlays, and fully customize all built in MapQuest default features such as the zoom and pan controls.

It is important to stress that with MapQuest's API you can customize the entire look and feel of the map to suite your business (logo etc.)

It is important to stress some of the peformance gains I noticed from the legacy html and javascript based solution. Most importantly the speed in which POIs (points of interests) can be added to a map. I witnessed a 500 poi legacy application load 500 pois in 10 seconds and via the AS3 API load the same 500 POIs instantaneously. Imagine this performance benefit if you were to embed a map in a desktop app written in AIR?

If you are currently utilizing MapQuest and have standardized on javascript or don't foresee spending this years budget on converting to AS3, that is ok, you can utilize a version of the API wrapped to support javascript integration, which should allow you to drop the new flash based solution in to your existing javascript/html/AJAX solution.

There are many more advanced features such as POI decluttering, customizing POI graphics, and display windows to name a few. There are also Flash CS3 supported swc libraries that can be imported in to the Flash IDE as well.

MapQuest went above and beyond to make integration with Adobe products seamless.

The following links will detail some of the release information and how to get ahold of the libraries:

Links to various MapQuest sponsored information and links:

Snapshot:

oobgolf.com MapQuest Application

Simple Cluster Setup With CF 8

Last evening I installed ColdFusion 8 for a client and setup two instances outside of the default cfusion for clustering. Gone are the days of MX when one had to access jrunsvc or jrun itself to create a Windows Service for the instance or stop and start the instance via the command line. ColdFusion 7 had these features as well, but I wanted to note ColdFusion 8's continued support of clustering. It is a bugless or for lack of a better term "gotchaless" task that if all ducks are in a row can take minutes to configure in its entirety, including install of ColdFusion, import of legacy CAR file, creation of instances (deployment, etc.), and configuring the cluster.

For those that are looking for CF 8 documentation on clustering ColdFusion it is located here: CF 8 clustering.

I would like to see an updated approach to clustering with CF 8 and BIG IP (hardware load balancers in general). Some of the more advanced topics, are a bit out of date and at this time many companies are upgrading their hardware infrastructure and would benefit from this updated information.

Flex and ColdFusion "They're in the Game..."

I recently assisted XOSTechnologies, Inc. in clustering their ColdFusion servers with a bit of development to support a site they engineered with a full Flex 2.0 front end utilizing Flash Remoting (AMF) to ColdFusion 7.0.2 cfcs (ColdFusion talking to Oracle). ColdFusion processes are monitored by SeeFusion.

The site was built to support the EA Sports gaming community and their release of some of the most dynamic sports gaming software to date. The site is a social community which allots for picture and video upload as well as messaging, forums, and that's not all. You should check it out at EA Sports World.

For details on their infrastructure as they are "doing it right" feel free to send me an email.

ColdFusion Version Chart

I was recently doing some research with regard to a customer's version of ColdFusion and thought that this would be helpful. Adobe keeps a chart of the versions of ColdFusion at this link.

Why is this important you may ask? Well, as in every software package there are patches and updates that come on-line as the product matures. In past cases there have been versions of CF which have had issues that a patch or update resolved. With any update it is important to conduct preliminary tests of your current environment with the update in a test or staging area to resolve any issues that might arise, though it is rare to see an updater to CF result in an unstable machine.

To locate the version of CF that you currently have installed, open the CF administrator and browse to Settings Summary. You will see version information at the top of the screen output. It will look something like this:

Version Information

Server Details
Server Product

ColdFusion MX
Version

7,0,2,142559  
Edition

Enterprise  

Serial Number

Not displayed to protect the innocent 8-)  
Operating System

Windows XP  
OS Version

5.1  


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