ColdFusion Muse

ColdFusion Debugging on Production

Today's short note is brought to you by "Don't Do That On Production!" At CF Webtools often times we get called in to help troubleshoot servers that are failing to perform well. We often hear the same sort of symptoms that goes like this. The server has been running fine for months then suddenly for no reason it's slow, CPU usage is high, and it hangs or crashes multiple times per day. This always prompts us to ask the same question. "What was changed just before these symptoms started?" And the answer is usually "Nothing was changed (as far as they knew)". In all reality the person we're talking to may not the be only person with access to make changes to the server. Or they may not in fact have access at all and they are relying on information provided to them by an IT team member. We take notes, assume nothing, and question everything (on the server).

We had this scenario play out a few times in the past few weeks with three servers from three different companies. The reason I'm writing this note is the same problem occurred on each server. The short answer is someone enabled ColdFusion Debugging on the production server. ColdFusion is a very powerful rapid development platform, but it has a few gotchas if you are not careful. Such as enabling debugging on a production server. Debugging output provides a massive amount of information and for obvious security reasons we never want this enabled on a production server. Yes, I know you can restrict debugging output to a certain IP address, but that does not prevent the debugging output from being generated. It's just not displayed. The generation of debugging output takes more CPU power and at times more JVM memory. On a low load web application you may not notice a difference. However, on a high load, high traffic production web application the extra resources needed to generate the debugging output may in fact cause all those symptoms described above.

In each of the cases we saw these past few weeks, we were reviewing the servers settings, looking at the results of Fusion Reactor, and reviewing ColdFusion settings. On the first server we almost missed the fact that debugging was enabled. By the time we were troubleshooting the third server with similar symptoms we were checking to see if debugging was enabled before we did anything else. Disabling debugging resolved the bulk of the performance issues. We then used this time to review each server and offered additional performance tuning recommendations based on each servers resources and application needs.

This falls into the category of "Don't Do That On Production!" Please leave debugging to your development and staging servers.

CF Webtools is here to fill your needs and solve your problems. If you have a perplexing issue with ColdFusion servers, code, connections, or if you need help upgrading your VM or patching your server (or anything else) our operations group is standing by 24/7 - give us a call at 402-408-3733, or send a note to operations @ cfwebtools.com.

ColdFusion, SSL, SNI, SAN and Wildcards - Stuff You Need to Know

The Muse welcomes back his friend and colleague (and super genius guru) Wil Genovese with an timely post on SSL and Certificate types. If you have had your head in the ground (or perhaps you have been guest staring on "Naked and Afraid" or "Survivor") you may have missed the hubbub surrounding TLS, SSL and changes and support. There is a lot going on and it is more important than ever that you get your hands around the issue to keep your users safe. Wil has done Yeomen's work identifying the types of certs, the versions of ColdFusion and Java that support them, and work arounds and caveats for those of you who need them. You will likely want to bookmark this one. Take it away Wil.

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Surviving Poodle - ColdFusion and SSL 3

There's been a great deal of buzz about poodle. Poodle is an SSL exploit capable of highjacking a session using a browser's ability to "negotiate downward" the level of SSL it uses. It's recent prolifieration has put some urgency into the efforts to force existing applications and platforms to deny the use of any standard of SSL less than version 3.0. Super guru Wil Genovese (Trunkful.com) recently did some troubleshooting on a ColdFusion server with an issue related to this necessary configuration step. Wil writes:

We ran into an issue when a company contacted us at CF Webtools because ColdFusion was suddenly no longer able to connect to their email providers mail servers. One day ColdFusion was sending emails to their clients just fine and the next day it was failing. As you know these issues are usually best resolved by asking "What changed?" As far as the client knew, nothing had changed - but we knew enough not to stop digging.

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Side-by-side Configuration Error installing CF 11 on Win2008r2

One of my colleagues, Chris Tierney, was installing a pristine copy of ColdFusion 11 on a Windows 2008 server. He followed our standard protocol which is to install the server using the "built in" Web server, then create instances (we typically use multi-server mode) then use wsconfig.exe to connect the instances to IIS. It all went as planned until he tried to run wsconfig.exe (FYI - you must always run this as administrator). He got an error as follows:

Followed by an odd stack trace. After experimenting with permissions and googling he stumbled on Bug 3761543 in the ColdFusion bugbase. The issue is not very well documented. Apparently the MS C++ package installed on 08 is 32 bit. I'm not clear if we installed it or it shipped with 08, but remember, you need the MS C++ 64bit SP1 Redistributable. Here's the download link from Microsoft so you don't have to hunt it down.

The Fix

Microsoft Visual C++ 2008 SP1 Redistributable Package (x64)

One more time: This download fixes the "side-by-side configuration" when installing ColdFusion 11 on Windows 2008r2.

email connection crossover workarounds

As a follow up to yesterday's post (regarding sending mail and having it end up in someone else's "sent" folder) I thought I might put some flesh on the workaround suggested both in the bug report and on CF-Talk. The suggestion is to:

This idea is workable up to a point so I thought I would explore it for my readers.

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CFHTTP, IIS 8 and Server Name Indication (SNI)

Guest Post by Wil Genovese

(Muse Introduction)
Most readers know that the Muse is deeply indebted to a large and talented group of developers working here at CF Webtools. These folks solve problems and undertake Herculean programming tasks on a daily basis. They are constantly making me look good and I would not be able to play golf or spend the day wise-cracking in IM and tormenting my assistant Melissa without them on my side. Among these folks is one of my favorite characters, CF guru Wil Genovese. Wil has worked with us for a few years now and he writes an excellent blog at Trunkful.com. If you have not already done so, you should add it to your list of must read blogs.

Meanwhile, a few days ago Wil was trying to troubleshoot a head scratching issue with CFHTTTP and SSL. Now such issues almost always come down to getting the certificates properly installed in the keystore, using the correct URL (correct in all respects for the certificate), name resolution and SSL protocol levels (as in "do you need to lower Java's draconian SSL defaults to allow for less secure protocol"). After beating his head against the wall repeatedly Wil finally decided the issue was on the other end - the certificate on the server was somehow wrong, misconfigured or behaving unexpectedly. I thought this was dubious at best, but as is so often is the case the Muse was wrong and Wil found out (with apologies to Monty Python) something completely different. It turns out a new feature in IIS 8 (Windows Server 2012) was the culprit. Since this setting affects all Java versions prior to 1.7 and even affects CF 10 on Java 1.7, you should probably pay attention. My guess is that you will run into this issue eventually - given the ubiquity of IIS and the coming upgrades to Windows server 2012.

Anyway, I invited Wil to write the following entry detailing his findings. If you want to know more read on:

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Always Check on the Last Thing You Changed

If you can sing this with a sort of smarmy accent like Eric Idle it makes it really pop to the tune of "Always Look on the Bright Side of Life".

Your server's feeling bad,
It can really Make you mad,
JRUN maxed can make you swear and Curse,
When your chewing CFGristle,
Don't Grumble, Give a Whistle
And this will help things turn out for the best

Always check on the last thing you changed
(whistle cheerfully here)
Always check on the last thing you changed.

If CF's being Rotten,
There's something you've forgotten
And that's to check the freaking SVN,
For anything that's newish
Roll it back, don't be bluish
Just pucker up and whistle, that's the thing


Always check on the last thing you changed
(whistle cheerfully here)
Always check on the last thing you changed.

...I'm not sure what was in that mimosa...

Debugging and a Return to Dodge City

One of the things the Muse likes best about ColdFusion is the excellent debug information provided during development. Of course you should never ever leave debugging enabled on a production server. Not only are you generating a great deal of additional data with each request (adding overhead), you are potentially exposing a mother lode of technical information that a nefarious hacker would salivate to see. But during development, the debug information is where you ought to live. Indeed, if you are not constantly checking the debug information start doing it now - make a habit of it! You will learn things about performance, iterations, database interactions, cookies, paths, and all sorts of goodies that will make you a better programmer.

I've had my head buried in the debug information since I started with ColdFusion. Back then (in the Wild West days of CF 4.01) we never heard of newfangled ideas like "cfqueryparam". We just stuffed our variables into queries willy nilly and trusted the good Lord to protect us. It feels like I have spent the last 7 or 8 years cleaning up after code written like that. But writing queries in the raw (unprotected I mean... I don't generally code naked, although I did experiment in college) had one main advantage. As you probably know a lot of debugging goes back to the database. The debug output pre-cfqueryparam was "well formed" query code that could be copied and pasted directly into a query tool like MSSQL studio or Navicat. This made debugging pretty easy. You could swipe a problem query out of the debug, run it and tweak it unit it gave you what you needed, then past it back into CF. But that changed when we all started using CFQUERYPARAM.

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