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Create a Heartbeat Monitor for your Applications Using BugLogHQ

Wed, 25 Apr 2012 22:39:00 -0000

The latest release to BugLog (1.5.202) makes it very easy to build a custom "Heartbeat Monitor" to check the status of a web application and send you an alert via Email or SMS whenever there are signs of trouble. A Heartbeat Monitor is a process that periodically checks if an app is fine. This can be done in multiple ways, either by the monitored application "pinging" the monitoring application in a regular interval; or by the monitoring application asking the monitored application if everything is ok (on a regular interval too). In both cases if the monitored application detects that there is a problem (by not hearing from the app in a while, or not receiving the expected response) then it sends some sort of alert to a system administrator. The model we will describe in this post is the first one, in which the application being monitored (the "Target") contacts the monitoring application (BugLogHQ) in a regular interval. We will then instruct BugLogHQ to send us an alert whenever it hasn't heard from the target app in a set amount of time. On a follow up post, we will describe how to implement the second approach, in which BugLogHQ periodically checks the target app for its status and then tell us whenever there is a problem. There are two steps to build our monitor. First we need to modify our target application (the one that we want to see if it is OK) to periodically send a short message to BugLogHQ telling it that everything is great. The second step is configuring your BugLogHQ server to listen to these messages.

Step 1: Modifying the Target Application

The first thing you need to have is the BugLog Client cfc. This is a small coldfusion component (cfc) that knows how to talk to a BugLog server. If you are reading this, you are probably already using BugLog to keep track of your application errors, so the client cfc is already part of your application. If not, don't worry, there is not magic voodoo here. The gist of what we will do is create a scheduled task that will call a cfm template, which in turn will send an "I'm alive!" message to BugLog. Using your favorite editor or IDE create the following file: heartbeat.cfm

If you are using ColdSpring or some other sort of DI engine, then you can replace line 1 to whatever is appropriate for your application. The idea is to obtain an instance to the bugLogService.cfc component. Also, if you are wondering from where this CFC came from, you can find it in the BugLogHQ source code, inside the "bugLog/client/" folder. The argument to the init() method is the URL where your BugLogHQ listener endpoint lives. This could be located in the same server as your application (if you are running BugLog alongside your app) or on a completely separate location (if your BugLog has it's own server). Now you only need to add hearbeat.cfm as a scheduled task using your CFML engine's admin panel. How often to execute? well, that depends on how granular you want to be with your checks. The more frequent the heartbeats, the faster you can react to a downtime. For the sake of this example, let's set the scheduled task to execute every 1 hour.

Step 2: Configuring the Heartbeat Monitor in BugLogHQ

Ok, so now we have the target application happily sending an "I'm Alive!" message every hour to your BugLog server. Now we need to tell BugLog that this is a special message and that if it doesn't receive it then it means that the app is (likely) in trouble. To do that, we will create a new instance of the "Hearbeat Monitor" rule. So, log on into your BugLog server and head into the "Rules" section in the main menu. In the selection box next to "Create new rule of type" select "heartbeatMonitor" and click on "Go". Here is where we tell BugLog how to recognize our heartbeat messages. Here are the different settings and what they mean: Description: This is just a user-friendly text describing this particular rule. You can enter something like "Heartbeat monitor for application X" Timespan: This is how long to wait for a heartbeat message. In Step 1 we configured our scheduled task to emit a heartbeat once every hour, so in here we will set the timespan to 70 minutes (1 hour plus 10 minutes) to give it some extra time just in case the app server is busy. This is the amount of time the monitor will wait before it thinks that there is something wrong. Alert Interval: This controls how often we want to be notified if the app remains down. So if we set it to 30 minutes, once the initial alert of the app being down has been sent to us, BugLog will only notify us again once this amount of time has passed. Otherwise we would be receiving alerts every two minutes until the heartbeat messages are received again. Application: This is the name of the application sending the heartbeats. This is the application name as it appears on its Application.cfc. Host Name: Use this if you want to configure heartbeats for different hosts running the same application. Severity Code: This tells the monitor how to identify which messages to listen to. Remember that on heartbeat.cfc on the target app we used a severity code of "ping". Use that value here. Using a unique severity code is useful so that the heartbeat messages can be filtered out from the other "normal" messages and bug reports. Recipient Email: This is where to send the alerts whenever the target app appears to be down. You can add one or more email addresses here, or even use one of those email addresses that are linked to phone numbers to receive the alert via SMS message. Save the rule definition and then Stop/Start the BugLogListener service (in the BugLogHQ homepage) to make the rule go into effect; and that's it! So there you have it, you can now let BugLogHQ do its thing while you relax poolside drinking fruity umbrella drinks with the comfort of knowing that you will be alerted once your app starts getting into trouble.

BugLogHQ Version 1.5 Now Available

Mon, 21 Feb 2011 03:02:00 -0000

Finally I was able to put aside other projects for a little bit so that I could spend some time doing some needed updates to BugLogHQ. BugLog is a ColdFusion tool used to collect and aggregate bug reports from multiple applications on multiple servers. This update pushes the version number to 1.5. The main new features are: (from the readme.txt):

Extensions are now stored on a database instead of an XML file

Creating a rule instance is now much more user friendly because application, host and severity codes can be selected via dropdowns; or can also be prepopulated from an existing bug report.

Added support for defining settings for multiple environments (dev,qa,prod1,prod2,etc). Once the environment is detected buglog can override any setting with custom values.

Added option to disable editing settings through the UI (useful if you have your config file versioned and only want to configure buglog that way)

Added the "BugLog Digest" which is a configurable and periodic email summary of all reports received in the last X hours.

Rewrote the "iphone" UI to be for mobiles in general (now its accessible at /bugLog/mobile), also there is an improved platform detection when going to /bugLog. If you go with any mobile browser you should get redirected to the new UI, otherwise you go to the regular desktop UI

Multiple bug fixes

Download the new version from here Upgrading is pretty easy, you just need to replace your /bugLog folder with the new one and execute the appropriate sql script on your DB. You can find the upgrade scripts in /bugLog/install/migration/1_4_to_1_5/*.sql. Also, you might want to keep a copy of your /bugLog/config directory. After updating the /bugLog dir, you will need to manually edit the main config file in case you made changes to the default DSN/username/password values, all other config settings can be entered through the UI. The first time you login to the /hq admin UI you will be prompted to update your password. Also, if you have any rules defined, once you to the Rules screen, you will be prompted if you want bugLog to copy all your rule definitions into the database. Just click 'Yes' and sit back and relax while BugLog does the hard stuff for you.

New Mailing List

Also, I created a Google Groups mailing list to provide a place where anyone could go for help or post any comments, suggestions or random thoughts about BugLog. To join, visit: http://groups.google.com/group/bugloghq So, please take it for a spin and please let me know if anyone finds any bugs or find things that are not very clear. Have fun!

Getting MySQLNonTransientConnectionException errors? Then Your MySQL Server Might Be Angry At You!

Thu, 28 Oct 2010 18:34:00 -0000

Today I experienced one of those errors that are not related to the actual stuff that you are working on, but because of it you can't work on anything else. The error I was getting was:


com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: 
Could not create connection to database server. 
Attempted reconnect 3 times. Giving up.

This started happening while I was testing the DSN creation feature on my employer's website. You know the drill, trying different things, run again, put the wrong settings, run again, put the right settings, run again, and so on; until at one point I started getting the above error. No problem, I thought, lets restart Tomcat/ColdFusion.... Nope, same error... Let's check with the other devs to see if they have the same problem... Nope, everyone is fine.... Let's manually kill the connections from my host... Nope, same error... Let's drop the database and create it again.... Nope, same error... Let's check the number of connections on the MySQL server.... Nope, they are fine... The only thing I couldn't do or even try was restarting the MySQL server since it is shared by other users and applications. It was "very" frustrating. So after a couple of hours of trying different things, I fired up a terminal and tried this:


$ mysql -h  -u  -p

ERROR 1129 (HY000): Host '' is blocked because of many connection errors; 
unblock with 'mysqladmin flush-hosts'

Lo and behold, finally some light into the issue! The MySQL server was actually blocking my host from connecting to it. I imagine that this was because of the repeated errors while toying with the create dsn functionality. Anyway, after logging into the server from another host and running that command (mysqladmin flush-hosts) I was able to connect again with no problems. So there you have, if you see that error, it might be that your MySQL server is not liking you at the moment :)

BugLogHQ Updated - Always mind your charset!

Mon, 27 Sep 2010 15:23:00 -0000

I just posted to RIAForge an update to the BugLogHQ bug agregator, percolator and assimilator. This is a small update that includes some bug fixes and contributions. The update can be found at http://bugloghq.riaforge.org/. Also on a related note, over the weekend at work (where we use BugLogHQ) we had a ton of bug reports in BugLog that could not be saved to the DB and remained on the queue. All of them had some weird errors while trying to save a text column to the DB. All the errors where something along the lines of:


Incorrect string value: '\xE3\x82\xBD\xE3\x83\xAA...' for column 'HTMLReport'

After googling a bit, it turned out that it was a character encoding issue (the bug reports were coming from a site that could display Japanese content). After looking at the DB I saw that all the BugLogHQ tables where using the "Latin1" charset. After changing the charset to utf8 and the collating to utf8_unicode_ci, the problem went away and the entries were successfully saved to the DB. So as a precaution, in this update the SQL script to create the required tables now set the charset and collating correctly. However if you are experiencing this problem just change the charset and collating in your db tables to fix it. For MySQL you can do this in the command line with something like this:


ALTER TABLE `bl_Entry` CHANGE `HTMLReport` longtext CHARACTER SET utf8 COLLATE utf8_bin;

And repeat for any other table/column that is giving you problems.

Version 3.1.570 Released

Thu, 15 Apr 2010 18:46:00 -0000

The new update for HomePortals is now released. The current version is 3.1.570; This is a roll up of all the latest bug fixes since the last release. If you use the nightly build then you will not notice any difference right now. The full post about what is new/fixed on this release is here: http://www.homeportals.net/blog/index.cfm/2010/4/15/Version-31570-Released All comments are welcome!

Introducing the New HomePortals CMS Plugin

Mon, 01 Mar 2010 00:09:00 -0000

A few days ago I released the latest update to the HomePortals framework and its counterpart management platform ColdBricks. Besides the obligatory bug fixes and improvements, there was one new major feature on this release: the CMS Plugin. The CMS Plugin is a HomePortals extension to provide content management and site administration features to any HomePortals-based application without requiring the use of an external application (like ColdBricks) or building your own administration features. [More]

Available Update for HomePortals and ColdBricks

Wed, 24 Feb 2010 17:35:00 -0000

I just pushed new updated versions of HomePortals and ColdBricks to their respective sites and are now available for download. As usual the updates contain multiple bug fixes and small improvements here and there. However there are a couple of features that are worth mentioning. [More]

Update to 'Core' Framework. Now in GitHub!

Wed, 10 Feb 2010 03:31:00 -0000

A while ago I shared a small framework I created which I use to develop pretty much all of my projects (both open source and paid engagements). The framework, as is usual for web frameworks, follows the MVC and Front Controller patterns; also like Sean Corfield's FW/1 and Barney's FB3 Lite (and many others) it has an emphasis on minimalism and makes an effort to stay out of the way as much as possible. I recently made some changes to the framework and wanted to share them with the community. [More]

Model-Glue / HomePortals Sample Application

Tue, 17 Nov 2009 18:10:00 -0000

A few weeks ago I wrote about how to use the layout management features of HomePortals on a ColdBox 3 application. This time I want to show how to do the same but with an application built with the Model-Glue framework and also explain a bit more of why would you want to do so in the first place. [More]

miniwiki: a minimalist wiki

Mon, 02 Nov 2009 02:10:00 -0000

Miniwiki is a very basic and light wiki application for any CFML engine. Although it is designed to have a very small footprint, it can be easily customized in terms of skinning and layout. miniwiki uses a subset of reStructuredText as the syntax for the wiki pages, although it is trivially simple to replace the rendering mechanism to use WikiMedia syntax using the WikiConverter project. miniwiki uses HomePortals as the layout engine and also to manage and store the content. miniwiki is entirely file-based, although since it uses HomePortals resource libraries to store content you can also make it store content in something more exotic as Amazon S3. Here is a demo, and you can download the project from RIAForge here.

HomePortals/ColdBox Integration Revisited

Fri, 30 Oct 2009 14:50:00 -0000

A while ago I wrote a post about how to integrate the HomePortals layout rendering features into an a ColdBox application. Since then a lot has changed on both the HomePortals and ColdBox camps so I've been wanting to revisit that experiment and see if it could be made in an easier way now, using the advances on both frameworks. Read on for the findings. [More]

ColdBricks 1.1 Update: Custom Resource Libraries & Extension Modules

Tue, 27 Oct 2009 17:57:00 -0000

A new update to ColdBricks CMS is now available for everyone to download and play. This is still part of the greater 1.1 release but it adds some new interesting features that I thought would be interesting to blog about. Besides the obligatory bug fixes/performance enhancements, the two most prominent features are Custom Resource Libraries and the completion of a full modular architecture, including the option to install/uninstall modules directly by the end user. [More]

Got Bugs? There's An App For That!

Thu, 15 Oct 2009 21:20:00 -0000

Ever wanted to check up on your trusty BugLogHQ server to see whats going on with your apps on the go? Have an iPhone or iPod Touch? Well, today is your lucky day. I just pushed an update to BugLogHQ to include a custom web interface for the iPhone and iPod Touch. Even better, you can bookmark the app and add it to your Home screen and it will behave like a normal 'App Store' application. [More]

CFShell 0.2: Even More CLI Goodness for CFML Servers

Fri, 09 Oct 2009 01:13:00 -0000

Today I uploaded to RIAForge an update to CFShell. This update focused on making the client behave more like a standard command line tool, and also added a couple of useful commands and shorthand expressions to the shell. [More]

CFShell: A command line interface for CFML engines

Wed, 07 Oct 2009 17:21:00 -0000

Many times when we are working on our ColdFusion apps there are situations in which we want to quickly evaluate something or try some one or two-liner snippets to do something quick. The typical process then is that we have to create a .cfm page, put in on the server, go to the browser and execute it. And that's pretty much the only way we have for interacting with the CFML engine. This contrasts with other languages like Ruby, Python, or even PHP in which you can quickly interact with the language directly from a command line or terminal window. Wouldn't it be nicer to have the inmmediate satisfaction of evaluating our CFML/cfscript statements interactively? Well, that's where CFShell comes in. [More]