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The release of Sproutcore 1.10  marks an important step in the life of this very popular framework. Lots of new features make developing applications on the Sproutcore framework even easier and fun. One improvement that I am sure will catch your eye (pun intended) is  view animations . Coding view animations was rather easy also on previous versions, but with 1.10 animations are now first class citizens bolted into the core rendering subsystem. For an example of what is available out of the box see this  demo . So how would you use this goodness in an actual Sproutcore application? And how much code would it take? As an example I have put together a very basic Sproutcore app ( source , demo ) which has two states: an authentication form and a main screen. Logging in transitions the app from the login form to the main screen and logging out returns the app to the login screen. Pretty simple.

Just a quick note to self that to enable/disable/query event log registration from the command line on Windows releases greater than XP and Server 2003 you can use the wevutil tool. For example to enable logging of print requests on Windows 7 for auditing purposes: wevtutil sl Microsoft-Windows-PrintService/Operational /e:true The equivalent command for the the above on Windows XP is the following: reg add HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Print\Providers /v EventLog /t REG_DWORD /d 7 /f net stop spooler net start spooler

The Cloud9 online IDE running on Chrome/Mac. Today I was looking for a way to quickly edit a pull request to the Sproutcore project without booting up my laptop, but using the MacMini in the living room instead, which is always on, being our main entertainment system. Turns out it's quite easy if you do not mind signing in into another online service: the  Cloud9 online IDE .

Disclaimer: Packt kindly sent me a free copy for review. TL;DR: Rating 4/5. Recommended for beginners and intermediate. The book itself is short, but packed with information. A fast reader with some experience with OpenNMS should be able to finish it in 4 to 6 hours. Beginners will probably want to follow the pointers to the online documentation, check the configuration files and possibly experiment so they should allocate more time. Before being published the book has been reviewed by Jeff Gehlbach. Anyone who has been involved with OpenNMS for some time know him, as he is one of the many brilliant minds working for the OpenNMS company, the commercial entity which develops and supports OpenNMS. Surely his involvement serves as a kind of seal of quality for the book. I for one was surprised by the clarity with even the most complex aspects of OpenNMS were presented in such a short text. Instant OpenNMS Starter is divided in three main parts: installation, quick start...

Going beyond the normal application availability check One interesting use of the  OpenNMS JDBC poller is for extracting data from the Oracle administrative database tables, for example tracking tablespace quota usage to detect quota exhaustion, sudden usage peaks and graph usage over time. Graph of quota usage for user [redacted] on tablespace DAT. Notice the cleaning operation running at 3.30 AM Tablespace quotas is a feature present in the Oracle database that allows the DBA to set a limit on the amount of storage that any given user can consume on a specific tablespace. This allows the DBA to share tablespaces across users yet still be able to policy users into predefined usage boundaries. When a user consumes all its quota it can no longer store data, but it can delete it, thus allowing self-recovery.

Updated Oct 16 2013: shadow copies, memory settings and links for further learning. Updated Nov 15 2013: shadow copies example, samba tuning. Unless you've been living under a rock you should have by now heard many stories about how awesome ZFS is and the many ways it can help with saving your bacon . The downside is that ZFS is not available (natively) for Linux because the CDDL license under which it is released is incompatible with the GPL. Assuming you are not interested in converting to one of the many Illumos distributions or FreeBSD this guide might serve you as a starting point if you are attracted  by ZFS features but are reluctant to try it out on production systems. Basically in this post I note down both the tought process and the actual commands for implementing a fileserver for a small office. The fileserver will run as a virtual machine in a large ESXi host and use ZFS as the filesystem for shared data.

Being a longtime Java developer, back from when servlets where cool and Struts was making MVC popular among web devs, I always try to find new and more productive ways to deliver software within the Java ecosystem. Recently I turned to Grails and delivered several projects with it. When developing with Grails you can use the power and the expressiveness of Groovy to write compact, elegant, fluent and readable code. The downside is that Grails is huge: even the most simple Grails apps will weigh in the 40MB range compilation, test and building takes a long time (minutes, actually) even in recent versions it is (fairly) complex, but that I can understand because it does so much it will consume a huge chunk of you app server memory when deployed I have been using Grails as the backend for  Mappu  too, initially just because I wanted to bootstrap the project quickly and Grails is simply perfect for that. But as time passed I started to find Grails too heavy for a sim...

As a long time OpenNMS user I've been often impressed with its extensibility and the completeness of its feature set. There is support for lots of data collection techniques: from the old school snmp exec extensions, to the http poller, from the JDBC poller to the XML poller and many others  that I probably forgot to mention. Supporting new probes is therefore just a matter of how,  not  if  , it can be done. And with new monitoring tools popping up every day this is clearly good as it allows OpenNMS to keep up with the competition. So the present looks bright, but what about the future? With OpenNMS 2.0 not yet on the radar I thought I could put together a list of features I would love to have. What do you think of them?

A common problem with OpenNMS is how to monitor a log file and trigger alerts when certain conditions are met. Let me clarify with an example: you have this mission critical app that sometimes experiences internal errors. The application keeps running and still responds to requests, but the error will slow down the system and/or delay further processing. Monitoring the process and/or network polling will obviously not be able to detect the issue and the only way is to tail the application log file and look for certain messages. The problem can usually be solved simply by forwarding the log file to OpenNMS through syslog, but what for logs generated by applications that don't speak syslog or if you don't want to configure syslog forwarding?

Subtitle: broken by impress.js I've been using Linux as the primary OS on all my laptops since a loooong time ago and until recently I always chose computers fitted with nvidia graphics over any other brand because their drivers probably have the best quality and performance. My last (and current) laptop, an HP ProBook, came with ATI graphics, but since in the last years ATI seemed to have caught up, I decided to give it a try. For over two yeas the laptop performed extremely well with Ubuntu 10.04 LTS as everything worked right out of the box with no customization whatsoever. Suspend/resume worked, performance was great and boot time pretty good too (for a conventional hard drive at 7200rpm, at least). The problems came with the upgrade to Ubuntu 12.04.

It's that time of the year again and, since it appears that the Maya spared us, I want to share with you a couple of gists that I came up with recently that could be generally useful. Btw, there are lots of other gists on my gist.github.com profile, check them out. If you find these script useful star them on github, drop me a comment or just share them. Once again, Merry Christmas everyone! The first one is for Java people and is a HttpServletRequestWrapper that supports: injection of the principal: for those cases when you use trust authentication and you are rolling your own SSO solution and/or you need to integrate with an existing SSO solution (I used it with for CAS ) supports reading of the InputStream multiple times. We all know that in a POST the request input stream can only be read once, so this will definitely help you if you need to access the post body or a request parameter in a Filter and make sure the upstream servlets/filters still work

To improve the quality of both my sleep and Mappu development I have started using Selenium IDE for automated testing of Mappu's UI. It was kind of hard at the beginning, being the UI based on Sproutcore which has the annoying habit of changing the controls ids with every page load, but after a while I was able to get it rolling quite nicely. Then I hit a major roadblock: the OpenLayers-based map control wouldn't react to clicks, mousedown, mouseup, fireEvent or anything else I threw at it.

Grails has had a liquibase plugin for a long time (note: I am talking about the old liquibase plugin based on 1.9). One functionality that (I feel) it's missing is a proper Bootstrap hook so that database changes can be deployed right when the application starts. The newest liquibase plugin called  grails database migration  has it built in.

In enterprise environments VMware vSphere is the most common virtualization choice. Hence when it comes to provisioning most rely on vm templates to accelerate and standardize the creation of new virtual machines. While templates work well for both Windows and Linux vms it still leaves a lot out and administrators may have additional work that has to be carried out manually (like configure networking, optionally move the vm in the right network/resource group, create application accounts, set up IIS, tomcat, java, etc, etc). True, most of this post-bootstrap setup can be taken care of with Puppet, Chef or, in my case, Saltstack , but what I wanted was a push-button vm provisioning that does all of the following automagically: create a new vm (only Linux vms are supported as of now) assign a pre-determined static ip address/name move vm into appropriate network configure it with Saltstack register the vm into out monitoring system (currently OpenNMS )

Disclaimer: this is just a shameless post to get myself a place at the great Rome event ;-). Oh well, this does not mean this post is not interesting to read. When I went to the Extreme Programming conference in Alghero (Sardinia) in 2001 I was consulting mostly as a Systems Administrator. So I felt a little bit like a fish out of water and actually one of the participants asked me: do you think there are aspects of XP that can be applied to systems administration? I think I said yes, but at that time it was kind of hard for me to find points of contact between the two. Maybe unit testing could be associated with putting a pervasive monitoring in place so that when I refactored a configuration I would know if it worked before clients did. Or coding standards could be associated with using automated installers for deploying servers, but what about keeping the configuration in sync after, when the systems went into production? And what about the rest of the rules? Last bu...

See all my Salt-related posts Welcome back! In our quest to simplify the configuration and automate our systems we have  installed  Salt on all our servers and then moved on to some  basic state management . We want of course to do more sophisticated stuff with salt and we'll get to that too. But first we want to make sure that all minions are aligned to the same salt version (the latest in this case). To do that we will add another state to our configuration which we will call (very much unimaginatively) salt.sls. The content is below: salt-minion: pkg: - latest service: - running - watch: - pkg: salt-minion This instructs minions to upgrade the salt-minion package on the node and, if upgraded, restart the service. To activate this state we'll edit the top.sls state file as follows: base: '*': - ntp - salt We are now ready to apply the changes. Let's start with a guinea-pig minion: [prompt]# salt 'expendab...

Welcome to the third episode of the series ! In the previous posts we have installed salt on CentOS machines and then moved on with a basic state configuration (we will cover more in the coming postst). Now it's time to handle those pesky SLES hosts for which there are no pre built binaries. Therefore we'll have to install salt using pip . I'll cover SLES11 in this post as that's the only variant I have. Hopefully other versions should require only minor changes. Note: active subscription to Novell update service is required as the following packages can only be found on SLES 11 SDK (it's an iso, and a large one, so if you don't have it around start downloading it before you start):  python-devel libopenssl-devel zlib-devel swig Installation Add the SDK iso in the Software Management sources. Then, as root, run the following commands (answer yes when required): zypper in gcc-c++ python-devel libopenssl-devel zlib-devel swig zypper -p http://downlo...

I was recently asked to recover a mirth instance whose embedded database had grown to fill all available space so this is just a note-to-self kind of post. Btw: the recovery, depending on db size and disk speed, is going to take long. The problem A 1.8 Mirth Connect instance was started, then forgotten (well neglected, actually). The user also forgot to setup pruning so the messages filled the embedded Derby database until it grew to fill all the available space on the disk. The SO is linux. The solution First of all: free some disk space so that the database can be started in embedded mode from the cli. You can also copy the whole mirth install to another server if you cannot free space. Depending on db size you will need a corresponding amount of space: in my case a 5GB db required around 2GB to start, process logs and then store the temp files during shrinking. Then open a shell as the user that mirth runs as (you're not running it as root, are you?) and cd in...

After part 1  of this series I had Salt running properly on all minions. It's now time to get some work done with it. We will start with something simple like making sure that ntp is installed and running on all minions. In order to to do that we will use the Salt  states enforcement feature. The default salt states configuration requires that: state definitions be kept in  /srv/salt the default state be named top.sls We will probably need to create both the directory and the files, which we can do with the following command (check that you are not overwriting your own state, needs to be done on the master only!): mkdir -p /srv/salt cat <<EOF >/srv/salt/top.sls base: '*': - ntp EOF What this state definition means is that the base state requires all nodes (as selected by '*') to apply the ntp state. Since we have not yet defined an ntp state we are going to do it right away: cat <<EOF >/srv/salt/ntp.sls ntp: pkg: - ins...

This post is the first in a series documenting the deployment of Salt on a small network ( ~ 100 hosts, initially targeting only linux-based ones which account for roughly half of it). Due to the low number of hosts I have gone for a single master layout. The linux hosts are for the greatest part running Centos 5.[4,5] in both x86 and x64 favors, and just a couple running SLES. Installing salt master The easiest way to install salt on Centos is to pull in the epel repository  : rpm -Uvh http://download.fedoraproject.org/pub/epel/5/i386/epel-release-5-4.noarch.rpm then install salt with yum: yum install -y salt-master Since minions by default will attempt to connect to the salt master by resolving an host named  salt  I configured a salt cname record for the salt master host in the dns server. At this point the master can be started with: /etc/init.d/salt-master start Note : I don't have firewall or SELinux enabled. In particular SE...