AWS (Amazon Web Services) is a leading Cloud services provider. The product (service) offerings from AWS are enormous. For newbies, it may be difficult to understand what each Service is used for. In this short article I will give you a high level overview of the various AWS Services.
Instead of typing pages of information, I’ve compiled and distilled the core information and presented here in a tabular format. In this way, it can also act as a quick reference.
Occasionally you will want to know how many lines are there in a file. In unix world, you can use the nifty ‘wc’ command
wc –l < filename>
In Windows Powershell you can use the built in cmdlet named ‘measure-object’. It is pretty powerful.
For counting lines in a file, use the following command
Get-content <filename> | Measure-Object –Line
If you want to learn more about measure-object,
Help Measure-Object –detailed
If you come from the unix world, there is a nifty command you can use to ‘sleep’ in shell scripts. What about windows powershell?
You can use the command start-sleep just like you use ‘sleep’ in unix.
You can use either seconds or milliseconds as shown below:
I am sure you have gone through this: You see an interesting article in a website and decide to print it to take a closer look. The article itself is about a page or two in length. But what happens when you go to the printer to collect it? That’s right. It prints pages and pages of data, mostly ads and even more annoying – blank pages.
With Chrome, there is a neat feature that lets you avoid those annoying ads and blank lines.
Check this out. Here is a sample page that you see online:
Now when you print this article (either using Ctrl-P or using the chrome menu to choose ‘print’, you will see the following page
Buckle up! You can get your own AWS server in cloud. You can run a verity of OS on it, connect to any popular Database you want to and even get your hands on some of the coolest products from AWS. I don’t know about you but I’m psyched about all this.
Yes, Amazon Web Services Free Tier allows you to have your own Server in EC2 for 12 months. If you are new to AWS, this is a great way to get your feet wet, or may be drenched.
This article shows exactly how you sign up and crank up your own server in cloud. It takes about 15 to 20 minutes to get your hands on a brand new Amazon Linux instance (or Windows or Suse or RHEL…..)
Without further due, here are the actual steps to follow.
Analyzing logs can be fun, tricky, frustrating and valuable – all at the same time. As a problem solver, you must equip yourself with efficient tools to do the mundane work. In this article, let me show you three somewhat less popular log analysis tools. They are less popular because they are sparingly used by companies here and there (mainly due to Administrators becoming familiar with a certain tool over time). Check these out, who knows you might end up liking one of these tools and put it to good use.
Apache log4j is the foundation for java based applications. Chanisaw was written to provide a graphical view of log4j logs.
Image source: http://logging.apache.org/chainsaw/
Some notable features:
You can use expression based filtering and also do some quick-and-dirty filtering
Specify your own rules to highlight log records
Capturing remote events
Using the ‘Receiver’ concept you can configure chainsaw to capture logs from a remote source
Java memory leaks can be deadly, and difficult to troubleshoot. Are you one of those shops where you restart your Application Servers at regular intervals (weekly, daily or more frequently)? It is pathetic, is it not? Wait a minute, gone are the days where we had 128 MB memory on servers. We have several giga bytes of memory on servers, don’t we? Why do we still run into memory issues? Good question. But sad truth is there are several reasons why Memory leak is not something that will go away. All you can do is to prepare yourself. And that’s what this article is about. Let’s dive into 10 things you need to know about Java memory leak.
1. Java Heap Memory leak is different from Native Memory leak
Java heap is where the objects created by your application live. The maximum heap is determined by the –Xmx flag of the Java command line that starts the application. If you write code that leaks memory, there is where it will blow up.
Custom Dashboard is one of the most powerful features of AppDynamics. It lets you group monitoring metrics that are relevant (and make sense to the user) in one central dashboard. Custom Dashboards are ‘read only’ elements. So, you don’t have to worry about users updating any Appdynamics configuration. You can build sophisticated dashboards with drill down capabilities.
To create a new custom dashboard, click on the icon at the top and choose ‘Custom Dashboards’ as shown below
In the resulting screen, click on ‘Create Dashboard’
Agent is a vital part of Appdynamics framework. It is the agent that acts like a workhorse to pull metrics from the Application and push it to the Controller. Agent is a piece of software that is installed ON your application. The only function of the agent is to pull the monitoring metrics and send them to the AppDynamics Controller where the data is crunched and made available via the Controller UI. Note that there is NO need of a code change in your application. There is however a setup/configuration change required depending on the platform. In this article, I will explain how to instrument a Java Application.
At times you may want to find out which jar files are loaded by your Application. It is especially useful if you are dealing with classes present in multiple jar files and causing ClassCast exceptions. It is also useful if you are receiving ClassNotFound error and want to ensure the jar file that has the class file is loaded by your application.
There are few ways to do this.