I wanted to let everyone know about a new tool that I found that has, coincidentally, been added to our Cool Tools list. It’s called Networx and it is a supremo wonderful tool for monitoring your bandwidth. Now, this tool has more features than I can list here so I will list some of my favorites and link to the site for this piece of software, and I urge you to go check it out. If for no other reason, check it out because it’s a FREE tool that looks and operates like it ought to cost a lot of money.
OK, first of all you can install it or just extract and run, how cool is that this thing is so tight and so well written that you can just run it without installing it, using it’s own SQLite database. You can use this to grab all of your network usage in order to get the total picture of total bandwidth consumption, but here is some of the cool stuff, you can break off your network buy things like an interface or a network subnet and/or IP address and monitor those pieces of your network as well if you want to track bandwidth usage separately. In one instance, I know of someone who set this up to monitor the bandwidth of each roommate on the same cable subnet in order to make sure that whoever was using the bandwidth, paid for the bandwidth. No more pointing fingers and saying it’s all those streaming videos you watch and there really being no way to know. Now you can, and it’s really easy to setup. The reports it generates are way cool, the data can be exported to Excel and other standard output formats for even more tinkering, this thing has it all. And did I mention that it is totally FREE???
What are you freaking waiting for, go check it out, download it and use it, it’s awesome!!! While you are there, check out some of their other products (most of them are FREE!!).
*Note: Please remember that this is not any kind of paid advertisement or review. I am posting this because of exactly what I said in the article, I found this tool and found it to be useful and wanted to share it with my readers. I just want to make sure that you know that I in no way am getting paid for this article, nor do I get paid if you buy anything from the software vendor, etc. This is a 100% honest review from a happy user!
Just a quick note to let visitors know that I have updated the Must Have Firefox Extensions page in the Library, so feel free to check it out and see what we have down as the Firefox extensions that you have to have. Sure there are lots of others to get too, but you pretty much gotta get these to even get started! Thanks
If you spend any amount of time working with or administering UNIX and/or Linux servers, especially UNIX, you should be familiar with the text editor ‘vi’ and some commands like ‘sed’ and ‘awk’. If you have been around a while, or had the good(?) fortune of working on some old(er) systems, you might even remember the line editor ‘ed’. I’ll show my age here and recall fond memories of using ‘ed’ to write code many years back.
OK, on to the point, I was looking through Wikipedia for something entirely un-related, but ran across a tidbit of information that I thought was really cool, and that I knew I had to share with Solarum’s readers. It gives a bit of history about some of the tools that we use and love today.
“ed is a line editor for the Unix operating system. It was one of the first end-user programs hosted on the system and has been standard in Unix-based systems ever since. ed was originally written in PDP-11/20 assembler by Ken Thompson in 1971. Ken Thompson was very familiar with an earlier editor known as qed from University of California at Berkeley, Ken Thompson’s alma mater; he reimplemented qed on the CTSS and Multics systems, so it is natural that he carried many features of qed forward into ed. Ken Thompson’s versions of qed were the first to implement regular expressions, an idea that had previously been formalized in a mathematical paper, which Ken Thompson had read. The implementation of regular expressions in ed is considerably less general than the implementation in qed.
ed went on to influence ex, which in turn spawned vi. The non-interactive Unix command grep was inspired by a common special use of qed and later ed, where the command g/re/p means globally search for the regular expression re and print the lines containing it. The Unix stream editor, sed implemented many of the scripting features of qed that were not supported by ed on Unix; sed, in turn, influenced the design of the programming language AWK, which in turn inspired aspects of Perl.”
It’s pretty cool how stuff flows and comes together. Who knew or would have thought that a couple simple commands or programs would turn into what we have today.
*Note: starnix refers to the combination of UNIX, Linux and any other ix/ux OS that we work with.
This post is for anyone out there running any Navicat database tools. The company, PremiumSoft, that makes the line of Navicat tools is probably best known for there incredible database administration tool, Navicat. That’s where I first found them. They make a database admin tool that can connect to MySQL, MS SQL Server, Oracle, SQLite and everything in between. Aside from being able to connect to just about anything that stores data, once connected you can do so many cool things with your databases in the name of database administration, that it would take me a week to create a post for it all. Besides, this post isn’t a commercial for Navicat, but I did have to share just how good this product is. Believe me, it is amazing, and now they have this really wicked data modelling tool that works hand in hand with the database admin tool. You need to see it to believe it. Check out their site [link], they have very good demos and lots of information about the products.
My apologies, I digress, the main purpose of my post was to inform any people already using Navicat or any of the other PremiumSoft products about a problem I ran into and a way to fix it. I am using the software with MySQL databases primarily, but I believe the principle of the fix will apply to any database and server out there, especially Linux.
Now, one of the really cool things about the database admin and data modeling tools is that they can connect to your database via a SSH (Secure Shell Port 22) tunnel, instead of the normal default and usually plain text method. For example, by default, when you connect to a MySQL server, the username and password you give to the server is sent in plain text, so anyone can read it. Any command you type on that database console is also sent in plain text, so anyone can read it. Think about the new user you just created for your new web hosting customer. What if their database username and password fell into the wrong hands. It might be bad, it might not, it might be localized just to that one customer/user which would be bad enough, but suppose they found an exploit and got root on your server. Now they have all of your data. Even if you don’t have any data that is secret, just the hassle alone, not to mention explaining all of this to your customer(s) make this a really bad day.
This isn’t usually a big concern if you are running the database on the same server as the web server (which is common practice in many hosting scenarios), and if your database tools are on the server like the MySQL command line tools and such. But what if you want to connect to the database from say, your PC? Like you would do if using a database admin tool like Navicat. You certainly don’t want all of the data that you will be sending back and forth to be in plain text, right? Well, now you don’t have to leave it in plain text! You can setup the connection in Navicat to connect to the Secure Shell server, which means you have an encrypted connection and not plain text. Then, you can use the SSH tunnel that was created to connect to the database server itself. What this means is that you use the SSH server to redirect your communications to the database server locally, so no one can see it. Just like you were sitting at the server itself.
I’ll run through it again real quick, see if this makes sense. The connection between your PC and the server running database is now encrypted and secure from prying eyes because instead of connecting to the database server directly, you are connecting to the Secure Shell server. It is now the Secure Shell server that takes your communication and hands it off to the database server internally, so it’s safe from anyone watching outside. It’s really cool, and just another reason I love the Navicat product so much. Not to mention Linux as well!
The problem that I found was this, when I created the link to the SSH server in order to talk to the MySQL server, it wouldn’t connect. I would get the connection to the SSH server, but when it then tried to talk to the database server, the database server kicked it out like no connection could be made. I tried connecting locally from the Linux console think that maybe I killed some MySQL process that listens for connections, but it was working fine. I tried it again and again but it just didn’t work. The error I was getting from Navicat was this:
2013 – Lost connection to MySQL server at ‘reading initial communication packet’, system error: 0
I did some digging and found a basic setting to check. This didn’t fix the problem, but I thought I would share it here since it has to be set in order for the tunnel to work:
- In the sshd config file (/etc/ssh/sshd.config) make sure that AllowTcpForwarding is enabled, because the default is disabled in most cases.
What I finally found to be causing the problem, was TCP_WRAPPERS. Naturally, in my hosts.allow file I had the IP address of my PC in there, so that I could connect to the server. So at first this seemed odd that this was my problem. However, when you think about it, it makes sense. The connection that is coming to the MySQL server originates not from my PC, but from the SSH server itself. That’s right, because my connection stops at the SSH server, and then the SSH server sends the data to the database server. This is a simplified view of things, but it should work to illustrate what’s going on. Therefore, the simple fix was to add mysqld: localhost or 127.0.0.1 to the hosts.allow file in order to allow the traffic to go through TCP_WRAPPERS and to the MySQL server. I read more about this once I worked it out, and I saw some “technicians” offering the solution of adding mysqld: ALL to their hosts.allow file. Egads! I said! Technically that would work, but damn, don’t open it up to allow everyone into your databases!!! Just add localhost or 127.0.0.1 and you will be fine, and you will keep out the other riff raff. I hope this helps some of you out there, enjoy!
That title sounds pretty cool doesn’t it? Yes, it sure does! I found this nifty little tool and saw right away that I just had to share it with everyone. It’s a really cool web interface to a tool that lets you point and click your release information as well as your resource/branch preferences, and then BLAMMO, a new source list is made, just right for your Debian or Ubuntu box! In case someone reading this doesn’t know what a source list is, in Debian (and releases based on Debian, like Ubuntu) it is the file that tells the package manager (apt, dpkg, aptitude, etc) where to look for software you want to install, upgrade, and maintain automatically. The file name is:
Having a good source file can go a long way towards helping with easy and simple system administration. The URL for the site is:
http://debgen.simplylinux.ch/ for the Debian Generator and
http://repogen.simplylinux.ch/ for the Ubuntu Generator
So, go check it out and see what you think. I thought it was really cool and I got some good information from it.
Just a quick post to share something cool. I was learning more about the difference between classes and ID’s in CSS and found a great article at CSS-Tricks and I just had to share it with everyone. The link is here http://css-tricks.com/the-difference-between-id-and-class/ so go check it out if that sounds like something of benefit to you. The author goes way beyond just the differences, and explains many extra tidbits as well, a good and informative article all the way around. Hope this helps! Thanks.