Collectd server not writing down received client data - linux

I have pretty strange problem with Collectd. I'm not new to Collectd, was using it for a long time on CentOS based boxes, but now we have Ubuntu TLS 12.04 boxes, and I have really strange issue.
So, using version 5.2 on Ubuntu 12.04 TLS. Two boxes residing on Rackspace (maybe important, but I'm not sure). Network plugin configured using two local IPs, without any firewall in between and without any security (just to try to set simple client server scenario).
On both servers collectd writes in configured folders as it should write, but on server machine it doesn't write data received from client.
Troubleshooted with tcpdump, and I can clearly see UDP traffic and collectd data, including hostname and plugin names from my client machine, received on server, but they are not flushed to appropriate folder (configured by collectd) ever. Also running everything as root user, to avoid troubleshooting permissions.
Anyone has any idea or similar experience with this? Or maybe some idea what could I do for troubleshooting this beside trying to crawl internet (I think I clicked on every sensible link Google gave me in last two days) and checking network layer (which looks fine)?
And just small note: exactly the same happened with official 4.10.2 version from Ubuntu's repo. After trying to troubleshoot it for hours moved to upgrade to version five.

I'd suggest trying out the quite generic troubleshooting procedure based on the csv and logfile plugins, as described in this answer. As everything seems to be fine locally, follow this procedure on the server, activating only the network plugin (in addition to logfile, csv and possibly rrdtool).

So after no way of fixing this, I upgraded my Ubuntu to 12.04.2 LTS (3.2.0-24-virtual) and this just started working fine, without any intervention.

Related

Node Can't connect to vagrant box

I am not sure if this is the correct place to ask my question, but really I am out of ideas, and my clock is ticking.
In short, I got a new machine that I need to make development ready.
This project is based on rather old program versions, that is a task to update.
In short I have set up the Vagrant (1.8.1) in VirtualBox (5.0.14). Chef (0.10.0) created all dependencies successfully and I can SSH to machine and see all is fine, all services are running as set in VagrantFile.
Vagrant box is latest ubunty/trystu64. My host machine is MacOs HighSierra(10.13.3).
Now, I open for example an mySQL editor (mySQL Workbench) and it connects to the Box, I can see DB and manipulate it.
My problem is with the NodeJS (I think). When I run my tests, it simply refuses to connect to the Box. More precisely, it attempts to connect to 127.0.0.1: 3306 (mySQL) and it errors. While MySQL Workbench performs the same connection without problems.
It seems the port forwarding in Vegrant works fine, as mySQL workbench is being forwarded to a box. Nodejs is not being forwarded, or something.
Is it Node doing it? Something else that I need to allow?
I have tried many different things, I have lost count. And always the same issue.
Is there something that I can do to Node, so it behaves as mySQL Workbench? Any idea is appreciated.
This identical setup used to work before, but not now.

Connecting to Firebird on Linux from a CGI application under Apache gives permissions error

I'm writing a small program in Free Pascal on Linux and connecting to a Firebird database on the same server. For testing, I initially wrote a console application using the TIBConnection components in FP and successfully connected to the Firebird database and listed records from one of the tables.
Now I'm wanting to do the same thing from a CGI application under Apache. A sample CGI app with various parameters displays different HTML results via the WebBroker "actions" like expected.
So both preliminary tests, connecting to Firebird and getting a CGI web app running, have worked. The final test is to combine them and that's where my problem is.
Whenever I run the test cgi application and try to connect to the Firebird database, I get a "permission denied" error. I've left the username, password, and port all at defaults, have checked the firewall, switched between "localhost" and "127.0.0.1" and several other things including setting the permissions on the database file to read/write globally (for temporary testing, of course).
I've found lots of information on the internet about connecting to Firebird on Linux and lots of information about writing CGI applications, but very little where it combines the two subjects. I'm sure there's a subtle yet important security or firewall issue, but it eludes me.
CentOS 6.6 64-bit on a virtual machine
Firebird 2.1.7 64-bit
Lazarus 1.4.0 64-bit
Anyone have any suggestions on what I could try?
I figured out how to get it working by reading the solution to a different problem. Not sure why disabling the firewall didn't work (I had to completely uninstall it) and don't know what SELinux is yet (had to set it to "permissive"), but I will need to study those two issues so the live server won't be left vulnerable.

Cannot access websites on apache from outside the server

I have a debian 7.5 based Ubuntu server, apache 2.2.22.
It's a rather vanilla installed XAMP used as a basic web server.
It used to work fine and I have no idea why it stopped working suddenly (there was some maintenance today but it worked when I left it - I changed partition sizes with Gparted).
When I try to access a website from the server (tried with w3m) all is working OK, including PHP and MySQL access.
When I try to access the same host (using a domain) from the outside, the browser keeps loading for a long while, eventually (after few minutes) saying the page could not be loaded.
I made sure that ports are open and accessible with outside scanner.
So I'm sure the Apache is available (working from inside the network, websites loading from SSH using w3M and pinging)
I'm sure the server is connected to the web (I can use putty to SSH)
the host is resolving to the correct IP (but won't ping from outside, only inside)
The ports seems to be opened (scanned and got OK for port 80)
I'm not a professional IT, so If there is info I can add that could help just ask away.
would really appreciate any idea or direction.
Thanks!
I still suspect the UFW/iptables firewall is blocking all incoming connections... Please go through this article and double check
http://www.cyberciti.biz/faq/ubuntu-server-disable-firewall/
If you're sure that the firewall config is OK, please try packet capturing with Wireshark to see what's going on underneath.
http://www.youtube.com/watch?v=sOTCRqa8U9Y How to install
Thanks for the help,
Oddly enough - It just started working again after 12 hours of not working.
A friend of mine, an IT person just called to try and help, and he simply connected (5 mins after I tried) and said it's all working for him.
I tried, and it's working for me also.
Have no idea why it stopped working, and why it is working now.
I think it might be an ISP problem or a router issue... The server is in our offices so I guess it could be both. I just don't understand why SSH would work and HTTP wouldn't.

Install Neo4j on Azure, cannot browse WebAdmin

I've just installed Neo4j 1.8.2 onto Azure by following this step-by-step process...
http://de.slideshare.net/neo4j/neo4j-on-azure-step-by-step-22598695
Unfortunately, when I browse to http://:7474/webadmin Fiddler says Error 10061 - No connection could be made because the target machine actively refused it.
I've followed the instructions exactly and haven't received any errors.
Any help much appreciated.
So, I think I got to the bottom of this. I think it was due to the size of compute / VM I was creating. It looks like the problem is caused when running on Extra Small instances. I created a new installation using a Small instance and everything now works :).
Try setting the server to accept connections form all hosts, and maybe use a newer Neo4j, say 1.9.4
http://docs.neo4j.org/chunked/stable/security-server.html#_secure_the_port_and_remote_client_connection_accepts
The way the VM Depot image is set up, it's pre-configured to allow all hosts to connect, and the Neo4j server will auto-start. The only thing you need to take care of, when constructing your VM, is to open an Input Endpoint, with any public port you want (preferably 7474 to stay true to Neo4j) and internal port 7474.
Note that the UI changed a bit since the how-to was published: You can specify the endpoint as the last step before creating your virtual machine. Other than that, the instructions should be the same. And... once the VM is up and running (it'll take about 5-10 minutes), you just visit http://yourservicename.cloudapp.net:7474 and you should see the web admin. Note: this is not the same as your vm name. If you named your VM something like 'neo' then you do not want http://neo:7474 or http://neo.cloudapp.net:7474. You need to use your cloud service name (you had to create a name for the service when you deployed the VM.
I've deployed that image several times in demos, and just tried again right now to make sure nothing wonky happened. Worked perfectly.

Configuring Apache Tomcat to run PHP

I would like to start out by apologizing. I have very little knowledge in the areas of Linux and Servers. I have been asked at work to set up a Linux box running Apache Tomcat. The Server needs to be enabled to allow websockets. I managed to get Debian installed. During the installation it gave me the option to make it a web server, which I did. There are now some different folders and files that are named "apache" in the files system, so my guess is that I am in fact running Apache, but to be honest I'm not 100% sure, and if it is, I don't know if its Tomcat. I fumbled around a bit and figured out the IP address of the computer I installed on and tried going to that IP from another computer in the network and it worked. I was able to see the html file that I put in the /var/www folder on the host machine. I then went out and found a nice piece of code, someone was kind enough to share, that is suppose to test websockets capability but I cant seem to get it working. My thinking is that my server isn't allowing PHP to run. I came to this conclusion by testing. I took a web page from my other server, its written in PHP, that when opened will send a text to my phone. Its just a small piece of code that I used for testing. When I tried running it from the Linux server it wont run, meaning it wont send the text to my phone. So here I am. I realize I'm asking for a simple solution to a complex problem, but I'm under the gun so to speak. I have about a week to get this going, so I just don't have the time to really immerse my self in this stuff the way I would like to. My question in its simplest form is"How do I configure my server to run PHP?" Any help/advice would be greatly appreciated! Thank you all for your time and patience.
Have you tried running a simple PHP script like echo 'Hello World';??
If not then try, if it works then your PHP is up, but sockets are just not configured to use.
If it doesn't work then install Ubuntu, a simple newbie friendly interface for Linux, and then install LAMP, here its how to do it.
And don't panic.

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