Networking, Python, BigData and Linux

Following are the some advanced UNIX commands which i found very useful. DNS (Domain Name Service) host string Perform forward or reverse lookup on string dig @nameserver string Lookup string's host info from nameserver System Hardware Information grep -i memtotal /proc/meminfo Find total amount of RAM in the system dmidecode -q Display DMI/SMBIOS information cat /proc/cpuinfo Display CPU information egrep '(vmx|svm)' /proc/cpuinfo See if a processor supports hardware virtualization lspci -tv Display PCI information lsusb -tv Display USB information hdparm -i /dev/sda Display disk information for sda Quick HTML Editing Site Wide find . -type f -print -exec sed -i -e 's|X|Y|g' {} \; Replace all X's with Y's in all files this directory and below. perl -pi -w -e 's/X/Y/g;' *.txt Replace all X's with Y's in all files ending with *.txt find -name '*' | xargs grep 'string' Print filename and all lines containing &#

Well, i was asked a question(which was last one)  write a shell script which renames all *.txt files in a directory to *.sh ? Immediately, mv command came into my mind as it does in many peoples' mind.Then i wrote like: find . -name "*.txt" -exec mv *.txt *.sh {}\;  however this was wrong. He told me to explain how the above would work and i realized this was not correct. then i tried something else like: find . -name "*.txt" -exec ls {}\; | perl -e '`rename *.txt *.sh`' I wasn't pretty much sure that this would work.He told thats fine if i could  try without perl. I asked for some hints and he reminded me of xargs & sh.Then i tried like: find . -name "*.txt" -exec ls {}\;| xargs -n1 sh -c 'mv $1 `basename $1 .txt`.sh' - and then i got selected in the unix rounds... :-) :-)  xargs is really a great unix command like sed & awk.It is quite often used for parallel processing.Never miss this if you  like t

Well, this article doesn’t take you into any depth of management software solutions. However, this article gives a broad insight into the current industry trends in management software solutions. When we say a management system we are using very vague term in fact. There are many different management systems to achieve different goals. As per my knowledge so far the NMS software particularly meant to manage the devices from a single vender does have most of the FCAPS functionalities in it. Which means single software is used to achieve Configuration management, performance management, fault management & monitoring, Security management & Accounting management in few cases. However, the management software which supports multiple vendors may be different for different FCAPS functionalities. Suppose one software for Network monitoring for multiple vendor NEs(ex. EMC smarts), one for Configuration management for multiple vendor NEs(Ex. HP openView), one for performance man

An element management system (EMS) manages one or more of a specific type of telecommunications network element (NE). Typically, the EMS manages the functions and capabilities within each NE but does not manage the traffic between different NEs in the network. To support management of the traffic between itself and other NEs, the EMS communicates upward to higher-level network management systems (NMS) as described in the telecommunications management network (TMN) layered model. The EMS provides the foundation to implement TMN–layered operations support system (OSS) architectures that enable service providers to meet customer needs for rapid deployment of new services, as well as meeting stringent quality of service (QoS) requirements. As recommended by ITU-T, the Element Management System's key functions are divided into five key areas - Fault, Configuration, Accounting, Performance and Security (FCAPS). Portions of each of the FCAPS functionality fit into the TMN mode

Well, When the NMS/EMS server comes to halt at any point of time, how would you proceed with the analysis? As per my experience working on three different NMS product, i'd proceed with following steps: 1. Check the connectivity to NMS server using ping from client.     If this is OK, then go to next step.Else fix the network connectivity issue. 2. Login to the NMS server and check the NMS processes using ps -aef  | grep "name-of-nms-server.*"     If this is ok, then Go to next step.Else restart the NMS server. 3. Check the NMS log file and see if any errors in log file.     If this is ok, then go to next step.Else take the corrective actions according to the error information in log. 4. Check the firewall status using " service iptables status"     If Firewall is not running then go to next step.Else stop the firewall using "service iptables stop" 5. Check if  the /etc/hosts.conf file is corrupted     If /etc/hosts.conf file is correct then