The first draft of DHCP was written in October 1993. Lets time travel and go to a time where there is no DHCP. Lets have a look at the why you need DHCP. It is very important as it provide the machines their identity to be on the network grid. DHCPD is a server for
In recent times, I was working with Redis clusters which have very high throughput. While doing this we came across a problem which was Redis bgsave was taking a lot of memory sometimes almost as the same memory as the data present in the memory. In this small writeup, we will see why this happened.
Recently while working with one of the databases I came across a method that is widely used by many databases to take a snapshot of the memory into a disk. One of the most famous that you have heard of is Redis. The method is called copy on write. Let’s see what is a copy
In this article, we are going to start learning system programming by first of all creating a copy program like cp using low-level IO functions and not the standard IO functions. Now first let’s see what is system programming and what is low-level IO functions in C. System Programming: System programming aims at producing software
BPF also known as Berkeley Packet Filters was introduced first in 1992 by Steven McCanne and Van Jacobson in their paper The BSD packet filter: A New architecture for user-level packet capture. In this paper, they presented about BPF architecture and how it interfaced with the rest of the system and a new mechanism for
Monitoring is very important when you want your systems to work properly. Monitoring helps you identify the issues while they are happening or before them. So it is very important to implement your monitoring properly. Let’s see what is black box monitoring. Now when you see any issue how you should approach your debugging. First
In linux environment when you run any piece of code, any application or software. The piece of code actually maps to the some set of instructions in kernel level. To see those instructions that are being executed for that piece of code we can use this tool called strace. We will see what system calls
Recently I came to know about the runlevels in linux while going through initd. So I thought of writing about it and here it is what are runlevels in linux systems? Run-levels are the mode in which you unix system boots up. These modes can be from single user with no networking to full fledge
Linux is a very powerful Operating system and it has many flavors. Its always your choice which one to use but making them work faster and according to your need is something you will need. Here we will talk about alias and write a simple alias file to help you be more productive.Lets see how
When it comes to servers it is really important to keep track of memory, cpu utilization, which processes are taking what amount of CPU, what process are orphan processes etc. All these are required to take necessary step like kill a process if it is taking a lot of CPU or trigger autoscaling when CPU
Interview preparation and questions for DevOps and SRE