Last updated 19/06/2020
Do you know how much you can earn from choosing a career as a Site Reliability Engineer?
It starts from $136,836 per year. Can you believe this?
Site Reliability Engineering is basically creating a bridge between Development and
Operations departments. It is a discipline that incorporates aspects of software engineering and applies them to infrastructure and operations problems. The main goals are to create scalable and highly reliable software systems.
The job role of a Site Reliability Engineer includes the following responsibilities:
Pretty interesting. Isn’t it? Well, the job interview of a Site Reliability Engineer, too, is pretty interesting!
Check out these 20 most commonly asked Site Reliability Engineering interview questions to get an idea about how interesting it actually can be!
Ans. A thread is a lightweight process. Each process has a separate stack, text, data, and heap. Threads have their own stack, but they share text, data, and heap with the process. Text is the actual program itself, data is the input to the program and heap is the memory that stores files, locks, sockets.
Ans. A zombie process is a one that has completed execution, however, it’s entry is still in the process table to allow the parent to read the child’s exit status. The reason the process is a zombie is that it is “dead” but not yet “reaped” by its parent. Parent processes normally issue the wait system call to read the child’s exit status whereupon the zombie is removed. The kill command does not work on the zombie process. When a child dies the parent receives a SIGCHLD signal.
Ans. Zombie processes are created when the parent does not reap the child. This can happen due to parents not executing the wait() system call after forking.
Ans. Following steps can help you daemonizing a process:
Ans. Some ways of process inter-communication are:
Ans. Signals are an inter-process communication method. The default signal in Linux is SIG-TERM. SIG-KILL cannot be ignored and causes an application to be forcefully killed. Use the ‘kill’ command to send signals to a process. Another popular signal is the ‘HUP’ signal which is used to ‘reset’ or ‘hang up’ applications.
Ans, TCP slow start is a congestion control algorithm that starts by increasing the TCP congestion window each time an ACK is received until an ACK is not received.
Ans. Few TCP connection states are:
1) LISTEN – Server is listening on a port, such as HTTP
2) SYNC-SENT – Sent a SYN request, waiting for a response
3) SYN-RECEIVED – (Server) Waiting for an ACK, occurs after sending an ACK from the server
4) ESTABLISHED – 3 way TCP handshake has completed
Ans. The protocol states of DHCP are:
An inode is a data structure in Unix that contains metadata about a file. Some of the items contained in an inode are:
2) owner (UID, GID)
4) atime, ctime, mtime
6) blocks list of where the data is
Ans. Http cookie is a small piece of data that a server sends to a browser, which a browser usually stores in its cookie cache. A cookie can be used to maintain session information since HTTP is stateless, and also for user preferences at a given site. Cookies can also be used to store an encrypted password. Browsers send cookies back to the server when they make a connection’
Ans. Some common HTTP response codes are:
Ans. Http methods are ways of communicating between server and client. Common examples are HTTP get and HTTP put which is used by HTTP forms for data exchange. Other methods include, post, head, and connect.
Ans. HTTP header fields are common components of HTTP requests and responses. Headers are colon-separated name-value pairs in cleartext. Some common headers are: Cache-control which specifies where to cache or not the contents of a page, Accept, which can be text/plain, Content-length which specifies the size of the content, Host, which is the domain name of the server.
Ans: Few common aspects of MyISAM is:
On the other hand, some known facts about InnoDB are:
Ans. Once you power a system on, the first thing that happens is the BIOS loads and performs POST or a power-on self-test, to ensure that the components needed for a boot are ok. For instance, if the CPU is defective, the system will give an error that the POST has failed. (BIOS stands for Basic Input/Output System)
After POST the BIOS looks at the MBR or master book record and executes the boot loader. In case of a Linux system that might be GRUB or Grand Unified Bootloader. GRUB’s job is to give you the choice of loading a Linux kernel or other OS that you may be running
Once you ask GRUB to load a kernel, usually an initial ramdisk kernel is loaded, which is a small kernel that understands the filesystem. This will in turn mount the filesystem and will start the Linux kernel from the filesystem
The kernel will then start to init, which is the very first process, usually having PID 1. Init will look at /etc/inittab and will switch to the default run-level which on Linux servers tends to be 3.
There are different run level scripts in /etc/rc.d/rc[0-6].d/ which are then executed based on the run level the system needs to be in.
And that’s about it!
Ans. SSL stands for secure socket layer. It has been renamed to TLS starting from SSL v 4.0. TLS is a secure way of communicating through a network. A majority of secure HTTP communication on the web takes place using TLS. TLS works at session layer and presentation layer of the OSI model. Initially at the session layer asymmetric encryption takes place, after that at the presentation later symmetric cipher and session key are used. The basic principle behind TLS is to encrypt data going across the network using public-key encryption first, followed by using a shared key. Also, the other component of TLS is server certificate authentication which is done through a certificate authority. Clients contain a list of certificate authorities, and it uses the public key of the CA in the certificate to verify the certificate being authentic.
Ans. One possible solution to get from source to destination using SSH dynamic tunnel, is to create a dynamic tunnel.
Ans. One option is to boot from the network using PXE or using a USB drive which has Unetbootin installed.
Once you start the installation, go to the main menu, select the ‘Start Installation’ option, choose ‘Network’ as the source, choose ‘HTTP’ as the protocol, enter ‘mirrors.kernel.org’ when prompted for a server, and enter ‘/centos/6/os/x86_64’ when asked for the folder.
From the above SRE interview questions and their answers, you must have understood that it is both the practical and theoretical knowledge that will help you to get through an SRE interview. Now how to achieve that? Pretty simple! Join our Site Reliability Engineering training and certification course, get trained, get certified, set the bar of your CV high, and Voila!
NovelVista Learning Solutions is a professionally managed training organization with specialization in certification courses. The core management team consists of highly qualified professionals with vast industry experience. NovelVista is an Accredited Training Organization (ATO) to conduct all levels of ITIL Courses. We also conduct training on DevOps, AWS Solution Architect associate, Prince2, MSP, CSM, Cloud Computing, Apache Hadoop, Six Sigma, ISO 20000/27000 & Agile Methodologies.
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