Question:- Explain is it possible to replace Nginx errors like 502 error with 503?
Answer:- 502= Bad gateway 503= Server overloaded
Question:- In Nginx, explain how you can keep double slashes in URLs?
Answer:- To keep double slashes in URLs you have to use merge_slashes_off; Syntax: merge_slashes [on/off] Default: merge_slashes on Context: http, server
Question:- Explain what is ngx_http_upstream_module is used for?
Answer:- The ngx_http_upstream_module is used to define groups of servers that can reference by the fastcgi pass, proxy pass, uwsgi pass, memcached pass and scgi pass directives.
Question:- Explain what is C10K problem?
Answer:- C10K problem is referred for the network socket unable to handle a large number of client (10,000) at the same time.
Question:- Mention what is the use of stub_status and sub_filter directives?
Answer:- • Stub_status directive: This directive is used to know the current status of Nginx like current active connection, total connection accepted and handled current number of read/write/wait connection • Sub_filter directive: It is used to search and replace the content in response, and quick fix for stale data
Question:- Explain does Nginx support compress the request to the upstream?
Answer:- You can compress the request to the upstream by using the Nginx module gunzip. The gunzip module is a filter that decompresses responses with “Content Encoding: gzip” for clients or servers that do not support “gzip” encoding method.
Question:- Explain how you can get the current time in Nginx?
Answer:- To get the current time in Nginx, you have to use variables from SSI module, $date_gmt and $date_local. Proxy_set_header THE-TIME $date_gmt;
Question:- Explain what is the purpose of –s with Nginx Server?
Answer:- To run the executable file of Nginx –s parameter is used.
Question:- Explain how to add modules in Nginx Server?
Answer:- During the compilation process, Nginx modules must be selected as such run-time selection of modules is not supported by Nginx.
Question:- What is Redis?
Answer:- Redis is an advanced key-value data store and cache. It has is also referred to as a data structure server as such the keys not only contains strings, but also hashes, sets, lists, and sorted sets. Companies using Redis includes StackOverflow, Twitter, Github, etc.
Question:- Explain the Replication feature of Redis?
Answer:- Redis supports simple master to slave replication. When a relationship is established, data from the master is transferred to the slave. Once this is done, all changes to the master
Question:- What are the advantages of using Redis?
Answer:- Advantage of using Redis are • It provides high speed • It supports a server-side locking • It has got lots of client lib • It has got command level Atomic Operation (tx operation)
Question:- What are the limitations of Redis?
Answer:- • It is single threaded • It has got limited client support for consistent hashing • It has significant overhead for persistence • It is not deployed widely
Question:- List out the operation keys of Redis?
Answer:- Operation keys of Redis include • TYPE key • TTL key • KEYS pattern • EXPIRE key seconds • EXPIREAT key timestamp • EXISTS key • DEL key