Skip to main content

Data Replication: DevOps pre-state learning


Master-Slave

The master-slave is a database architecture divided into a master database and slave databases. The slave database serves as the backup for the master database. The master database is used for the write operations, while read operations may be spread on multiple slave databases.


Peer-to-Peer

Peer-to-peer replication provides a scale-out and high-availability solution by maintaining copies of data across multiple server instances, also referred to as nodes. Built on the foundation of transactional replication, peer-to-peer replication propagates transactionally consistent changes in near real-time


Synchronous

Synchronous replication ensures that when a disk IO operation is initiated by an application or the file system cache on the primary server, the system waits for IO acknowledgments from both the local disk and the secondary server before acknowledging the operation to the application or file system cache. This mechanism guarantees data consistency and is crucial for the failover of transactional applications when transactions are committed.


Asynchronous

Asynchronous replication involves placing input/output (IO) operations in a queue on the primary server. The primary server does not wait for acknowledgments from the secondary server before proceeding. Consequently, any data that has not been successfully copied to the secondary server before a failure of the primary server is lost.


Data Consistency

Consistency refers to the correctness & presence of the most recently updated data at any given moment in the database. The idea of having all-time access to purely consistent data is at the core of every relational database, it helps in maintaining the data integrity & accuracy as well.


Replication Topologies

This topology is the route of replication data (message) transfer from server to server over the network. It involves a source location pushing data to a target location, whereas the target also acts as a source distributing the data out to multiple target locations. This is typically used to replicate data into a data warehouse and building individual data marts.


Log Shipping

Log shipping is a method used to maintain a standby copy of a database, typically for disaster recovery purposes. It involves automatically copying and restoring transaction logs from a primary database to one or more secondary databases, often located on different servers. By keeping the secondary databases in sync with the primary, log shipping provides a reliable failover solution in case of primary database failure.

Comments

Post a Comment

Popular posts from this blog

Poridhi: Stacks & Queues

  Stacks & Queues related problems: This collection of solutions tackles three classic problems often encountered in technical interviews and competitive programming. The Valid Parentheses problem checks whether a string has properly matched and ordered brackets using a stack. The Sliding Window Maximum efficiently finds the maximum value in every window of size k across an array using a deque, a popular sliding window pattern that ensures optimal performance. The Stock Span Problem simulates a real-world stock analysis scenario and calculates the number of consecutive days before today for which the stock price was less than or equal to today's, also utilizing a stack for efficient computation. These problems test understanding of stacks, queues, and sliding window techniques. ✅ Valid Parentheses def isValid ( s: str ) -> bool : stack = [] mapping = { ')' : '(' , '}' : '{' , ']' : '[' } for char in s: ...
Post a Comment
Read more

Data Recovery: DevOps pre-state learning

  Data Backup Data backup is the practice of copying data from a primary to a secondary location, to protect it in case of equipment failure, cyberattack, natural disaster or other data loss events. This can include documents, media files, configuration files, machine images, operating systems, and registry files. Essentially, any data that we want to preserve can be stored as backup data. Data Restore Data restore is the process of copying backup data from secondary storage and restoring it to its original location or a new location. A restore is performed to return data that has been lost, stolen or damaged to its original condition or to move data to a new location. Pilot Light A pilot light approach minimizes the ongoing cost of disaster recovery by minimizing the active resources, and simplifies recovery at the time of a disaster because the core infrastructure requirements are all in place. Warm Standby The warm standby approach involves ensuring that there is a scaled down, ...
Post a Comment
Read more

Poridhi: Basic Programming & Math

Basic Programming and math related problems: Extracting digits means breaking a number like 1234 into [1, 2, 3, 4], often using string conversion or modulo/division. Counting digits involves finding how many digits are in a number using length of a string or repeated division. Reversing an integer flips its digits (e.g., 123 becomes 321), with care for signs and 32-bit limits. A palindrome number reads the same forward and backward, often checked by comparing the original and reversed number. Armstrong numbers are those equal to the sum of their digits each raised to the number of digits, like 153 = 1³ + 5³ + 3³. To find the sum of all divisors of a number, loop through integers and check which divide the number without a remainder. Prime numbers are only divisible by 1 and themselves, and checking up to the square root is efficient. GCD, the greatest common divisor of two numbers, can be found using a simple loop or more efficiently with the Euclidean algorithm, which uses repeated mo...
Post a Comment
Read more