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Installl MongoDB Create a custom YUM repository: sudo tee /etc/yum.repos.d/mongodb.repo <<EOF [mongodb-org] name=MongoDB Repository baseurl=https://mirrors.aliyun.com/mongodb/yum/redhat/7/mongodb-org/4.2/x86_64/ gpgcheck=1 enabled=1 gpgkey=https://www.mongodb.org/static/pgp/server-4.2.asc EOF Install the MongoDB package: sudo yum install ...

Delayed Replication Delayed replication introduces a lag in the SQL thread execution after data is written to the relay log. Recommended delay is typically 3-6 hours, depending on operational response time requirements. Key benefits: Mitigates physical corruption risks Standard replication doesn't address logical corruption Configuration (exe ...

How MySQL Master-Slave Replication Works When deploying MySQL in production environments, a single database instance often falls short in terms of reliability, availability, and scalability. The standard approach involves using master-slave replication to synchronize data across multiple servers, combined with read-write separation through a pr ...

Master Server Installation and Configuration To begin deploying the MooseFS (MFS) cluster, the Master server must be set up first. It is recommended to configure a network alias for high availability, though not strictly required for basic functionality. First, install the necessary dependencies and create the system user: yum install zlib-deve ...

Understanding Redis Performance Redis is renowned for its exceptional speed, a characteristic derived from several fundamental design choices: In-Memory Operation: As a memory-based data store, Redis inherently benefits from the much faster read and write speeds of RAM compared to disk I/O. Optimized Data Structures: It leverages highly effici ...

Setting up a highly available load balancing cluster requires two primary components: HAProxy for traffic distribution and Keepalived for failover management. This setup uses two virtual machines running CentOS 7.Environment PreparationInstall the EPEL repository and required packages on both nodes:yum install -y epel-release yum install -y hap ...

The Nature of Split-Brain in Distributed Systems Split-brain occurs when a network partition isolates nodes within a distributed cluster, causing them to form separate, disconnected sub-clusters. In a Redis environment, this often results in multiple nodes simultaneous believing they are the master. This scenario violates data consistency guara ...

Distributed System Fundamentals A distributed system consists of multiple independent computers communicating via a network to accomplish shared objectives. These systems lack a global clock and exhibit non-deterministic behavior among components located across different physical machines. Key System Properties Scalability enables horizontal ex ...

Starting the Service and Enabling Auto-Start On lb01: [root@lb01 nginx]# systemctl start keepalived.service [root@lb01 nginx]# systemctl enable keepalived.service On lb02: [root@lb02 ~]# systemctl start keepalived.service [root@lb02 ~]# systemctl enable keepalived.service Packet Capture Analysis with Wireshark Once the service is running, cap ...

Redis master-slave replication enables data from one Redis server (the master) to be copied to one or more other Redis servers (slaves). Data flows unidirectionallly—from master to slave. By default, every Redis instance starts as a master. A master can have multiple slaves, but each slave can only replicate from a single master. Key Benefits o ...