Migrate WordPress to static website

What for Someone who I maintain website for realized the bill of a public cloud provider isn’t exactly as expected. The computing resource falls under “free tier” but the disk isn’t. And the cost of disk usage is the surprise. Second, WordPress does a good job building the initial website but requires a hosting EC2 … Read moreMigrate WordPress to static website

Free tools for application high availability

High availability can be implemented through server clustering and load balancing. Clustering can be supported by corosync and pacemaker. On the load balancing side, there are dedicated hardware such as F5 which is expensive. Alternatively, there are three common ways to achieve load balancing with application, Linux Virtual Server (LVS), Nginx and HA Proxy. LVS … Read moreFree tools for application high availability

Nginx as a reverse proxy for Nifi web UI and Kibana

Nginx can act as a application neutral proxy. One example is to front Nifi. The nifi default configuration provides an HTTP access point, specified in the following entries in nifi.properties: Nifi can provide secure port by commenting out the lines above and provide the followings: However, it does require configuring JKS keystore for Java, as … Read moreNginx as a reverse proxy for Nifi web UI and Kibana

Quick way to configure Rest API service

Working in IT, we sometimes want the customer to have an API to perform pre-defined activities on our servers. We are hoping to manage the activities in a script to control what can be done, allow customer or partner to perform the activities on their own. Restful API is a great way to simplify and … Read moreQuick way to configure Rest API service

Networking Basics 3 of 3 – common network protocols and technologies

The 5 layer TCP/IP model (or its more rigorously defined alternative OSI model) leads to a whole world of network protocols. Understanding these new protocols requires one to map it out agains the network layers (e.g. at Layer 4 whether it is TCP or UDP, etc) . VPN is a whole family of technologies with … Read moreNetworking Basics 3 of 3 – common network protocols and technologies

Networking basics 2 of 3 – Layer 4 and common network configurations

Transport Layer Transport Layer handles multiplexing & de-multiplexing through ports. Port is more or less a virtual concept. Source port is usually ephemeral. Two dominant protocols are TCP and UDP. TCP relies on acknowledgement. TCP control flags are SYN, ACK, FIN, URG, PSH, RST, ECE, CWR. TCP connection is established by 3-way handshake and torn … Read moreNetworking basics 2 of 3 – Layer 4 and common network configurations

Storage Nitty-Gritty 5 of 5 – Replication

Replication Terms PIT (point in time) replica – snapshot of the source at some specific timestamp;Continuous Replica – always in-sync with the production data;Recoverability – enables restoration of data from the replica to the source if data loss or corruption occurs;Restartability – enables restarting business operations using the replicas; Local Replication Use Case: Alternative source … Read moreStorage Nitty-Gritty 5 of 5 – Replication