Iterate through Cassandra table with DataStax Python Driver

In most Cassandra use cases a data table is hardly updated or deleted in prevention of tombstones. Versioned records are used to ensure only insertion is used on the table. The result is that Cassandra table is usually much longer than its cousin in relational database. Like it or not, full table scan is still … Read moreIterate through Cassandra table with DataStax Python Driver

Performance Analysis Tools

Basic Tools In 2015, Brendan Gregg posted two great articles on Netflix blog: Linux Performance Analysis in 60 seconds, and Linux Perfomrance Tools. They have great value when I was in a urgency to spot performance issues. The articles cover the essential tools for performance troubleshooting, including: Check out load averages: uptime or w Print … Read morePerformance Analysis Tools

Ansible at scale 2 of 2

Template (with Jinja2) and files In an Ansible role, we can use files or templates to achieve similar results for configuration files. If the configuration file is the same across all targets then we can place it in files directory to push out. If the content of configuration file varies depending on the cluster size, … Read moreAnsible at scale 2 of 2

Ansible at scale 1 of 2

Our original automation scheme involves several Ansible playbooks that started off simple but have been sprawling. So recently I spent some time to revamp the entire set of playbooks, following some of the best practices from the official documentation. The goal is to: Reduce the number of playbooks; Improve code re-usability (by implementing roles); Increase … Read moreAnsible at scale 1 of 2

Common local Git operations

This is a summary of concepts in common Git operations. We will discuss brach, merge, rebase, cherrypick, stash and reset. We will not discuss pull, fetch, or push. Commit, Branch and HEAD When you run “git commit”, the following happens: Git checksums each subdirectory, and stores them as a tree object (file path and name) … Read moreCommon local Git operations

Security Assertion Markup Language (SAML)

SAML is an XML-based standard for exchanging authentication and authorization data between IdP (identity provider) and service provider. We can compare SAML with LDAP (as authentication protocol) as both are to provide single-sign-on (SSO) feature. LDAP is considered traditional configuration in on-premise operation for organizations. The configuration can be complex and administrators needs to complete … Read moreSecurity Assertion Markup Language (SAML)