How to schedule weekdays only on Airflow

Consider the following situation: You have a data ingestion pipeline where the data comes in real-time on weekdays and is stored in a dated folder.  The day’s data needs to be ingested within four hours. An instant response may be…

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How to migrate data from Cassandra to Elassandra in Docker containers

A client recently asked us to migrate a Cassandra cluster running in Docker containers to Elassandra, with the data directory persisted via a bind mount. Elassandra is a fork of Cassandra integrated closely with Elasticsearch, to allow for a highly scalable…

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MySQL swapping with Fsync

One problem that’s a lot less common these days is swapping. Most of the issues that cause swapping with MySQL have been nailed down to several different key configuration points, either in the OS or MySQL, or issues like the…

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Interesting happenstance when installing Ansible dependencies in a MySQL Docker container

I’ve been posting quite a bit about Docker as I’ve been working with it a lot as of late. I thought I would share something interesting I discovered a couple weeks ago while working on setting up a Docker container-based…

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Orchestrator datacenter detection

Orchestrator is datacenter-aware, meaning that it takes nodes location into consideration when performing a topology change. Let’s explore the options to make Orchestrator automatically detect this configuration.   Using MySQL server One option is to use the monitored database server…

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HAProxy MySQL lag awareness via systemd

In one of the projects I have been working on, one requirement was the ability to stop traffic from reaching a MySQL host which has been lagging behind its master for longer than a specific amount of time and then…

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Cassandra backups using nodetool

Cassandra nodetool provides several types of commands to manage your Cassandra cluster. See my previous posts for an orientation to Cassandra nodetool and using nodetool to get Cassandra information. My colleague has provided an in-depth analysis of backup strategies in…

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Technical insights into CockroachDB

I recently had the pleasure of discussing CockroachDB on the Datascape Podcast with Chris Presley and I wanted to supplement that episode with a bit more technical information about this database. A deeper look at consensus CockroachDB uses the Raft…

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Priority in MongoDB replica sets

I had interesting use case with a MongoDB replica set I’d like to share. When the replica set consists of four nodes and the Primary goes down, no new node is elected to become the new Primary. The replica set…

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Backing up your MySQL instance physically with Docker

In a previous post I had mentioned that I was doing a bit of digging into Docker in order to get a better grasp of the technology. Part of that was exploring common administrative tasks. I would venture to say…

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