Tag Archives: databases

Redis: running Master-Slave replication in Kubernetes

29 September 2020
 

 The task is to spin up a Redis instance in a Kubernetes cluster. Will use the Master-Slave replication setup with Sentinels for monitoring and failover operations. Check the Redis: replication, part 2 – Master-Slave replication, and Redis Sentinel post for more details. Redis cluster vs Redis replication See Redis: replication, part 1 – an overview.… Read More »

Redis: “psync scheduled to be closed ASAP for overcoming of output buffer limits” and the client-output-buffer-limit

26 February 2020
 

 We have a Redis-cluster with Master-slave replication and Sentinel, see the Redis: replication, part 2 – Master-Slave replication, and Redis Sentinel, Redis: fork – Cannot allocate memory, Linux, virtual memory and vm.overcommit_memory, and Redis: main configuration parameters and performance tuning overview posts. The system worked great until we started using it much more actively. Redis… Read More »

AWS: Redshift – quick start and SQL-workbench connection config

18 October 2019
 

 Our data-analytics team eventually started to play with an AWS Redshift cluster instead of the MariaDB RDS service. Actually, the current task is to spin up a simple Proof of Concept Redshift’s cluster in the AWS. Let’s do it quickly, without details – if this will go to the Production, I’ll add another post with… Read More »

PostgreSQL: FATAL: Peer authentication failed for user “name”

11 September 2019
 

 A quick note mainly for myself on how to enable remote access in PostgreSQL and create its database dump. An EC2-server moved to our AWS account with one website. During an attempt to connect to the PostgreSQL running on this host – the “FATAL: Peer authentication failed for user “name”” appears. And the same error… Read More »

Redis: main configuration parameters and performance tuning overview

10 September 2019
 

 Currently configuring Redis server as our backend caching service and during that wrote this post with some things to pay attention at in Redis config file. Shortly enough but with links to other posts or documentation. Let’s begin with the redis-benchmark utility. Will be installed alongside with Redis service, so can be used right after… Read More »

AWS: MariaDB RDS – kill: You are not owner of thread

14 May 2019
 

 We have AWS RDS with MariaDB. The error below and its solution aren’t specific to AWS RDS and MariaDB. The next error appears during attempt to kill() a thread in MySQL: The solution is to use the mysql.rds_kill() procedure instead: Execute it: For Azure MySQL, there is a similar procedure mysql.az_kill(). Done.

Redis: replication, part 4 – writing an Ansible role fore the Master-Slave replication with Redis Sentinel provisioning

15 April 2019
 

 The next post from the Redis replication series. Previous parts: Redis: replication, part 1 – an overview. Replication vs Sharding. Sentinel vs Cluster. Redis topology. Redis: replication, part 2 – Master-Slave replication, and Redis Sentinel Redis: replication, part 3 – redis-py and work with Redis Sentinel from Python The task now is to write an… Read More »