Wednesday, August 16

Tag: streaming replication

Logical Replication in PostgreSQL 10

Petr's PlanetPostgreSQL
PostgreSQL 10 is getting close to its first beta release and it will include the initial support for logical replication, which is was written primarily by me and committed by my colleague Peter Eisentraut, and is internally based on the work 2ndQuadrant did on pglogical (even though the user interface is somewhat different). I'd like to share some overview of basics in this blog post. What's logical replication? Let me start with briefly mentioning what logical replication is and what's it good for. I expect that most people know the PostgreSQL streaming master-standby replication that has been part of PostgreSQL for years and is commonly used both for high availability and read scaling. So why add another replication mechanism and why call it logical? Well, the traditional (more…)
Evolution of Fault Tolerance in PostgreSQL: Synchronous Commit

Evolution of Fault Tolerance in PostgreSQL: Synchronous Commit

2ndQuadrant, Featured, Gulcin's PlanetPostgreSQL, PostgreSQL
PostgreSQL is an awesome project and it evolves at an amazing rate. We’ll focus on evolution of fault tolerance capabilities in PostgreSQL throughout its versions with a series of blog posts. This is the fourth post of the series and we’ll talk about synchronous commit and its effects on fault tolerance and dependability of PostgreSQL. If you would like to witness the evolution progress from the beginning, please check the first three blog posts of the series below. Each post is independent, so you don't actually need to read one to understand another. Evolution of Fault Tolerance in PostgreSQL  Evolution of Fault Tolerance in PostgreSQL: Replication Phase  Evolution of Fault Tolerance in PostgreSQL: Time Travel Synchronous Commit By default, PostgreSQL (more…)
Evolution of Fault Tolerance in PostgreSQL: Time Travel

Evolution of Fault Tolerance in PostgreSQL: Time Travel

2ndQuadrant, Featured, Gulcin's PlanetPostgreSQL, PostgreSQL
PostgreSQL is an awesome project and it evolves at an amazing rate. We’ll focus on evolution of fault tolerance capabilities in PostgreSQL throughout its versions with a series of blog posts. This is the third post of the series and we’ll talk about timeline issues and their effects on fault tolerance and dependability of PostgreSQL. If you would like to witness the evolution progress from the beginning, please check the first two blog posts of the series: Evolution of Fault Tolerance in PostgreSQL  Evolution of Fault Tolerance in PostgreSQL: Replication Phase  Timelines The ability to restore the database to a previous point in time creates some complexities which we’ll cover some of the cases by explaining failover (Fig. 1), switchover (Fig. 2) and pg_rewind (Fig (more…)
Evolution of Fault Tolerance in PostgreSQL: Replication Phase

Evolution of Fault Tolerance in PostgreSQL: Replication Phase

2ndQuadrant, Featured, Gulcin's PlanetPostgreSQL, PostgreSQL
PostgreSQL is an awesome project and it evolves at an amazing rate. We’ll focus on evolution of fault tolerance capabilities in PostgreSQL throughout its versions with a series of blog posts. This is the second post of the series and we'll talk about replication and its importance on fault tolerance and dependability of PostgreSQL. If you would like to witness the evolution progress from the beginning, please check the first blog post of the series: Evolution of Fault Tolerance in PostgreSQL PostgreSQL Replication Database replication is the term we use to describe the technology used to maintain a copy of a set of data on a remote system.  Keeping a reliable copy of a running system is one of the biggest concerns of redundancy and we all like maintainable, easy-to-use and (more…)

Streaming replication slots in PostgreSQL 9.4

Craig's PlanetPostgreSQL
Streaming replication slots are a pending feature in PostgreSQL 9.4, as part of the logical changeset extraction feature. What are they for, what do you need to know, what changes? What are replication slots? Streaming replication slots are a new facility introduced in PostgreSQL 9.4. They are a persistent record of the state of a replica that is kept on the master server even when the replica is offline and disconnected. They aren't used for physical replication by default, so you'll only be dealing with them if you enable their use. This post explains what they do, why they're useful for physical replication, and why they're necessary for logical replication. Why slots? As part of the ongoing work Andres has been doing on log-streaming logical replication, changeset (more…)