Pacemaker and Corosync for virtual machines

By | Technical | One Comment

In the previous post we talked about using Corosync and Pacemaker to create highly available services. Subject to a couple of caveats, this is a good all-round approach. The caveats are what we’ll deal with today. Sometimes you’re dealing with software that won’t play nice when moved between systems, like a certain Enterpriseā„¢ database solution. […]

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Pacemaker and Corosync for HA services

By | Technical | No Comments

Now that we’ve got our terminology sorted out, we can talk about real deployments. Our most common HA deployments use the Linux HA suite, with multiple services managed by pacemaker. This is roughly the “stack” that we referred to in the first post in the series. We’ve already covered the resources involved, so we’ll focus […]

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Anatomy of an HA stack

By | Technical | No Comments

In what we plan to be a small series of articles about our high availability deployments, we thought we’d start by defining the key components in the stack and how they work together. In future we’ll cover some of the more specific details and things that need to be taken into consideration when deploying such […]

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Holy time-travellin’ DRBD, batman!

By | Technical | 6 Comments

Here at Anchor we’ve developed High-Availability (HA) systems for our customers to ensure they remain online in the event of catastrophic hardware failure. Most of our HA systems involve the use of DRBD, the Distributed Replicated Block Device. DRBD is like RAID-1 across a network. We’d like to share some notes on a recent issue […]

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GitHub: Speed matters

By | Technical | 4 Comments

Impressions from the first article (in its first day) and the first 24 hours of the GitHub migration, have caused us at Anchor to believe that; GitHub is just as popular as we thought, The migration was worth it, as things are running much faster (just check your twitter feeds, or better yet, check your […]

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When HA won’t play the way you want it to

By | Technical | No Comments

In an ideal world every service would support High Availability and Load Balancing, would scale up easily and cleanly and all of us systems administrators would be paid bucketloads to play golf all day while the computers did all the hard work. To quote Dylan Moran of Black Books fame, “Don’t make me laugh…bitterly”. I’ll […]

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