Server Ownership Legalities

As I reported via Twitter late last week, we encountered an issue that got some of our mail delivery delayed by about a day and a half. I’ll explain more about what happened as I believe in openness on these matters, and also the experience has educational content for others. Our mail server doesn’t have […]

Today’s up-time requirements

When asking about up-time requirements set down in SLAs (Service Level Agreements) with our clients’ clients, we’d hear anything ranging from hours to the familiar five nines, but these days also simply 100% and otherwise penalties apply. From my perspective, there’s not much difference between five nines and 100%, 99.999% uptime over a year amounts […]

Quest for Resilience: Multi-DC Masters

This is a Request for Input. Dual MySQL masters with MMM in a single datacentre are in common use, and other setups like DRBD and of course VM/SAN based failover solutions are conceptually straightforward also. Thus, achieving various forms of resilience within a single data-centre is doable and not costly. Doing the same across multiple […]

Dogfood: making our systems more resilient

This is a “dogfood” type story (see below for explanation of the term)… Open Query has ideas on resilient architecture which it teaches (training) and recommends (consulting, support) to clients and the general public (blog, conferences, user group talks). Like many other businesses, when we first started we set up our infrastructure quickly and on […]

Continuity of power

Last night my residential area lost power for about 2 hours, between 2-4 am. This reminded me of something, and there’s analogies to MySQL infrastructure. Power companies have over recent years invested a lot of money in making the supply more reliable. But, it does fail occasionally still. From my perspective, the question becomes: is […]