Maybe you’ve heard about the recent attack on Bitcoin Gold exchanges, where the attackers stole some BTG using a form of double-spend attack. Now, you might start to wonder: How is that possible? The genius of blockchain is in preventing exactly this type of attack. But this crucial property holds only under certain network conditions. Let’s explore how such an attack is possible and what you can do to protect against it.

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This article closes the series about dumping Bitcoin forks, which started with this post. In the previous instalments we introduced various ways how to claim and dump them. The most valuable forks were described in more detail. This article will sum up all the other forks I claimed and dumped, since they do not deserve their own full post. Make sure, before doing anything, to read the safety notice in the introductory post.

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In any non-trivial system, failure is inevitable and incidents happen. How we deal with the incidents aftermath determines if they just cost money or we gain something from them. I’ve heard John Allspaw say a quote about incidents or outages, which fits perfectly: Incidents are unplanned investments in your company’s survival. So you have made this “investment”, everything is back up and running and now you should get as much value from it as possible.

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The story I am sure this has never happened to you, but try to imagine. Your on-call phone just got the message: The site is down! You open your Nagios dashboard and you are greeted by a sea of red. All Apache servers are not responding. The database connections are exhausted. Load balancers are screaming that they have no healthy backends. Everything else looks dead quiet. Everybody starts throwing around their guesses, what is going on.

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It becomes increasingly difficult to write something about particular fork, as they are getting indistinguishable. This time, we’ll dump BitcoinX (BCX). So in this article I will focus more on yet another method of claiming, which is mildly interesting, without commission and can be used for many forks. As usual, go read the Safety notice in my initial post in this series), if you haven’t done so yet. About BitcoinX So BCX is yet another fork, with a pretty homepage listing all the same stuff all the other forks do.

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If the ways I dumped Bitcoin Cash, Gold, Diamond and Super were too boring for you (they were, indeed), this time we’ll get our hands a bit more dirty. If you follow this story, you will become richer. That is, richer with knowledge, because there is not much to be made off dumping Bitcore (BTX). As usual, go read the Safety notice in my initial post in this series, if you haven’t done so yet.

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Getting into more obscure forks (but believe me, there are many more to come), I decided to do a double take, because I got rid of these two the exactly same way. The previous cases were both 1:1 forks, meaning you got one unit for one BTC. This time we’ll see first case of unit change, which I think is a clever trick, to be honest. If you haven’t done so yet, please read the Safety notice part in my introductory post to this series.

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The second most prominent Bitcoin fork was created about three months after Bitcoin Cash, which I wrote about in previous part of this series. If BCash wanted to solve the capacity problem by increasing block size, Bitcoin Gold (BTG) tried to “democratize” mining. The financial interests of their creators might also have played a tiny bit of a role in creating them, I suspect. If you haven’t done so yet, please read the Safety notice part in my introductory post to this series.

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Bitcoin Cash or BCash (BCH) was the first prominent fork, which started all the later craze by it’s relative success. If you are going to claim just one fork this should probably be it. Contrary to common sense, at the time of writing this article, it’s valued at about 15% of Bitcoin value. If you haven’t done so yet, please read the Safety notice part in my introductory post to this series.

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Bitcoin can be forked. It’s almost a magical process, doing a fork. Money, raining from the skies. You will realize how magical it seems, once you try to explain how the fork works to someone not familiar with cryptocurrencies and blockchain in general. What do you mean? You have some bitcoin, and then suddenly you have also some other coin? So the original bitcoin is split in two? Does Bitcoin lose half of it’s value then?

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When you have a microservice architecture, you have to deal with failures on many different levels. One of the patterns commonly used to deal with failures of remote calls is the circuit breaker. It helps preventing cascading failures, when a problem in one services causes exhaustion of resources in other services. Let’s take a look at one example, how one might go about implementing this pattern in a Node.js microservice.

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When we talk about complex systems, one of the studied properties is often the resilience of the system. By resilience we mean the capacity to recover from difficulties or failures. It’s often talked about in the realm of computer systems, but applies as well for others systems such as organizations. It’s helpful to classify the level of resilience, so that we can assess the current state of our system and decide if we want to invest in increasing it’s resilience, based on how critical the system is.

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I want to publish this experience, because the information is really spotty and hopefully this will save someone from going thru the same unpleasantness. I kind of hope that some officials responsible for this will read it, but that is a far fetch. OK, so our plan was to charter a sailboat in Dubrovnik and go visit Montenegro, especially the beautiful Bay of Kotor (Boka Kotorska). When talking to the the charter company, I specifically told them we want to go there and asked if the boat has all the paperwork.

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