Bazaar

“The Internet sees censorship as damage and routes around it” was a very motivating tagline during my early forays into the internet. Having grown up in Apartheid-era South Africa, where government control suppressed the free flow of ideas and ... [More] information, I was inspired by the idea of connecting with people all over the world to explore the cutting edge of science and technology. Today, people connect with peers and fellow explorers all over the world not just for science but also for arts, culture, friendship, relationships and more. The Internet is the glue that is turning us into a super-organism, for better or worse. And yes, there are dark sides to that easy exchange – internet comments alone will make you cry. But we should remember that the brain is smart even if individual brain cells are dumb, and negative, nasty elements on the Internet are just part of a healthy whole. There’s no Department of Morals I would trust to weed ‘em out or protect me or mine from them. Today, the pendulum is swinging back to government control of speech, most notably on the net. First, it became clear that total surveillance is the norm even amongst Western democratic governments (the “total information act” reborn).  Now we hear the UK government wants to be able to ban organisations without any evidence of involvement in illegal activities because they might “poison young minds”. Well, nonsense. Frustrated young minds will go off to Syria precisely BECAUSE they feel their avenues for discourse and debate are being shut down by an unfair and unrepresentative government – you couldn’t ask for a more compelling motivation for the next generation of home-grown anti-Western jihadists than to clamp down on discussion without recourse to due process. And yet, at the same time this is happening in the UK, protesters in Hong Kong are moving to peer-to-peer mechanisms to organise their protests precisely because of central control of the flow of information. One of the reasons I picked the certificate and security business back in the 1990′s was because I wanted to be part of letting people communicate privately and securely, for business and pleasure. I’m saddened now at the extent to which the promise of that security has been undermined by state pressure and bad actors in the business of trust. So I think it’s time that those of us who invest time, effort and money in the underpinnings of technology focus attention on the defensibility of the core freedoms at the heart of the internet. There are many efforts to fix this under way. The IETF is slowly become more conscious of the ways in which ideals can be undermined and the central role it can play in setting standards which are robust in the face of such inevitable pressure. But we can do more, and I’m writing now to invite applications for Fellowships at the Shuttleworth Foundation by leaders that are focused on these problems. TSF already has Fellows working on privacy in personal communications; we are interested in generalising that to the foundations of all communications. We already have a range of applications in this regard, I would welcome more. And I’d like to call attention to the Edgenet effort (distributing network capabilities, based on zero-mq) which is holding a sprint in Brussels October 30-31. 20 years ago, “Clipper” (a proposed mandatory US government back door, supported by the NSA) died on the vine thanks to a concerted effort by industry to show the risks inherent to such schemes. For two decades we’ve had the tide on the side of those who believe it’s more important for individuals and companies to be able to protect information than it is for security agencies to be able to monitor it. I’m glad that today, you are more likely to get into trouble if you don’t encrypt sensitive information in transit on your laptop than if you do. I believe that’s the right side to fight for and the right side for all of our security in the long term, too. But with mandatory back doors back on the table we can take nothing for granted – regulatory regimes can and do change, as often for the worse as for the better. If you care about these issues, please take action of one form or another. Law enforcement is important. There are huge dividends to a society in which people to make long term plans, which depends on their confidence in security and safety as much as their confidence in economic fairness and opportunity. But the agencies in whom we place this authority are human and tend over time, like any institution, to be more forceful in defending their own existence and privileges than they are in providing for the needs of others. There has never been an institution in history which has managed to avoid this cycle. For that reason, it’s important to ensure that law enforcement is done by due process; there are no short cuts which will not be abused sooner rather than later. Checks and balances are more important than knee-jerk responses to the last attack. Every society, even today’s modern Western society, is prone to abusive governance. We should fear our own darknesses more than we fear others. A fair society is one where laws are clear and crimes are punished in a way that is deemed fair. It is not one where thinking about crime is criminal, or one where talking about things that are unpalatable is criminal, or one where everybody is notionally protected from the arbitrary and the capricious. Over the past 20 years life has become safer, not more risky, for people living in an Internet-connected West. That’s no thanks to the listeners; it’s thanks to living in a period when the youth (the source of most trouble in the world) feel they have access to opportunity and ideas on a world-wide basis. We are pretty much certain to have hard challenges ahead in that regard. So for all the scaremongering about Chinese cyber-espionage and Russian cyber-warfare and criminal activity in darknets, we are better off keeping the Internet as a free-flowing and confidential medium than we are entrusting an agency with the job of monitoring us for inappropriate and dangerous ideas. And that’s something we’ll have to work for. [Less]

“The Internet sees censorship as damage and routes around it” was a very motivating tagline during my early forays into the internet. Having grown up in Apartheid-era South Africa, where government control suppressed the free flow of ideas and ... [More] information, I was inspired by the idea of connecting with people all over the world to explore the cutting edge of science and technology. Today, people connect with peers and fellow explorers all over the world not just for science but also for arts, culture, friendship, relationships and more. The Internet is the glue that is turning us into a super-organism, for better or worse. And yes, there are dark sides to that easy exchange – internet comments alone will make you cry. But we should remember that the brain is smart even if individual brain cells are dumb, and negative, nasty elements on the Internet are just part of a healthy whole. There’s no Department of Morals I would trust to weed ’em out or protect me or mine from them. Today, the pendulum is swinging back to government control of speech, most notably on the net. First, it became clear that total surveillance is the norm even amongst Western democratic governments (the “total information act” reborn).  Now we hear the UK government wants to be able to ban organisations without any evidence of involvement in illegal activities because they might “poison young minds”. Well, nonsense. Frustrated young minds will go off to Syria precisely BECAUSE they feel their avenues for discourse and debate are being shut down by an unfair and unrepresentative government – you couldn’t ask for a more compelling motivation for the next generation of home-grown anti-Western jihadists than to clamp down on discussion without recourse to due process. And yet, at the same time this is happening in the UK, protesters in Hong Kong are moving to peer-to-peer mechanisms to organise their protests precisely because of central control of the flow of information. One of the reasons I picked the certificate and security business back in the 1990’s was because I wanted to be part of letting people communicate privately and securely, for business and pleasure. I’m saddened now at the extent to which the promise of that security has been undermined by state pressure and bad actors in the business of trust. So I think it’s time that those of us who invest time, effort and money in the underpinnings of technology focus attention on the defensibility of the core freedoms at the heart of the internet. There are many efforts to fix this under way. The IETF is slowly become more conscious of the ways in which ideals can be undermined and the central role it can play in setting standards which are robust in the face of such inevitable pressure. But we can do more, and I’m writing now to invite applications for Fellowships at the Shuttleworth Foundation by leaders that are focused on these problems. TSF already has Fellows working on privacy in personal communications; we are interested in generalising that to the foundations of all communications. We already have a range of applications in this regard, I would welcome more. And I’d like to call attention to the Edgenet effort (distributing network capabilities, based on zero-mq) which is holding a sprint in Brussels October 30-31. 20 years ago, “Clipper” (a proposed mandatory US government back door, supported by the NSA) died on the vine thanks to a concerted effort by industry to show the risks inherent to such schemes. For two decades we’ve had the tide on the side of those who believe it’s more important for individuals and companies to be able to protect information than it is for security agencies to be able to monitor it. I’m glad that today, you are more likely to get into trouble if you don’t encrypt sensitive information in transit on your laptop than if you do. I believe that’s the right side to fight for and the right side for all of our security in the long term, too. But with mandatory back doors back on the table we can take nothing for granted – regulatory regimes can and do change, as often for the worse as for the better. If you care about these issues, please take action of one form or another. Law enforcement is important. There are huge dividends to a society in which people to make long term plans, which depends on their confidence in security and safety as much as their confidence in economic fairness and opportunity. But the agencies in whom we place this authority are human and tend over time, like any institution, to be more forceful in defending their own existence and privileges than they are in providing for the needs of others. There has never been an institution in history which has managed to avoid this cycle. For that reason, it’s important to ensure that law enforcement is done by due process; there are no short cuts which will not be abused sooner rather than later. Checks and balances are more important than knee-jerk responses to the last attack. Every society, even today’s modern Western society, is prone to abusive governance. We should fear our own darknesses more than we fear others. A fair society is one where laws are clear and crimes are punished in a way that is deemed fair. It is not one where thinking about crime is criminal, or one where talking about things that are unpalatable is criminal, or one where everybody is notionally protected from the arbitrary and the capricious. Over the past 20 years life has become safer, not more risky, for people living in an Internet-connected West. That’s no thanks to the listeners; it’s thanks to living in a period when the youth (the source of most trouble in the world) feel they have access to opportunity and ideas on a world-wide basis. We are pretty much certain to have hard challenges ahead in that regard. So for all the scaremongering about Chinese cyber-espionage and Russian cyber-warfare and criminal activity in darknets, we are better off keeping the Internet as a free-flowing and confidential medium than we are entrusting an agency with the job of monitoring us for inappropriate and dangerous ideas. And that’s something we’ll have to work for. [Less]

Quick question – we have Cloud Foundry in private beta now, is there anyone in the Ubuntu community who would like to use a Cloud Foundry instance if we were to operate that for Ubuntu members?

Quick question – we have Cloud Foundry in private beta now, is there anyone in the Ubuntu community who would like to use a Cloud Foundry instance if we were to operate that for Ubuntu members?

Be careful of headlines, they appeal to our sense of the obvious and the familiar, they entrench rather than challenge established stereotypes and memes. What one doesn’t read about every day is usually more interesting than what’s in the headlines. ... [More] And in the current round of global unease, what’s not being said – what we’ve failed to admit about our Western selves and our local allies – is central to the problems at hand. Both Iraq and Ukraine, under Western tutelage, failed to create states which welcome diversity. Both Iraq and the Ukraine aggressively marginalised significant communities, with the full knowledge and in some cases support of their Western benefactors. And in both cases, those disenfranchised communities have rallied their cause into wars of aggression. Reading the Western media one would think it’s clear who the aggressors are in both cases: Islamic State and Russia are “obvious bad actors” who’s behaviour needs to be met with stern action. Russia clearly has no business arming rebels with guns they use irresponsibly to tragic effect, and the Islamic State are clearly “a barbaric, evil force”. If those gross simplifications, reinforced in the Western media, define our debate and discussion on the subject then we are destined pursue some painful paths with little but frustration to show for the effort, and nasty thorns that fester indefinitely. If that sounds familiar it’s because yes, this is the same thing happening all over again. In a prior generation, only a decade ago, anger and frustration at 9/11 crowded out calm deliberation and a focus on the crimes in favour of shock and awe. Today, out of a lack of insight into the root cause of Ukrainian separatism and Islamic State’s attractiveness to a growing number across the Middle East and North Africa, we are about to compound our problems by slugging our way into a fight we should understand before we join. This is in no way to say that the behaviour of Islamic State or Russia are acceptable in modern society. They are not. But we must take responsibility for our own behaviour first and foremost; time and history are the best judges of the behaviour of others. In the case of the Ukraine, it’s important to know how miserable it has become for native Russian speakers born and raised in the Ukraine. People who have spent their entire lives as citizens of the Ukraine who happen to speak in Russian at home, at work, in church and at social events have found themselves discriminated against by official decree from Kiev. Friends of mine with family in Odessa tell me that there have been systematic attempts to undermine and disenfranchise Russian speaking in the Ukraine. “You may not speak in your home language in this school”. “This market can only be conducted in Ukrainian, not Russian”. It’s important to appreciate that being a Russian speaker in Ukraine doesn’t necessarily mean one is not perfectly happy to be a Ukranian. It just means that the Ukraine is a diverse cultural nation and has been throughout our lifetimes. This is a classic story of discrimination. Friends of mine who grew up in parts of Greece tell a similar story about the Macedonian culture being suppressed – schools being forced to punish Macedonian language spoken on the playground. What we need to recognise is that countries – nations – political structures – which adopt ethnic and cultural purity as a central idea, are dangerous breeding grounds for dissent, revolt and violence. It matters not if the government in question is an ally or a foe. Those lines get drawn and redrawn all the time (witness the dance currently under way to recruit Kurdish and Iranian assistance in dealing with IS, who would have thought!) based on marriages of convenience and hot button issues of the day. Turning a blind eye to thuggery and stupidity on the part of your allies is just as bad as making sure you’re hanging with the cool kids on the playground even if it happens that they are thugs and bullies –  stupid and shameful short-sightedness. In Iraq, the government installed and propped up with US money and materials (and the occasional slap on the back from Britain) took a pointedly sectarian approach to governance. People of particular religious communities were removed from positions of authority, disqualified from leadership, hunted and imprisoned and tortured. The US knew that leading figures in their Iraqi government were behaving in this way, but chose to continue supporting the government which protected these thugs because they were “our people”. That was a terrible mistake, because it is those very communities which have morphed into Islamic State. The modern nation states we call Iraq and the Ukraine – both with borders drawn in our modern lifetimes – are intrinsically diverse, intrinsically complex, intrinsically multi-cultural parts of the world. We should know that a failure to create governments of that diversity, for that diversity, will result in murderous resentment. And yet, now that the lines for that resentment are drawn, we are quick to choose sides, precisely the wrong position to take. What makes this so sad is that we know better and demand better for ourselves. The UK and the US are both countries who have diversity as a central tenet of their existence. Freedom of religion, freedom of expression, the right to a career and to leadership on the basis of competence rather than race or creed are major parts of our own identity. And yet we prop up states who take precisely the opposite approach, and wonder why they fail, again and again. We came to these values through blood and pain, we hold on to these values because we know first hand how miserable and how wasteful life becomes if we let human tribalism tear our communities apart. There are doors to universities in the UK on which have hung the bodies of religious dissidents, and we will never allow that to happen again at home, yet we prop up governments for whom that is the norm. The Irish Troubles was a war nobody could win. It was resolved through dialogue. South African terrorism in the 80′s was a war nobody could win. It was resolved through dialogue and the establishment of a state for everybody. Time and time again, “terrorism” and “barbarism” are words used to describe fractious movements by secure, distant seats of power, and in most of those cases, allowing that language to dominate our thinking leads to wars that nobody can win. Russia made a very grave error in arming Russian-speaking Ukranian separatists. But unless the West holds Kiev to account for its governance, unless it demands an open society free of discrimination, the misery there will continue. IS will gain nothing but contempt from its demonstrations of murder – there is no glory in violence on the defenceless and the innocent – but unless the West bends its might to the establishment of societies in Syria and Iraq in which these religious groups are welcome and free to pursue their ambitions, murder will be the only outlet for their frustration. Politicians think they have a new “clean” way to exert force – drones and airstrikes without “boots on the ground”. Believe me, that’s false. Remote control warfare will come home to fester on our streets.   [Less]

Be careful of headlines, they appeal to our sense of the obvious and the familiar, they entrench rather than challenge established stereotypes and memes. What one doesn’t read about every day is usually more interesting than what’s in the headlines. ... [More] And in the current round of global unease, what’s not being said – what we’ve failed to admit about our Western selves and our local allies – is central to the problems at hand. Both Iraq and Ukraine, under Western tutelage, failed to create states which welcome diversity. Both Iraq and the Ukraine aggressively marginalised significant communities, with the full knowledge and in some cases support of their Western benefactors. And in both cases, those disenfranchised communities have rallied their cause into wars of aggression. Reading the Western media one would think it’s clear who the aggressors are in both cases: Islamic State and Russia are “obvious bad actors” who’s behaviour needs to be met with stern action. Russia clearly has no business arming rebels with guns they use irresponsibly to tragic effect, and the Islamic State are clearly “a barbaric, evil force”. If those gross simplifications, reinforced in the Western media, define our debate and discussion on the subject then we are destined pursue some painful paths with little but frustration to show for the effort, and nasty thorns that fester indefinitely. If that sounds familiar it’s because yes, this is the same thing happening all over again. In a prior generation, only a decade ago, anger and frustration at 9/11 crowded out calm deliberation and a focus on the crimes in favour of shock and awe. Today, out of a lack of insight into the root cause of Ukrainian separatism and Islamic State’s attractiveness to a growing number across the Middle East and North Africa, we are about to compound our problems by slugging our way into a fight we should understand before we join. This is in no way to say that the behaviour of Islamic State or Russia are acceptable in modern society. They are not. But we must take responsibility for our own behaviour first and foremost; time and history are the best judges of the behaviour of others. In the case of the Ukraine, it’s important to know how miserable it has become for native Russian speakers born and raised in the Ukraine. People who have spent their entire lives as citizens of the Ukraine who happen to speak in Russian at home, at work, in church and at social events have found themselves discriminated against by official decree from Kiev. Friends of mine with family in Odessa tell me that there have been systematic attempts to undermine and disenfranchise Russian speaking in the Ukraine. “You may not speak in your home language in this school”. “This market can only be conducted in Ukrainian, not Russian”. It’s important to appreciate that being a Russian speaker in Ukraine doesn’t necessarily mean one is not perfectly happy to be a Ukranian. It just means that the Ukraine is a diverse cultural nation and has been throughout our lifetimes. This is a classic story of discrimination. Friends of mine who grew up in parts of Greece tell a similar story about the Macedonian culture being suppressed – schools being forced to punish Macedonian language spoken on the playground. What we need to recognise is that countries – nations – political structures – which adopt ethnic and cultural purity as a central idea, are dangerous breeding grounds for dissent, revolt and violence. It matters not if the government in question is an ally or a foe. Those lines get drawn and redrawn all the time (witness the dance currently under way to recruit Kurdish and Iranian assistance in dealing with IS, who would have thought!) based on marriages of convenience and hot button issues of the day. Turning a blind eye to thuggery and stupidity on the part of your allies is just as bad as making sure you’re hanging with the cool kids on the playground even if it happens that they are thugs and bullies –  stupid and shameful short-sightedness. In Iraq, the government installed and propped up with US money and materials (and the occasional slap on the back from Britain) took a pointedly sectarian approach to governance. People of particular religious communities were removed from positions of authority, disqualified from leadership, hunted and imprisoned and tortured. The US knew that leading figures in their Iraqi government were behaving in this way, but chose to continue supporting the government which protected these thugs because they were “our people”. That was a terrible mistake, because it is those very communities which have morphed into Islamic State. The modern nation states we call Iraq and the Ukraine – both with borders drawn in our modern lifetimes – are intrinsically diverse, intrinsically complex, intrinsically multi-cultural parts of the world. We should know that a failure to create governments of that diversity, for that diversity, will result in murderous resentment. And yet, now that the lines for that resentment are drawn, we are quick to choose sides, precisely the wrong position to take. What makes this so sad is that we know better and demand better for ourselves. The UK and the US are both countries who have diversity as a central tenet of their existence. Freedom of religion, freedom of expression, the right to a career and to leadership on the basis of competence rather than race or creed are major parts of our own identity. And yet we prop up states who take precisely the opposite approach, and wonder why they fail, again and again. We came to these values through blood and pain, we hold on to these values because we know first hand how miserable and how wasteful life becomes if we let human tribalism tear our communities apart. There are doors to universities in the UK on which have hung the bodies of religious dissidents, and we will never allow that to happen again at home, yet we prop up governments for whom that is the norm. The Irish Troubles was a war nobody could win. It was resolved through dialogue. South African terrorism in the 80’s was a war nobody could win. It was resolved through dialogue and the establishment of a state for everybody. Time and time again, “terrorism” and “barbarism” are words used to describe fractious movements by secure, distant seats of power, and in most of those cases, allowing that language to dominate our thinking leads to wars that nobody can win. Russia made a very grave error in arming Russian-speaking Ukranian separatists. But unless the West holds Kiev to account for its governance, unless it demands an open society free of discrimination, the misery there will continue. IS will gain nothing but contempt from its demonstrations of murder – there is no glory in violence on the defenceless and the innocent – but unless the West bends its might to the establishment of societies in Syria and Iraq in which these religious groups are welcome and free to pursue their ambitions, murder will be the only outlet for their frustration. Politicians think they have a new “clean” way to exert force – drones and airstrikes without “boots on the ground”. Believe me, that’s false. Remote control warfare will come home to fester on our streets.   [Less]

So Monty and Sean have recently blogged about about the structures (1, 2) they think may work better for OpenStack. I like the thrust of their thinking but had some mumblings of my own to add. Firstly, I very much like the focus on social structure ... [More] and needs – what our users and deployers need from us. That seems entirely right. And I very much like the getting away from TC picking winners and losers. That was never an enjoyable thing when I was on the TC, and I don’t think it has made OpenStack better. However, the thing that picking winners and losers did was that it allowed users to pick an API and depend on it. Because it was the ‘X API for OpenStack’. If we don’t pick winners, then there is no way to say that something is the ‘X API for OpenStack’, and that means that there is no forcing function for consistency between different deployer clouds. And so this appears to be why Ring 0 is needed: we think our users want consistency in being able to deploy their application to Rackspace or HP Helion. They want vendor neutrality, and by giving up winners-and-losers we give up vendor neutrality for our users. Thats the only explanation I can come up with for needing a Ring 0 – because its still winners and losers (e.g. picking an arbitrary project) keystone, grandfathering it in, if you will. If we really want to get out of the role of selecting projects, I think we need to avoid this. And we need to avoid it without losing vendor neutrality (or we need to give up the idea of vendor neutrality). One might say that we must pick winners for the very core just by its, but I don’t think thats true. If the core is small, many people will still want vendor neutrality higher up the stack. If the core is large, then we’ll have a larger % of APIs covered and stable granting vendor neutrality. So a core with fixed APIs will be under constant pressure to expand: not just from developers of projects, but from users that want API X to be fixed and guaranteed available and working a particular way at [most] OpenStack clouds. Ring 0 also fulfils a quality aspect – we can check that it all works together well in a realistic timeframe with our existing tooling. We are essentially proposing to pick functionality that we guarantee to users; and an API for that which they have everywhere, and the matching implementation we’ve tested. To pull from Monty’s post: “What does a basic end user need to get a compute resource that works and seems like a computer? (end user facet) What does Nova need to count on existing so that it can provide that. “ He then goes on to list a bunch of things, but most of them are not needed for that: We need Nova (its the only compute API in the project today). We don’t need keystone (Nova can run in noauth mode and deployers could just have e.g. Apache auth on top). We don’t need Neutron (Nova can do that itself). We don’t need cinder (use local volumes). We need Glance. We don’t need Designate. We don’t need a tonne of stuff that Nova has in it (e.g. quotas) – end users kicking off a simple machine have -very- basic needs. Consider the things that used to be in Nova: Deploying containers. Neutron. Cinder. Glance. Ironic. We’ve been slowly decomposing Nova (yay!!!) and if we keep doing so we can imagine getting to a point where there truly is a tightly focused code base that just does one thing well. I worry that we won’t get there unless we can ensure there is no pressure to be inside Nova to ‘win’. So there’s a choice between a relatively large set of APIs that make the guaranteed available APIs be comprehensive, or a small set that that will give users what they need just at the beginning but might not be broadly available and we’ll be depending on some unspecified process for the deployers to agree and consolidate around what ones they make available consistently. In sort one of the big reasons we were picking winners and losers in the TC was to consolidate effort around a single API – not implementation (keystone is already on its second implementation). All the angst about defcore and compatibility testing is going to be multiplied when there is lots of ecosystem choice around APIs above Ring 0, and the only reason that won’t be a problem for Ring 0 is that we’ll still be picking winners. How might we do this? One way would be to keep picking winners at the API definition level but not the implementation level, and make the competition be able to replace something entirely if they implement the existing API [and win hearts and minds of deployers]. That would open the door to everything being flexible – and its happened before with Keystone. Another way would be to not even have a Ring 0. Instead have a project/program that is aimed at delivering the reference API feature-set built out of a single, flat Big Tent – and allow that project/program to make localised decisions about what components to use (or not). Testing that all those things work together is not much different than the current approach, but we’d have separated out as a single cohesive entity the building of a product (Ring 0 is clearly a product) from the projects that might go into it. Projects that have unstable APIs would clearly be rejected by this team; projects with stable APIs would be considered etc. This team wouldn’t be the TC : they too would be subject to the TC’s rulings. We could even run multiple such teams – as hinted at by Dean Troyer one of the email thread posts. Running with that I’d then be suggesting IaaS product: selects components from the tent to make OpenStack/IaaS PaaS product: selects components from the tent to make OpenStack/PaaS CaaS product (containers) SaaS product (storage) NaaS product (networking – but things like NFV, not the basic Neutron we love today). Things where the thing you get is useful in its own right, not just as plumbing for a VM. So OpenStack/NaaS would have an API or set of APIs, and they’d be responsible for considering maturity, feature set, and so on, but wouldn’t ‘own’ Neutron, or ‘Neutron incubator’ or any other component – they would be a *cross project* team, focused at the product layer, rather than the component layer, which nearly all of our folk end up locked into today. Lastly Sean has also pointed out that we have large N N^2 communication issues – I think I’m proposing to drive the scope of any one project down to a minimum, which gives us more N, but shrinks the size within any project, so folk don’t burn out as easily, *and* so that it is easier to predict the impact of changes – clear contracts and APIs help a huge amount there. [Less]

Since its very early days subunit has had a single model – you run a process, it outputs test results. This works great, except when it doesn’t. On the up side, you have a one way pipeline – there’s no interactivity needed, which makes it very very ... [More] easy to write a subunit backend that e.g. testr can use. On the downside, there’s no interactivity, which means that anytime you want to do something with those tests, a new process is needed – and thats sometimes quite expensive – particularly in test suites with 10’s of thousands of tests.Now, for use in the development edit-execute loop, this is arguably ok, because one needs to load the new tests into memory anyway; but wouldn’t it be nice if tools like testr that run tests for you didn’t have to decide upfront exactly how they were going to run. If instead they could get things running straight away and then give progressively larger and larger units of work to be run, without forcing a new process (and thus new discovery directory walking and importing) ? Secondly, testr has an inconsistent interface – if testr is letting a user debug things to testr through to child workers in a chain, it needs to use something structured (e.g. subunit) and route stdin to the actual worker, but the final testr needs to unwrap everything – this is needlessly complex. Lastly, for some languages at least, its possibly to dynamically pick up new code at runtime – so a simple inotify loop and we could avoid new-process (and more importantly complete-enumeration) *entirely*, leading to very fast edit-test cycles. So, in this blog post I’m really running this idea up the flagpole, and trying to sketch out the interface – and hopefully get feedback on it. Taking subunit.run as an example process to do this to: There should be an option to change from one-shot to server mode In server mode, it will listen for commands somewhere (lets say stdin) On startup it might eager load the available tests One command would be list-tests – which would enumerate all the tests to its output channel (which is stdout today – so lets stay with that for now) Another would be run-tests, which would take a set of test ids, and then filter-and-run just those ids from the available tests, output, as it does today, going to stdout. Passing somewhat large sets of test ids in may be desirable, because some test runners perform fixture optimisations (e.g. bringing up DB servers or web servers) and test-at-a-time is pretty much worst case for that sort of environment. Another would be be std-in a command providing a packet of stdin – used for interacting with debuggers So that seems pretty approachable to me – we don’t even need an async loop in there, as long as we’re willing to patch select etc (for the stdin handling in some environments like Twisted). If we don’t want to monkey patch like that, we’ll need to make stdin a socketpair, and have an event loop running to shepard bytes from the real stdin to the one we let the rest of Python have. What about that nirvana above? If we assume inotify support, then list_tests (and run_tests) can just consult a changed-file list and reload those modules before continuing. Reloading them just-in-time would be likely to create havoc – I think reloading only when synchronised with test completion makes a great deal of sense. Would such a test server make sense in other languages?  What about e.g. testtools.run vs subunit.run – such a server wouldn’t want to use subunit, but perhaps a regular CLI UI would be nice… [Less]

Distributed databases are hard. Distributed databases where you don't have full control over what shards run which version of your software are even harder, because it becomes near impossible to deal with fallout when things go wrong. For lack of a ... [More] better term (is there one?), I'll refer to these databases as Autonomous Shard Distributed Databases. Distributed version control systems are an excellent example of such databases. They store file revisions and commit metadata in shards ("repositories") controlled by different people. Because of the nature of these systems, it is hard to weed out corrupt data if all shards ignorantly propagate broken data. There will be different people on different platforms running the database software that manages the individual shards. This makes it hard - if not impossible - to deploy software updates to all shards of a database in a reasonable amount of time (though a Chrome-like update mechanism might help here, if that was acceptable). This has consequences for the way in which you have to deal with every change to the database format and model. (e.g. imagine introducing a modification to the Linux kernel Git repository that required everybody to install a new version of Git). Defensive programming and a good format design from the start are essential. Git and its database format do really well in all of these regards. As I wrote in my retrospective, Bazaar has made a number of mistakes in this area, and that was a major source of user frustration. I think the followin gdesign I propose that every autonomous shard distributed databases should aim for the following: For the "base" format, keep it as simple as you possibly can. (KISS) The simpler the format, the smaller the chance of mistakes in the design that have to be corrected later. Similarly, it reduces the chances of mistakes in any implementation(s). In particular, there is no need for every piece of metadata to be a part of the core database format. (in the case of Git, I would argue that e.g. "author" might as well be a "meta-header") Corruption should be detected early and not propagated. This means there should be good tools to sanity check a database, and ideally some of these checks should be run automatically during everyday operations - e.g. when pushing changes to others or receiving them. If corruption does occur, there should be a way for as much of the database as possible to be recovered. A couple of corrupted objects should not render the entire database unusable. There should be tools for low-level access of the database, but also that the format and structure should be documented well enough for power users to understand it, examine files and extract data. No "hard" format changes (where clients /have/ to upgrade to access the new format). Not all users will instantly update to the latest and greatest version of the software. The lifecycle of enterprise Linux distributions is long enough that it might take three or four years for the majority of users to upgrade. Keep performance data like indexes in separate files. This makes it possible for older software to still read the data, albeit at a slower pace, and/or generate older format index files. New shards of the database should replicate the entire database if at all possible; having more copies of the data can't hurt if other shards go away or get corrupted. Having the data locally available also means users get quicker access to more data. Extensions to the database format that require hard format changes (think e.g. submodules) should only impact databases that actually use those extensions. Leave some room for structured arbitrary metadata, which gets propagated but that not all clients need to be able to understand and can safely ignore. (think fields like "Signed-Off-By", "Reviewed-By", "Fixes-Bug", etc) in commit metadata headers. [Less]

For a while, I've been wanting to set up configuration management for my home network. With half a dozen servers, a VPS and a workstation it is not big, but large enough to make it annoying to manually log into each machine for network-wide changes. ... [More] Most of the servers I have are low-end ARM machines, each responsible for a couple of tasks. Most of my machines run Debian or something derived from Debian. Oh, and I'm a member of the declarative school of configuration management. Propellor Propellor caught my eye earlier this year. Unlike some other configuration management tools, it doesn't come with its own custom language but it is written in Haskell, which I am already familiar with. It's also fairly simple, declarative, and seems to do most of the handful of things that I need. Propellor is essentially a Haskell application that you customize for your site. It works very similar to e.g. xmonad, where you write a bit of Haskell code for configuration which uses the upstream library code. When you run the application it takes your code and builds a binary from your code and the upstream libraries. Each host on which Propellor is used keeps a clone of the site-local Propellor git repository in /usr/local/propellor. Every time propellor runs (either because of a manual "spin", or from a cronjob it can set up for you), it fetches updates from the main site-local git repository, compiles the Haskell application and runs it. Setup Propellor was surprisingly easy to set up. Running propellor creates a clone of the upstream repository under ~/.propellor with a README file and some example configuration. I copied config-simple.hs to config.hs, updated it to reflect one of my hosts and within a few minutes I had a basic working propellor setup. You can use ./propellor <host> to trigger a run on a remote host. At the moment I have propellor working for some basic things - having certain Debian packages installed, a specific network configuration, mail setup, basic Kerberos configuration and certain SSH options set. This took surprisingly little time to set up, and it's been great being able to take full advantage of Haskell. Propellor comes with convenience functions for dealing with some commonly used packages, such as Apt, SSH and Postfix. For a lot of the other packages, you'll have to roll your own for now. I've written some extra code to make Propellor deal with Kerberos keytabs and Dovecot, which I hope to submit upstream. I don't have a lot of experience with other Free Software configuration management tools such as Puppet and Chef, but for my use case Propellor works very well. The main disadvantage of propellor for me so far is that it needs to build itself on each machine it runs on. This is fine for my workstation and high-end servers, but it is somewhat more problematic on e.g. my Raspberry Pi's. Compilation takes a while, and the Haskell compiler and libraries it needs amount to 500Mb worth of disk space on the tiny root partition. In order to work with Propellor, some Haskell knowledge is required. The Haskell in the configuration file is reasonably easy to understand if you keep it simple, but once the compiler spits out error messages then I suspect you'll have a hard time without any Haskell knowledge. Propellor relies on having a central repository with the configuration that it can pull from as root. Unlike Joey, I am wary of publishing the configuration of my home network and I don't have a highly available local git server setup. [Less]