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clonon Migrating Our Django App from MariaDB Galera to PostgreSQL and Patroni

This is very much our experience as well. As complexity increases, the marginal utility goes down, as operating concerns skyrocket.

You really need pretty special operational needs to run multi master relational databases.

It is am engineering tradeoff between complexity and fragility.

In our case Galera / PXC ended up with a significantly worse availability record than running our previous simple master slave failover system. See my other comment for more details.

clonon Migrating Our Django App from MariaDB Galera to PostgreSQL and Patroni

A much nicer approach, if you have the luxury of data disk usage below 50%.

clonon Migrating Our Django App from MariaDB Galera to PostgreSQL and Patroni

>MariaDB Galera is really easy to set up and maintain.

I take exception to that. When you log into all of your nodes after a network snafu and discover that every single node has attempted to perform a full state transfer, involving the destruction of the data directory...

  1. rm /var/mysql
  2. Attempt to do FST
  3. Crap happens

After a while, all nodes were left with no data. Off to backups :)

I am sure there is a way to prevent that, but Galera is still not easy ops wise.

clonon Migrating Our Django App from MariaDB Galera to PostgreSQL and Patroni

In my experience it did indeed remove a lot of deadlocks when we went from multi master writing to electing a single "writable" node. So in the end it is pretty much the same as deploying some read only slaves, plus automatic master promotion.

But not quite. Since even with this setup you might get a lot more weird deadlocks compared to a normal master slave setup, even running SELECT. Before we ditched Galera we were never really able to solve a couple classes of deadlocks, one involving CREATE TEMPORARY TABLE AS SELECT. Also, not all Galera deadlocks are really deadlocks, but actually Galera certification errors, reported as deadlocks to the client, so this distinction must be drawn as well.

Remember, a slave just stupidly replays stuff from the binlog onto a known state in a single thread, in the same serialised order that the master has already been able to commit. Galera on the other hand will attempt to certify and commit individual transactions. A certification does not really guarantee that the trx will be able to be committed when it comes to that. Not even in the case of single writer node, in many circumstances.

I'd say, after working with Galera/PXC for several years at considerable scale, that the premise of multi master writing only works in very narrow domains and even then you need to write a lot of application code to recover from Galera idiosyncrasies.

clonon Bird has raised $100M for electric scooter sharing

Reminds me of this: https://www.ecohelmet.com/

Essentially an origami helmet. Does anyone have some data points as to the efficacy of such a thing?

clonon Bird has raised $100M for electric scooter sharing

I agree with you, the way people will inevitably use them makes them unsafe to be used in the vast majority of the US urban scene.

In Europe, for example Amsterdam or Berlin, it would be a different story, however. They fit very well to the existing comprehensive system of bike lanes. They have a similar speed and manoeuvrability and also both the pedestrians and cyclist are already well conditioned for avoiding each other. Try stepping onto a bike lane in Berlin - you will be feeling really stupid in a hurry.

clonon Nuclear fusion on brink of being realised, say MIT scientists

That said, the material sciences advances required, especially high temperature superconducting magnets, simply were not there in the 70s. So a moonshot project to achieve it may have been a failure at massive costs, discouraging humanity from fusion research for a long time.

clonon Nuclear fusion on brink of being realised, say MIT scientists

https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcQV2HAS...

I enjoy the joke about the perpetually shifting fusion acquisition time frame, but it would be fair to add that in terms of actual funding, we have been under the "fusion never" level. I feel like the context for the saying has always been that the proper financing assumption holds.

clonon Turning web traffic into a Super Computer

This will only work if you can cheaply validate the work performed. Or send it to several distinct visitors and compare results, driving down the likelyhood that the results are bogus.

clonon U.S. Has Been Watching Russia's Nuclear-Powered Cruise Missiles Crash and Burn

Oh my.. Never thought of that. Surely it does not use the atmosphere as the primary circuit coolant?

clonon U.S. Has Been Watching Russia's Nuclear-Powered Cruise Missiles Crash and Burn

> At the most basic conceptual level, the weapon could conceivably reach supersonic speeds, fly at very low altitudes, and have effectively unlimited range thanks to its nuclear powerplant

If the Ruskies have developed a reactionless rocket engine capable of crashing further down range than experimental error, I would keep silent as well /s

clonon When is a senior engineer not a senior engineer?

Mindless over engineering is the hallmark of a mid level engineer - has acquired the technical skills, but not the sense to use them appropriately.

clonon A Simulated Stable Planetary System with 416 Planets in the Habitable Zone

That sounds just awesome.

clonon Opening the code of our X-Pack features

Thank you for the explanation. Data directory shared across all pods is the answer then.

Given that the process was automagic, I can see the potential for confusion.

Seems you are handling the fallout nicely though.

clonon Opening the code of our X-Pack features

How would you do a time limited trial for an immutable widely distributed Docker image?

There either has to be some fingerprinting and a phone home, or a licence you "manually" set to the env.

Since I am unaware of any sufficiently reliable host/cluster fingerprinting opportunity in say Kube, I assume it needs a licence to be configured in the pod yaml file.

What I don't understand is how this confusion can arise given the explicit licence installation.

Or where did I go wrong?

clonon Show HN: Jumprock.co – HTML Forms for Static Sites

Each generation invents their own tools. The cycle has reached FrontPage Server Side Includes. Soon the new PHP will emerge.

clonon Anatomy of a Ceph meltdown

> That's what I've done. Hardware RAID + XFS + NFS + backups, done. It wasn't HA, but at least I understood how to get it back up.

Looks like in this case you never actually needed what Ceph brings to the table - for a tremendous cost in complexity (and fragility, from personal anecdotal evidence) you can allow your dataset and -load to grow beyond the physical capabilities of a single node.

The HA argument in less demanding settings ends up being a cargo cult mostly. Your setup will probably produce higher reliability figures than running Ceph, assuming the lack of some serious engineering capabilities.

clonon SpaceX’s Falcon Heavy successfully launches

Is there cause for concern that the payload is spinning along what looks like roughly it's normal axis. Can we assume that they equipped it with some sort of means for attitude control?

Edit: referring to the Starman live feed: https://www.youtube.com/watch?v=aBr2kKAHN6M

clonon SpaceX’s Falcon Heavy successfully launches

Open a chapter about "History of the 21st century" and this image will be there.

clonon GitLab 10.4 released

I love GitLab for the CI/CD which is absolutely second to none.

But I have to second the resource usage - GitLab runs on beefier machines than our production database cluster. We are throwing everything at it, and performance still sucks. Both in terms of UI responsiveness and CI builders which are around 2-3 as slow as a local docker build.

For example, we have not yet seen a good enough reason to migrate our production database to use NVMe disks. But for GitLab server and CI builders - very much so (for a modest boost in performance).

But then again, I still think I get my money's worth.

clonon Protecting Google Cloud customers without impacting performance

Good for them, giving the credit to Paul Turner. Unusual for an enterprise to allow cracks in the corporate "We".

clonon GitHub down

It was 8 minutes and the stroy was already running in HN, checked it before status.github.com even. We rely too much on HN :P

clonon Doctors' plan for war on sugar

True. If we talk about everyone, then in a society where you are far more likely to suffer from obesity than starvation or malnutrition, "everyone" is doing a disservice to their children by not raising them to be the biggest most obnoxious food snobs ever.

clonon Doctors' plan for war on sugar

For me personally, rather well. By girlfriend has taught me to love chocolate so much that we only buy the most exquisite kind and savour it. A box of sweets can stay opened in the living room for weeks, sometimes with some pieces half-eaten.

I think it comes down to a certain healthy degree of (acquired) snobbery towards what you eat. If availability of food is no longer a concern, snobbery can very well take it's place! For example I could not imagine treating myself to eating a Hershey bar or Dunking donuts or whatever. Same as I wouldn't eat off the garbage bins behind a restaurant.

clonon Doctors' plan for war on sugar

Came here to say exactly this. A war is essentially a failure mode of the human civilization, when our innate biological ability to divide people into Us and Them gets the best of us and enables us to do unspeakable things. Such a failure mode must be recognised as such, but it's use is not to be diluted as an euphemism for solving everyday issues. Millions of people hastily buried in the 20th century would likely disagree with us using this word too lightly..

clonon Many packages suddenly disappeared

This is utter madness...

clonon Mailgun Security Incident and Important Customer Information

Postmark is really nice indeed, even though a bit on the pricey side.

Still, I can recommend their free tool to monitor DMARC: https://dmarc.postmarkapp.com/

clonon Mailgun Security Incident and Important Customer Information

At least it leaves a trail..

Many services state in the password reset emails that "if this was not initiated by you, ignore it", but it really should be the exact opposite - click the link below to report it!

clonon Mailgun Security Incident and Important Customer Information

Why would employees need access to client API keys, as opposed to just client ID?

Furthermore, this seems to indicate that the API keys are not hashed. I would expect some bits of the API key to work as an identifier and the rest of the bits treated as secret material (properly hashed).

As a Mailgun customer, this is concerning..

clonon Yes/No: Time tracking for a small software startup dev team?

In our outfit (operating for some years already) we were pondering the same question in regards to tracking support.

In the end we did a comprehensive analysis of how much time each client actually uses and the results were surprising. The vast majority of clients actually are not abusing the support channels with a few outliers.

So the takeaway for us was clearly to set up Basic and VIP support packages and spare our people the braindead overheads of time tracking.