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How can MySQL replicate? Let me count the ways

Percona Blog: MySQL Replication Overview

The Percona Blog has an Overview Of Different MySQL Replication Solutions. On top of the regular traditional Async Replication shown above, they also cover SemiSync, Group Replication, and Galera Cluster. Statement and Row Based Replication are contrasted.

Finally, “some misconceptions about replication” are being addressed, with “Replication is not a cluster”, “Replication is a HA solution”, “Replication replaces backups” and “Replication replaces Load Balancing”.

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Hipsterdoom with Mongobingo

Felix Gessert does a postmortem of the failed Parse startup and product: “The AWS and MongoDB Infrastructure of Parse: Lessons Learned“.

Technical problem II: the real problem and bottleneck was not the API servers but almost always the shared MongoDB database cluster.

And that was with MongoRocks (Mongo on RocksDB) and replacing the initial app in Ruby with a Go implementation of said thing, with WriteConcern = 1, and other horrible presets. All in all, this is like the perfect nightmare of startup architecture decisions.

Felix closes pointing at his current project:

If this idea sounds interesting to you, have a look at Baqend. It is a high-performance BaaS that focuses on web performance through transparent caching and scalability through auto-sharding and polyglot persistence.

Bingo. Also, found the Hipster.

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Using a blade center chassis to make Döner Kebap

I had the opportunity to play with a Blade Center Chassis with 16 Blades, each of them a Dual-E5 2690v4, so 56 threads (28 cores) times 16.

$ mkdir mprime; \
] cd mprime; \
] wget http://www.mersenne.org/ftp_root/gimps/p95v2810.linux64.tar.gz; \
] tar xvzf p95v2810.linux64.tar.gz; \
] ./mprime -m

running with “stress test only”, “mode 1 – small FFT” and 56 cores gets me quite a bit of power consumption.

Idle Blades is being reported as 140W, busy blades are 400W.

Images below the fold.

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On Normalcy: The rest times of truck drivers in Europe

DVZ Landverkehr reports (article in German):

LKW-Fahrer dürfen ihre wöchentliche Ruhezeit nicht im Fahrzeug verbringen. Zu diesem Ergebnis kommt Generalanwalt Evgeni Tanchev in seinen Schlussanträgen vom 2. Februar vor dem Europäischen Gerichtshof (EuGH). Hintergrund ist die Klage des Transportunternehmens Vaditrans gegen den Belgischen Staat.

(“Truck drivers must not spend their weekly downtime within the vehicle. That’s the conclusion drawn by general attorney Evgeni Tanchev in his final plea of Feb, 2nd before the ECJ. Background is a complaint of Vaditrans vs. Belgium”)

Most European countries require that the weekly downtime of truck drivers must not be spent in the vehicle. Vaditrans sued against this rule and the penalties for violation. European law allows daily downtimes to be spent in the cabin, but says nothing about weekly downtimes. Local rules in many states require that the drivers must not spent them on the vehicle.

The same proceedings are also reported in Eurotransport (article in German). The comments below the article rage against the ruling, with many commenters asking how this could possibly be implemented or how the ruling is unfair, cost intensive and generally wrong.

The definition of what is normal apparently can be distorted quite heavily – normal for most people obviously would be that drivers to park their vehicles next to a motel and sleep in proper rooms and beds, with proper meals and sanitary installations, every day, because that’s how jobs work in a civilization. Instead, people rage against requiring that drivers can and should be doing this at least on their weekends, claiming this to be impossible and abnormal.

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Open Fast Charging Alliance: Fast Carge operators in 6 countries partner

Five operators of fast charge networks for electric vehicles  in six european countries just announced to cooperate, reports electrek, creating a unified network of more than 500 fast chargers. Operators are Fastned (Netherlands), Sodetrel (France), Smatrics (Austria), Grønn Kontakt (Norway) and GOtthard FASTcharge (Switzerland). Notably absent, Germany.

The alliance will establish bilateral roaming agreements between themselves, allowing drivers that are members of one network to charge in all of these networks.

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The 2017 web is bloated and slow, and I am guilty, too.

Dan Luu has been benchmarking the web, using Webpagetest and other means. Turns out we have given up on optimization – we are doing too many requests, have too many dependencies and our files are just too large.

This site is no exception.

If you are running on Dialup connection or 3G speeds, or add packet loss, everything goes to hell, and most things don’t even load any more.

Only blog.fefe.de soldiers on.

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Lianas, Superhighways of the Canopy

The Atlantic reports research on the size of ant populations living in the treetops of forests in Panama. These treetops function as islands, if the tree in question has no vines connecting it to other trees nearby, with the size and diversity of the population being proportional to the tree size.

This changes as soon as the canopy is interconnected by lianas, which function as superhighways in the sky, connecting the various treetops into one single environment.

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Amnesty International: We have achieved surveillance society in Europe

The Amnesty Report “Dangerously Disproportionate: The Ever-Expanding National Security State in Europe” (PDF) goes through the states of Europes and their respective implementation of the surveillance state – emergency laws, principle of legality, privacy, freedom of expression, liberty, freedom of movement, and other categories are being investigated.

The summary states:

[B]y proposing, adopting and implementing wave after wave of counter-terrorism measures that have eroded the rule of law, enhanced executive powers, peeled away judicial controls, restricted freedom of expression and exposed everyone to government surveillance. Brick by brick, the edifice of rights protection that was so carefully constructed after the Second World War, is being dismantled.

This report aims to give a bird’s eye view of the national security landscape in Europe. It shows just how widespread and deep the “securitization” of Europe has become since 2014. The report reflects a world in which fear, alienation and prejudice are steadily chipping away at the cornerstones of the EU: fairness, equality and non-discrimination.

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MongoDB 3.4.0-rc3 passes Jepsen testing

MongoDB 3.4.0-rc3 with v1 replication protocol and majority write concern manages to pass Jepsen testing, says jepsen.io. That is quite an achievement.

Jepsen is a framework for distributed systems verification, with fault injection. It allows reliable diagnosis of Heisenbugs in distributed systems, with a clear analysis of the conditions that lead to the fault. By this, Jepsen testing allowed for the first time systematic testing and debugging of distributed systems and the real-world implementations of the consistency protocols in them. It’s built largely on the work of Kyle Kingsbury.

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FBI Rap Back

Wikipedia knows:

The [Chinese] Social Credit System is a proposed Chinese government initiative for developing a national reputation system. It has been reported to be intended to assign a “social credit” rating to every citizen based on government data regarding their economic and social status.

Xinhuanet has reported that the plan for the system “focuses on credit in four areas, including administrative affairs, commercial activities, social behavior, and the judicial system.”

The system has been an inspiration for the Black Mirror episode Nosedive, and US newspapers such as The Economost have been condemning it as Digital Totalitarian State.

Meanwhile The Intercepts reports on the FBI Rap Back program (““Rap” is an acronym for Record of Arrest and Prosecution; “Back” is short for background.”), which will implement exactly this:

What the program counts as “triggering events” differs depending on how subscribers configure their systems. In Missouri, where public school teachers are entered into the program, a police captain told a local paper that scanning fingerprints triggers the release of closed records, including charges that are not prosecuted and judicial decisions that result in dismissals or not guilty findings. […]

Lynch said it’s possible that employees could be fired for an arrest where they were exercising their First Amendment rights: filming public officials, attending protests, blocking streets. “It’s unclear if an employer that takes action based on the arrest would know the arrest is tied to First Amendment protected activity.”

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