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Author: kris

Theft of solar modules on the rise

Die Klimaretter are reporting: Theft of solar modules on the rise (article in German).

The article makes and supports the claim that solar modules are being stolen by organized crime in Germany, and explains ways to make that harder to perform and the goods easier to track. Solutions include marking and registration of all modules, GPS/GSM combos in components and special screws that require specific tools to remove panels without damaging them.

Wind turbines are also subject to theft and damage, but here mostly for the copper cables in them.

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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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