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Building a better DynamoDB throughput scaling tool, part 2

A month back I blogged about wanting a better throughput scaling tools for DynamoDB. Not having been able to find an existing tool that ticked all my boxes, I ended up scratching my own itch and developed a small Java tool that runs in the background, monitoring a set of DynamoDB tables. The tool satisfy […]

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The First Rule of Stealth Mode Is..

Apparently, according to the internet, the first rule of stealth mode is not to be that stealthy.. I don’t know, didn’t know, nor cared too much about that. For the last 2-3 years I’ve been working a lot in complete secrecy on a quantitative trading strategy. Only a few close friends and some family knew […]

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Space efficient Bloom filter index, 2x performance gain

To quote Wikipedia: A Bloom filter is a space-efficient probabilistic data structure that is used to test whether an element is a member of a set. This is often used by systems in order to avoid accessing slow media, like a disk. Take HBase or Cassandra for instance: Instead of reading their data files in […]

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Resource aware queue

For the TLDRs: This blog post presents the reasoning behing a project called ResourcePriorityBlockingQueue which is a blocking queue implementation that: Allows you to assign priority on tasks, just as with a PriorityBlockingQueue. Tasks may belong to task groups where each group may have a different priority. In that case, tasks are prioritized by group […]

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Oracle Coherence and MapReduce

I spend a lot of my time working with Oracle Coherence. If you’ve never heard of Coherence it can briefly be described as a¬†linearly scalable in-memory HashMap. By linearly scalable I mean a distributed HashMap, where each cluster member is responsible for storing a portion of the complete map. As everything is in-memory you maintain […]