InfluxDB retention policy and data downsampling

By Atomstar on Saturday 15 June 2019 12:52 - Comments (1)
Category: Linux, Views: 647

Goal: set up data downsampling scheme on existing collectd data.

This article elaborates the official InfluxDB guide here (https://docs.influxdata.c...wnsampling_and_retention/)
where we already have a database with existing measurements that we want to
keep.

I'd like to downsample my collectd data on ping, memory, load, etc. data from
two machines. I only want high (minute) time resolution for a few days, then
downsample to save space.

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How many houses are not sold publicly/funda?

By Atomstar on Saturday 1 June 2019 09:45 - Comments (13)
Category: -, Views: 3.890

When we were looking to buy a house we did not use a purchase broker (aankoopmakelaar), but instead looked for houses ourselves online (mostly via funda.nl). One thing we often heard was that we’d miss houses were sold silently, from broker to broker. To verify this rumour, I bought kadaster data of recently sold houses in our neighbourhood and checked whether I could find these online.

Findings:
  1. 18 out of 20 houses had advertisements online
    1. 10 on funda
    2. 8 only on local brokers
  2. 2 houses were not advertised publicly, where one was sold at a very low price (perhaps sold to relatives?)
Method:
  1. Buy a few zip code reports from the kadaster
  2. For each house sold recently, search on google/funda
Conclusion: 90% of houses for sale are available online, of which at least 50% on Funda (some might have expired), and 40% on local websites. The hidden market could be limited to 10%.

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Improving wifi roaming without mesh routers

By Atomstar on Friday 5 April 2019 17:57 - Comments (6)
Category: Smarthome, Views: 1.928

Although I've managed to get WiFi connection in most corners of my house, I still had limited signal in my garden ('for one of those days you can squint your eyes in the sun trying to read the screen', a friend joked). Although this situation rarely happens, I still like to fix things in theory sometimes :p

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VLAN tagging on OpenWRT/managed switches

By Atomstar on Wednesday 3 April 2019 20:31 - Comments (5)
Category: Smarthome, Views: 2.172

I wanted to place my router somewhere not in the meterkast, so I used VLAN tagging on a managed switch to get the WAN data to the router and my LAN data back on the same wire (but different VLAN) to distribute to the rest of the house.

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Crimping network cables

By Atomstar on Sunday 31 March 2019 20:35 - Comments (13)
Category: Smarthome, Views: 3.282

Although most of us (including me) are familiar with making our own network cables/jacks, I recently wired network cable in my house learned some new things/abbreviations on cable thickness, cable material, pin termination, cross-over vs straight cables. I document my findings here for reference and case I forget in the future ;)

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