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Downsampling: 1.8: you can have multiple retention per database. 2.0: one bucket , one retention. you need to downsample to a different bucket. Query: 1.8 : can only use FluxSQL 2.0: can use Flux and FluxSQL Continuous Query Continuous query is replaced with Task – you need to convert your InfluxSQL in Continuous query to Influx query and setup the task. Convert FLUXSQL to FLux query https://docs.influxdata.com/influxdb/v2.0/upgrade/v1-to-v2/migrate-cqs/ DownSampling data3 = from(bucket: “telegraf”) |> range(start: v.timeRangeStart, stop: v.timeRangeStop) |> filter(fn: (r) => (r._measurement =~ /system.*/)) data3 |> aggregateWindow(fn: mean, every: 1h) |> filter(fn: (r) => (exists r._value)) |> to(bucket: “telegraf_30min”, org: “MyHomeInflux”) Sampling is easy, don’tRead More →

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The code below is to create filmstrip using PuppeteerRead More →

are primarily used as a relay to the actual influxdb. The free influx db does not provide the high availability function. We use influxdb-relay or influxdb-srelay as the relay to the actual influxdb. With this approach your data can be saved in multiple influxdb copies. That’s the main purpose, but here are some difference between them. Influxdb-relay : can support HTTP & UDP protocol . Only supports write operation, it does not support query. The destination backend set is fixed. Have a cache to store data when the backend is down temporarily. If the backend is down for too long, the cache will not beRead More →

The following script will replace all bad keywords with *** .  The keyword variable accepts multiple keywords, they must be separated with a comma (,) .Read More →

I have a Macbook pro with this symptom: it’s not powered on , tried to hold the power button for long time , still nothing happen. I tried with and without power adaptor, result is still the same. I open the laptop and disconnect the battery, connect the power adapter , it turns on and working perfectly. Is the battery bad? i connect the battery back, it’s working fine. But then i shut it down, i can’t turn it on back. what is the issue? it’s because the power key is dead. The power key is a part of keyboard system. Solution? there are 3Read More →

High CPU usage is a common issue in every system, finding the root cause is not always easy. What the sign of a high CPU usage? I normally look at load avg , if the load avg is higher than the number of your CPU cores , then your system is overloaded. I have 8 cores, so my number is good. Sometimes we our load avg does not reach to the cpu cores , but we still see some application is slow, it’s because there is a process occupies the one single CPU core. My next step will be check the CPU usage per processRead More →

We tried to add Application Insights from Visual Studio Menu, the system said that version 2.15 installed, but we don’t see ApplicationInsights.config created. It turned out that our dotnet project is 4.5 while AppInsights version 2.15 requires dotnet must be 4.5.2 or higher. Visual Studio should show an error for this, but it doesnt. Solutions ? there are 2 ways you can fix it. 1) keep your current dotnet version and downgrade your appinsights version to 2.14 2) upgrade your dotnet version to the latest and also update appinsights to the latest as well. How to update AppInsights versiion , right click on the projectRead More →

Sometimes we have a function running too long more than we expect, we want to kill it after a certain time. For example, we have a function connecting to a remote share, the function we use to connect does not provide a timeout or we can’t change its timeout. Our solution is to build a timeout function to kill the function if it runs too long. I found this good and simple code: How do i use it?Read More →