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UID:pretalx-2025-7TF3GB@pretalx.csnog.eu
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DESCRIPTION:In Energotel's IP network we need to store and visualisate few 
 thousands of sFlow samples per second. Common open source tools (mainly Ja
 va based) require huge amount of system resources and becomes quicky unres
 posible.\nBy using open source tools GoFlow2\, Kafka\, Clickhouse and Graf
 ana we have built own internal tool for parsing\, storing and visualisatin
 g sFlow data. The network size forced us to do many optimisations we want 
 to describe and share the know-how:\n- change default Clickhouse granulari
 ty\n- avoid storing calculated data (using Clickhouse's ALIAS data type)\n
 - implement double-sampling (data skipping to render wide time-window grap
 hs)\n- use big cache for uncompressed data\nand many more.\nThe tool is in
  use in Energotel for a few months. Screenshots from Grafana raised questi
 ons from many people\, what the tool we use.
DTSTAMP:20260726T065657Z
LOCATION:Hlavní místnost
SUMMARY:How we built sFlow visualization tool (open source) - Blažej Kraj
 ňák
URL:https://pretalx.csnog.eu/2025/talk/7TF3GB/
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