Kafster, burrow, Clarebot, honeycomb

Log sampling

Kafka

  • Message queue / bus

  • Pub-sub model

  • Various data sources publish to it, consumers reading that data

FileBeat / Lumberjack

  • Run on the hosts

  • Reading log files from disk, then passes data to logstash or kafka

  • Original software mostly writing their logs to disk

  • Config:

    • If you want to see which log files are getting their data written to an ELK cluster and where it’s being sent, check the filebeat config (in /etc/filebeat.d) or lumberjack config (eg /etc/lumberjack.conf) on the host
    • You can then for instance search for “thingelk” to find entries with dest:”thingelk” and see which log files are being sent to thingelk
    • Or just generally scroll down to see the “files” section, where each element has

      • Fields - how the data will be constructed in the destination?,
      • Paths - which log files are being sent
      • Dest - where data will end up

Logrotate

  • logrotate used for Linux utilities, Java stuff like ES uses log4j

  • Config for httpd on thingelk hosts lives in /etc/logrotate_httpd.conf

  • In config

    • if it says daily at the top, the number lower down refers to that (so it might be 4 days, not 4 weeks)
    • delaycompress - create a daily log which contains logs from previous 24 hours, but then wait another 24 hours before compressing
    • The values at the top are the defaults, then they are overridden for individual file types
    • So for instance it might say rotate 4 at the top, then rotate 3 in the type you care about

      • This is a bit unusual though - often the global / default stuff is in a separate file.

StatsD

See https://docs.google.com/document/d/1ydXrsZX_g9uyvgMoZUovT0G8L5OcrXxRQDSWzw3ULDo/edit

Prometheus

  • More info here: https://docs.google.com/document/d/1ydXrsZX_g9uyvgMoZUovT0G8L5OcrXxRQDSWzw3ULDo/edit

  • Iike Graphite, Contains a time series data store

  • Julius Volz – original author

  • A pull model – actively scrapes data to store it

  • As well as providing a data store, also has an alert monitor

  • Can be queried to investigate the data

  • Prometheus can contain more info than Graphite

    • You can add arbitrary labels, but limited by cardinality of the values in the labels
    • More flexible, nor hierarchical, easier to slice things
  • Sliding window ephemeral store