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Logstash Filters

Nicolas Frankel explains how the grok and dissect filters work in Logstash:

The Grok filter gets the job done. But it seems to suffer from performance issues, especially if the pattern doesn’t match. An alternative is to use the dissect filter instead, which is based on separators.

Unfortunately, there’s no app for that – but it’s much easier to write a separator-based filter than a regex-based one. The mapping equivalent to the above is:

%{timestamp} %{+timestamp} %{level}[%{application},%{traceId},%{spanId},%{zipkin}]\n
%{pid} %{}[%{thread}] %{class}:%{log}
(broken on 2 lines for better readability)

One of the big secrets to effective debugging of code is having good logging mechanisms in place.