What is the role of the stats, eval, and timechart commands in SPL? [Intermediate]
Answer
In SPL, stats calculates aggregate summaries, eval creates or modifies fields using expressions, and timechart builds time-series aggregations for charts. Together they cover most operational log analytics use cases.
Technical explanation
stats is used for counts, averages, percentiles, distinct counts, and grouping by fields.
eval is used for derived fields such as severity normalization, boolean flags, or latency buckets.
timechart groups results into time buckets, which makes it ideal for trends and incident timelines.
Hands-on example
Examples:
index=prod_app level=ERROR | stats count by service,error_code
index=prod_app | eval is_error=if(level='ERROR',1,0) | stats sum(is_error) by service
index=prod_app service=checkout | timechart span=5m count by level
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