Does a lua script persist state across invocations?

[brunson]

Hi,

I'd like to implement some per tag metrics and I can't find whether a lua script can maintain state across separate invocations. Is the execution environment a blank slate for every log event a script handles or could I create an array of counters that are available on successive events?

Thank you for your help!

[edsiper]

by design it does not keep a state between iterations.

cc: @tarruda

[tarruda]

@edsiper we never reset the lua state, so yes, state is shared between log lines.
It can be useful keep state as shown in this xml parsing example: https://github.com/calyptia/fluent-bit-lua-samples/tree/main/xml-parsing

[brunson]

Thank you both for your quick responses.

Sincerely,
e.