Why are eval fields not in table?

[Span]

Hi,

Iam trying a simple query where i want to see the percentage of calls with a particular response time in splunk and somehow the percent field is coming as empty in the table.

index = xyz http_status=200 | stats count(request_ms) as web-calls by request_ms | eventstats sum(web-calls) as totalwb |eval percent=(web-calls*100/totalwb) | table request_ms web-calls totalwb percent

[richgalloway · Accepted solution]

The problem is with the web-calls field name.  The eval command is computing percent as (web-(calls*100/totalweb)), but since the web and calls fields don't exist they can't be subtracted so the percent field can't be computed.  Percent is set to null and is displayed as an empty field.  This is why hyphens should not be used in field names.  If the hyphen can't be changed then surround the field name in single quotes ('web-calls') so Splunk knows it's a field rather than an expression.